Java tutorial
/* * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.io; import java.lang.ref.Reference; import java.lang.ref.ReferenceQueue; import java.lang.ref.SoftReference; import java.lang.ref.WeakReference; import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.UndeclaredThrowableException; import java.lang.reflect.Member; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.lang.reflect.Proxy; import java.security.AccessControlContext; import java.security.AccessController; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.security.PermissionCollection; import java.security.Permissions; import java.security.PrivilegedAction; import java.security.ProtectionDomain; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import jdk.internal.misc.Unsafe; import jdk.internal.reflect.CallerSensitive; import jdk.internal.reflect.Reflection; import jdk.internal.reflect.ReflectionFactory; import jdk.internal.access.SharedSecrets; import jdk.internal.access.JavaSecurityAccess; import sun.reflect.misc.ReflectUtil; import static java.io.ObjectStreamField.*; /** * Serialization's descriptor for classes. It contains the name and * serialVersionUID of the class. The ObjectStreamClass for a specific class * loaded in this Java VM can be found/created using the lookup method. * * <p>The algorithm to compute the SerialVersionUID is described in * <a href="{@docRoot}/../specs/serialization/class.html#stream-unique-identifiers"> * Object Serialization Specification, Section 4.6, Stream Unique Identifiers</a>. * * @author Mike Warres * @author Roger Riggs * @see ObjectStreamField * @see <a href="{@docRoot}/../specs/serialization/class.html"> * Object Serialization Specification, Section 4, Class Descriptors</a> * @since 1.1 */ public class ObjectStreamClass implements Serializable { /** serialPersistentFields value indicating no serializable fields */ public static final ObjectStreamField[] NO_FIELDS = new ObjectStreamField[0]; private static final long serialVersionUID = -6120832682080437368L; private static final ObjectStreamField[] serialPersistentFields = NO_FIELDS; /** reflection factory for obtaining serialization constructors */ private static final ReflectionFactory reflFactory = AccessController .doPrivileged(new ReflectionFactory.GetReflectionFactoryAction()); private static class Caches { /** cache mapping local classes -> descriptors */ static final ConcurrentMap<WeakClassKey, Reference<?>> localDescs = new ConcurrentHashMap<>(); /** cache mapping field group/local desc pairs -> field reflectors */ static final ConcurrentMap<FieldReflectorKey, Reference<?>> reflectors = new ConcurrentHashMap<>(); /** queue for WeakReferences to local classes */ private static final ReferenceQueue<Class<?>> localDescsQueue = new ReferenceQueue<>(); /** queue for WeakReferences to field reflectors keys */ private static final ReferenceQueue<Class<?>> reflectorsQueue = new ReferenceQueue<>(); } /** class associated with this descriptor (if any) */ private Class<?> cl; /** name of class represented by this descriptor */ private String name; /** serialVersionUID of represented class (null if not computed yet) */ private volatile Long suid; /** true if represents dynamic proxy class */ private boolean isProxy; /** true if represents enum type */ private boolean isEnum; /** true if represented class implements Serializable */ private boolean serializable; /** true if represented class implements Externalizable */ private boolean externalizable; /** true if desc has data written by class-defined writeObject method */ private boolean hasWriteObjectData; /** * true if desc has externalizable data written in block data format; this * must be true by default to accommodate ObjectInputStream subclasses which * override readClassDescriptor() to return class descriptors obtained from * ObjectStreamClass.lookup() (see 4461737) */ private boolean hasBlockExternalData = true; /** * Contains information about InvalidClassException instances to be thrown * when attempting operations on an invalid class. Note that instances of * this class are immutable and are potentially shared among * ObjectStreamClass instances. */ private static class ExceptionInfo { private final String className; private final String message; ExceptionInfo(String cn, String msg) { className = cn; message = msg; } /** * Returns (does not throw) an InvalidClassException instance created * from the information in this object, suitable for being thrown by * the caller. */ InvalidClassException newInvalidClassException() { return new InvalidClassException(className, message); } } /** exception (if any) thrown while attempting to resolve class */ private ClassNotFoundException resolveEx; /** exception (if any) to throw if non-enum deserialization attempted */ private ExceptionInfo deserializeEx; /** exception (if any) to throw if non-enum serialization attempted */ private ExceptionInfo serializeEx; /** exception (if any) to throw if default serialization attempted */ private ExceptionInfo defaultSerializeEx; /** serializable fields */ private ObjectStreamField[] fields; /** aggregate marshalled size of primitive fields */ private int primDataSize; /** number of non-primitive fields */ private int numObjFields; /** reflector for setting/getting serializable field values */ private FieldReflector fieldRefl; /** data layout of serialized objects described by this class desc */ private volatile ClassDataSlot[] dataLayout; /** serialization-appropriate constructor, or null if none */ private Constructor<?> cons; /** protection domains that need to be checked when calling the constructor */ private ProtectionDomain[] domains; /** class-defined writeObject method, or null if none */ private Method writeObjectMethod; /** class-defined readObject method, or null if none */ private Method readObjectMethod; /** class-defined readObjectNoData method, or null if none */ private Method readObjectNoDataMethod; /** class-defined writeReplace method, or null if none */ private Method writeReplaceMethod; /** class-defined readResolve method, or null if none */ private Method readResolveMethod; /** local class descriptor for represented class (may point to self) */ private ObjectStreamClass localDesc; /** superclass descriptor appearing in stream */ private ObjectStreamClass superDesc; /** true if, and only if, the object has been correctly initialized */ private boolean initialized; /** * Initializes native code. */ private static native void initNative(); static { initNative(); } /** * Find the descriptor for a class that can be serialized. Creates an * ObjectStreamClass instance if one does not exist yet for class. Null is * returned if the specified class does not implement java.io.Serializable * or java.io.Externalizable. * * @param cl class for which to get the descriptor * @return the class descriptor for the specified class */ public static ObjectStreamClass lookup(Class<?> cl) { return lookup(cl, false); } /** * Returns the descriptor for any class, regardless of whether it * implements {@link Serializable}. * * @param cl class for which to get the descriptor * @return the class descriptor for the specified class * @since 1.6 */ public static ObjectStreamClass lookupAny(Class<?> cl) { return lookup(cl, true); } /** * Returns the name of the class described by this descriptor. * This method returns the name of the class in the format that * is used by the {@link Class#getName} method. * * @return a string representing the name of the class */ public String getName() { return name; } /** * Return the serialVersionUID for this class. The serialVersionUID * defines a set of classes all with the same name that have evolved from a * common root class and agree to be serialized and deserialized using a * common format. NonSerializable classes have a serialVersionUID of 0L. * * @return the SUID of the class described by this descriptor */ public long getSerialVersionUID() { // REMIND: synchronize instead of relying on volatile? if (suid == null) { suid = AccessController.doPrivileged(new PrivilegedAction<Long>() { public Long run() { return computeDefaultSUID(cl); } }); } return suid.longValue(); } /** * Return the class in the local VM that this version is mapped to. Null * is returned if there is no corresponding local class. * * @return the <code>Class</code> instance that this descriptor represents */ @CallerSensitive public Class<?> forClass() { if (cl == null) { return null; } requireInitialized(); if (System.getSecurityManager() != null) { Class<?> caller = Reflection.getCallerClass(); if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(), cl.getClassLoader())) { ReflectUtil.checkPackageAccess(cl); } } return cl; } /** * Return an array of the fields of this serializable class. * * @return an array containing an element for each persistent field of * this class. Returns an array of length zero if there are no * fields. * @since 1.2 */ public ObjectStreamField[] getFields() { return getFields(true); } /** * Get the field of this class by name. * * @param name the name of the data field to look for * @return The ObjectStreamField object of the named field or null if * there is no such named field. */ public ObjectStreamField getField(String name) { return getField(name, null); } /** * Return a string describing this ObjectStreamClass. */ public String toString() { return name + ": static final long serialVersionUID = " + getSerialVersionUID() + "L;"; } /** * Looks up and returns class descriptor for given class, or null if class * is non-serializable and "all" is set to false. * * @param cl class to look up * @param all if true, return descriptors for all classes; if false, only * return descriptors for serializable classes */ static ObjectStreamClass lookup(Class<?> cl, boolean all) { if (!(all || Serializable.class.isAssignableFrom(cl))) { return null; } processQueue(Caches.localDescsQueue, Caches.localDescs); WeakClassKey key = new WeakClassKey(cl, Caches.localDescsQueue); Reference<?> ref = Caches.localDescs.get(key); Object entry = null; if (ref != null) { entry = ref.get(); } EntryFuture future = null; if (entry == null) { EntryFuture newEntry = new EntryFuture(); Reference<?> newRef = new SoftReference<>(newEntry); do { if (ref != null) { Caches.localDescs.remove(key, ref); } ref = Caches.localDescs.putIfAbsent(key, newRef); if (ref != null) { entry = ref.get(); } } while (ref != null && entry == null); if (entry == null) { future = newEntry; } } if (entry instanceof ObjectStreamClass) { // check common case first return (ObjectStreamClass) entry; } if (entry instanceof EntryFuture) { future = (EntryFuture) entry; if (future.getOwner() == Thread.currentThread()) { /* * Handle nested call situation described by 4803747: waiting * for future value to be set by a lookup() call further up the * stack will result in deadlock, so calculate and set the * future value here instead. */ entry = null; } else { entry = future.get(); } } if (entry == null) { try { entry = new ObjectStreamClass(cl); } catch (Throwable th) { entry = th; } if (future.set(entry)) { Caches.localDescs.put(key, new SoftReference<>(entry)); } else { // nested lookup call already set future entry = future.get(); } } if (entry instanceof ObjectStreamClass) { return (ObjectStreamClass) entry; } else if (entry instanceof RuntimeException) { throw (RuntimeException) entry; } else if (entry instanceof Error) { throw (Error) entry; } else { throw new InternalError("unexpected entry: " + entry); } } /** * Placeholder used in class descriptor and field reflector lookup tables * for an entry in the process of being initialized. (Internal) callers * which receive an EntryFuture belonging to another thread as the result * of a lookup should call the get() method of the EntryFuture; this will * return the actual entry once it is ready for use and has been set(). To * conserve objects, EntryFutures synchronize on themselves. */ private static class EntryFuture { private static final Object unset = new Object(); private final Thread owner = Thread.currentThread(); private Object entry = unset; /** * Attempts to set the value contained by this EntryFuture. If the * EntryFuture's value has not been set already, then the value is * saved, any callers blocked in the get() method are notified, and * true is returned. If the value has already been set, then no saving * or notification occurs, and false is returned. */ synchronized boolean set(Object entry) { if (this.entry != unset) { return false; } this.entry = entry; notifyAll(); return true; } /** * Returns the value contained by this EntryFuture, blocking if * necessary until a value is set. */ synchronized Object get() { boolean interrupted = false; while (entry == unset) { try { wait(); } catch (InterruptedException ex) { interrupted = true; } } if (interrupted) { AccessController.doPrivileged(new PrivilegedAction<>() { public Void run() { Thread.currentThread().interrupt(); return null; } }); } return entry; } /** * Returns the thread that created this EntryFuture. */ Thread getOwner() { return owner; } } /** * Creates local class descriptor representing given class. */ private ObjectStreamClass(final Class<?> cl) { this.cl = cl; name = cl.getName(); isProxy = Proxy.isProxyClass(cl); isEnum = Enum.class.isAssignableFrom(cl); serializable = Serializable.class.isAssignableFrom(cl); externalizable = Externalizable.class.isAssignableFrom(cl); Class<?> superCl = cl.getSuperclass(); superDesc = (superCl != null) ? lookup(superCl, false) : null; localDesc = this; if (serializable) { AccessController.doPrivileged(new PrivilegedAction<>() { public Void run() { if (isEnum) { suid = Long.valueOf(0); fields = NO_FIELDS; return null; } if (cl.isArray()) { fields = NO_FIELDS; return null; } suid = getDeclaredSUID(cl); try { fields = getSerialFields(cl); computeFieldOffsets(); } catch (InvalidClassException e) { serializeEx = deserializeEx = new ExceptionInfo(e.classname, e.getMessage()); fields = NO_FIELDS; } if (externalizable) { cons = getExternalizableConstructor(cl); } else { cons = getSerializableConstructor(cl); writeObjectMethod = getPrivateMethod(cl, "writeObject", new Class<?>[] { ObjectOutputStream.class }, Void.TYPE); readObjectMethod = getPrivateMethod(cl, "readObject", new Class<?>[] { ObjectInputStream.class }, Void.TYPE); readObjectNoDataMethod = getPrivateMethod(cl, "readObjectNoData", null, Void.TYPE); hasWriteObjectData = (writeObjectMethod != null); } domains = getProtectionDomains(cons, cl); writeReplaceMethod = getInheritableMethod(cl, "writeReplace", null, Object.class); readResolveMethod = getInheritableMethod(cl, "readResolve", null, Object.class); return null; } }); } else { suid = Long.valueOf(0); fields = NO_FIELDS; } try { fieldRefl = getReflector(fields, this); } catch (InvalidClassException ex) { // field mismatches impossible when matching local fields vs. self throw new InternalError(ex); } if (deserializeEx == null) { if (isEnum) { deserializeEx = new ExceptionInfo(name, "enum type"); } else if (cons == null) { deserializeEx = new ExceptionInfo(name, "no valid constructor"); } } for (int i = 0; i < fields.length; i++) { if (fields[i].getField() == null) { defaultSerializeEx = new ExceptionInfo(name, "unmatched serializable field(s) declared"); } } initialized = true; } /** * Creates blank class descriptor which should be initialized via a * subsequent call to initProxy(), initNonProxy() or readNonProxy(). */ ObjectStreamClass() { } /** * Creates a PermissionDomain that grants no permission. */ private ProtectionDomain noPermissionsDomain() { PermissionCollection perms = new Permissions(); perms.setReadOnly(); return new ProtectionDomain(null, perms); } /** * Aggregate the ProtectionDomains of all the classes that separate * a concrete class {@code cl} from its ancestor's class declaring * a constructor {@code cons}. * * If {@code cl} is defined by the boot loader, or the constructor * {@code cons} is declared by {@code cl}, or if there is no security * manager, then this method does nothing and {@code null} is returned. * * @param cons A constructor declared by {@code cl} or one of its * ancestors. * @param cl A concrete class, which is either the class declaring * the constructor {@code cons}, or a serializable subclass * of that class. * @return An array of ProtectionDomain representing the set of * ProtectionDomain that separate the concrete class {@code cl} * from its ancestor's declaring {@code cons}, or {@code null}. */ private ProtectionDomain[] getProtectionDomains(Constructor<?> cons, Class<?> cl) { ProtectionDomain[] domains = null; if (cons != null && cl.getClassLoader() != null && System.getSecurityManager() != null) { Class<?> cls = cl; Class<?> fnscl = cons.getDeclaringClass(); Set<ProtectionDomain> pds = null; while (cls != fnscl) { ProtectionDomain pd = cls.getProtectionDomain(); if (pd != null) { if (pds == null) pds = new HashSet<>(); pds.add(pd); } cls = cls.getSuperclass(); if (cls == null) { // that's not supposed to happen // make a ProtectionDomain with no permission. // should we throw instead? if (pds == null) pds = new HashSet<>(); else pds.clear(); pds.add(noPermissionsDomain()); break; } } if (pds != null) { domains = pds.toArray(new ProtectionDomain[0]); } } return domains; } /** * Initializes class descriptor representing a proxy class. */ void initProxy(Class<?> cl, ClassNotFoundException resolveEx, ObjectStreamClass superDesc) throws InvalidClassException { ObjectStreamClass osc = null; if (cl != null) { osc = lookup(cl, true); if (!osc.isProxy) { throw new InvalidClassException("cannot bind proxy descriptor to a non-proxy class"); } } this.cl = cl; this.resolveEx = resolveEx; this.superDesc = superDesc; isProxy = true; serializable = true; suid = Long.valueOf(0); fields = NO_FIELDS; if (osc != null) { localDesc = osc; name = localDesc.name; externalizable = localDesc.externalizable; writeReplaceMethod = localDesc.writeReplaceMethod; readResolveMethod = localDesc.readResolveMethod; deserializeEx = localDesc.deserializeEx; domains = localDesc.domains; cons = localDesc.cons; } fieldRefl = getReflector(fields, localDesc); initialized = true; } /** * Initializes class descriptor representing a non-proxy class. */ void initNonProxy(ObjectStreamClass model, Class<?> cl, ClassNotFoundException resolveEx, ObjectStreamClass superDesc) throws InvalidClassException { long suid = Long.valueOf(model.getSerialVersionUID()); ObjectStreamClass osc = null; if (cl != null) { osc = lookup(cl, true); if (osc.isProxy) { throw new InvalidClassException("cannot bind non-proxy descriptor to a proxy class"); } if (model.isEnum != osc.isEnum) { throw new InvalidClassException(model.isEnum ? "cannot bind enum descriptor to a non-enum class" : "cannot bind non-enum descriptor to an enum class"); } if (model.serializable == osc.serializable && !cl.isArray() && suid != osc.getSerialVersionUID()) { throw new InvalidClassException(osc.name, "local class incompatible: " + "stream classdesc serialVersionUID = " + suid + ", local class serialVersionUID = " + osc.getSerialVersionUID()); } if (!classNamesEqual(model.name, osc.name)) { throw new InvalidClassException(osc.name, "local class name incompatible with stream class " + "name \"" + model.name + "\""); } if (!model.isEnum) { if ((model.serializable == osc.serializable) && (model.externalizable != osc.externalizable)) { throw new InvalidClassException(osc.name, "Serializable incompatible with Externalizable"); } if ((model.serializable != osc.serializable) || (model.externalizable != osc.externalizable) || !(model.serializable || model.externalizable)) { deserializeEx = new ExceptionInfo(osc.name, "class invalid for deserialization"); } } } this.cl = cl; this.resolveEx = resolveEx; this.superDesc = superDesc; name = model.name; this.suid = suid; isProxy = false; isEnum = model.isEnum; serializable = model.serializable; externalizable = model.externalizable; hasBlockExternalData = model.hasBlockExternalData; hasWriteObjectData = model.hasWriteObjectData; fields = model.fields; primDataSize = model.primDataSize; numObjFields = model.numObjFields; if (osc != null) { localDesc = osc; writeObjectMethod = localDesc.writeObjectMethod; readObjectMethod = localDesc.readObjectMethod; readObjectNoDataMethod = localDesc.readObjectNoDataMethod; writeReplaceMethod = localDesc.writeReplaceMethod; readResolveMethod = localDesc.readResolveMethod; if (deserializeEx == null) { deserializeEx = localDesc.deserializeEx; } domains = localDesc.domains; cons = localDesc.cons; } fieldRefl = getReflector(fields, localDesc); // reassign to matched fields so as to reflect local unshared settings fields = fieldRefl.getFields(); initialized = true; } /** * Reads non-proxy class descriptor information from given input stream. * The resulting class descriptor is not fully functional; it can only be * used as input to the ObjectInputStream.resolveClass() and * ObjectStreamClass.initNonProxy() methods. */ void readNonProxy(ObjectInputStream in) throws IOException, ClassNotFoundException { name = in.readUTF(); suid = Long.valueOf(in.readLong()); isProxy = false; byte flags = in.readByte(); hasWriteObjectData = ((flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0); hasBlockExternalData = ((flags & ObjectStreamConstants.SC_BLOCK_DATA) != 0); externalizable = ((flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0); boolean sflag = ((flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0); if (externalizable && sflag) { throw new InvalidClassException(name, "serializable and externalizable flags conflict"); } serializable = externalizable || sflag; isEnum = ((flags & ObjectStreamConstants.SC_ENUM) != 0); if (isEnum && suid.longValue() != 0L) { throw new InvalidClassException(name, "enum descriptor has non-zero serialVersionUID: " + suid); } int numFields = in.readShort(); if (isEnum && numFields != 0) { throw new InvalidClassException(name, "enum descriptor has non-zero field count: " + numFields); } fields = (numFields > 0) ? new ObjectStreamField[numFields] : NO_FIELDS; for (int i = 0; i < numFields; i++) { char tcode = (char) in.readByte(); String fname = in.readUTF(); String signature = ((tcode == 'L') || (tcode == '[')) ? in.readTypeString() : new String(new char[] { tcode }); try { fields[i] = new ObjectStreamField(fname, signature, false); } catch (RuntimeException e) { throw (IOException) new InvalidClassException(name, "invalid descriptor for field " + fname) .initCause(e); } } computeFieldOffsets(); } /** * Writes non-proxy class descriptor information to given output stream. */ void writeNonProxy(ObjectOutputStream out) throws IOException { out.writeUTF(name); out.writeLong(getSerialVersionUID()); byte flags = 0; if (externalizable) { flags |= ObjectStreamConstants.SC_EXTERNALIZABLE; int protocol = out.getProtocolVersion(); if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) { flags |= ObjectStreamConstants.SC_BLOCK_DATA; } } else if (serializable) { flags |= ObjectStreamConstants.SC_SERIALIZABLE; } if (hasWriteObjectData) { flags |= ObjectStreamConstants.SC_WRITE_METHOD; } if (isEnum) { flags |= ObjectStreamConstants.SC_ENUM; } out.writeByte(flags); out.writeShort(fields.length); for (int i = 0; i < fields.length; i++) { ObjectStreamField f = fields[i]; out.writeByte(f.getTypeCode()); out.writeUTF(f.getName()); if (!f.isPrimitive()) { out.writeTypeString(f.getTypeString()); } } } /** * Returns ClassNotFoundException (if any) thrown while attempting to * resolve local class corresponding to this class descriptor. */ ClassNotFoundException getResolveException() { return resolveEx; } /** * Throws InternalError if not initialized. */ private final void requireInitialized() { if (!initialized) throw new InternalError("Unexpected call when not initialized"); } /** * Throws an InvalidClassException if object instances referencing this * class descriptor should not be allowed to deserialize. This method does * not apply to deserialization of enum constants. */ void checkDeserialize() throws InvalidClassException { requireInitialized(); if (deserializeEx != null) { throw deserializeEx.newInvalidClassException(); } } /** * Throws an InvalidClassException if objects whose class is represented by * this descriptor should not be allowed to serialize. This method does * not apply to serialization of enum constants. */ void checkSerialize() throws InvalidClassException { requireInitialized(); if (serializeEx != null) { throw serializeEx.newInvalidClassException(); } } /** * Throws an InvalidClassException if objects whose class is represented by * this descriptor should not be permitted to use default serialization * (e.g., if the class declares serializable fields that do not correspond * to actual fields, and hence must use the GetField API). This method * does not apply to deserialization of enum constants. */ void checkDefaultSerialize() throws InvalidClassException { requireInitialized(); if (defaultSerializeEx != null) { throw defaultSerializeEx.newInvalidClassException(); } } /** * Returns superclass descriptor. Note that on the receiving side, the * superclass descriptor may be bound to a class that is not a superclass * of the subclass descriptor's bound class. */ ObjectStreamClass getSuperDesc() { requireInitialized(); return superDesc; } /** * Returns the "local" class descriptor for the class associated with this * class descriptor (i.e., the result of * ObjectStreamClass.lookup(this.forClass())) or null if there is no class * associated with this descriptor. */ ObjectStreamClass getLocalDesc() { requireInitialized(); return localDesc; } /** * Returns arrays of ObjectStreamFields representing the serializable * fields of the represented class. If copy is true, a clone of this class * descriptor's field array is returned, otherwise the array itself is * returned. */ ObjectStreamField[] getFields(boolean copy) { return copy ? fields.clone() : fields; } /** * Looks up a serializable field of the represented class by name and type. * A specified type of null matches all types, Object.class matches all * non-primitive types, and any other non-null type matches assignable * types only. Returns matching field, or null if no match found. */ ObjectStreamField getField(String name, Class<?> type) { for (int i = 0; i < fields.length; i++) { ObjectStreamField f = fields[i]; if (f.getName().equals(name)) { if (type == null || (type == Object.class && !f.isPrimitive())) { return f; } Class<?> ftype = f.getType(); if (ftype != null && type.isAssignableFrom(ftype)) { return f; } } } return null; } /** * Returns true if class descriptor represents a dynamic proxy class, false * otherwise. */ boolean isProxy() { requireInitialized(); return isProxy; } /** * Returns true if class descriptor represents an enum type, false * otherwise. */ boolean isEnum() { requireInitialized(); return isEnum; } /** * Returns true if represented class implements Externalizable, false * otherwise. */ boolean isExternalizable() { requireInitialized(); return externalizable; } /** * Returns true if represented class implements Serializable, false * otherwise. */ boolean isSerializable() { requireInitialized(); return serializable; } /** * Returns true if class descriptor represents externalizable class that * has written its data in 1.2 (block data) format, false otherwise. */ boolean hasBlockExternalData() { requireInitialized(); return hasBlockExternalData; } /** * Returns true if class descriptor represents serializable (but not * externalizable) class which has written its data via a custom * writeObject() method, false otherwise. */ boolean hasWriteObjectData() { requireInitialized(); return hasWriteObjectData; } /** * Returns true if represented class is serializable/externalizable and can * be instantiated by the serialization runtime--i.e., if it is * externalizable and defines a public no-arg constructor, or if it is * non-externalizable and its first non-serializable superclass defines an * accessible no-arg constructor. Otherwise, returns false. */ boolean isInstantiable() { requireInitialized(); return (cons != null); } /** * Returns true if represented class is serializable (but not * externalizable) and defines a conformant writeObject method. Otherwise, * returns false. */ boolean hasWriteObjectMethod() { requireInitialized(); return (writeObjectMethod != null); } /** * Returns true if represented class is serializable (but not * externalizable) and defines a conformant readObject method. Otherwise, * returns false. */ boolean hasReadObjectMethod() { requireInitialized(); return (readObjectMethod != null); } /** * Returns true if represented class is serializable (but not * externalizable) and defines a conformant readObjectNoData method. * Otherwise, returns false. */ boolean hasReadObjectNoDataMethod() { requireInitialized(); return (readObjectNoDataMethod != null); } /** * Returns true if represented class is serializable or externalizable and * defines a conformant writeReplace method. Otherwise, returns false. */ boolean hasWriteReplaceMethod() { requireInitialized(); return (writeReplaceMethod != null); } /** * Returns true if represented class is serializable or externalizable and * defines a conformant readResolve method. Otherwise, returns false. */ boolean hasReadResolveMethod() { requireInitialized(); return (readResolveMethod != null); } /** * Creates a new instance of the represented class. If the class is * externalizable, invokes its public no-arg constructor; otherwise, if the * class is serializable, invokes the no-arg constructor of the first * non-serializable superclass. Throws UnsupportedOperationException if * this class descriptor is not associated with a class, if the associated * class is non-serializable or if the appropriate no-arg constructor is * inaccessible/unavailable. */ Object newInstance() throws InstantiationException, InvocationTargetException, UnsupportedOperationException { requireInitialized(); if (cons != null) { try { if (domains == null || domains.length == 0) { return cons.newInstance(); } else { JavaSecurityAccess jsa = SharedSecrets.getJavaSecurityAccess(); PrivilegedAction<?> pea = () -> { try { return cons.newInstance(); } catch (InstantiationException | InvocationTargetException | IllegalAccessException x) { throw new UndeclaredThrowableException(x); } }; // Can't use PrivilegedExceptionAction with jsa try { return jsa.doIntersectionPrivilege(pea, AccessController.getContext(), new AccessControlContext(domains)); } catch (UndeclaredThrowableException x) { Throwable cause = x.getCause(); if (cause instanceof InstantiationException) throw (InstantiationException) cause; if (cause instanceof InvocationTargetException) throw (InvocationTargetException) cause; if (cause instanceof IllegalAccessException) throw (IllegalAccessException) cause; // not supposed to happen throw x; } } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Invokes the writeObject method of the represented serializable class. * Throws UnsupportedOperationException if this class descriptor is not * associated with a class, or if the class is externalizable, * non-serializable or does not define writeObject. */ void invokeWriteObject(Object obj, ObjectOutputStream out) throws IOException, UnsupportedOperationException { requireInitialized(); if (writeObjectMethod != null) { try { writeObjectMethod.invoke(obj, new Object[] { out }); } catch (InvocationTargetException ex) { Throwable th = ex.getTargetException(); if (th instanceof IOException) { throw (IOException) th; } else { throwMiscException(th); } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Invokes the readObject method of the represented serializable class. * Throws UnsupportedOperationException if this class descriptor is not * associated with a class, or if the class is externalizable, * non-serializable or does not define readObject. */ void invokeReadObject(Object obj, ObjectInputStream in) throws ClassNotFoundException, IOException, UnsupportedOperationException { requireInitialized(); if (readObjectMethod != null) { try { readObjectMethod.invoke(obj, new Object[] { in }); } catch (InvocationTargetException ex) { Throwable th = ex.getTargetException(); if (th instanceof ClassNotFoundException) { throw (ClassNotFoundException) th; } else if (th instanceof IOException) { throw (IOException) th; } else { throwMiscException(th); } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Invokes the readObjectNoData method of the represented serializable * class. Throws UnsupportedOperationException if this class descriptor is * not associated with a class, or if the class is externalizable, * non-serializable or does not define readObjectNoData. */ void invokeReadObjectNoData(Object obj) throws IOException, UnsupportedOperationException { requireInitialized(); if (readObjectNoDataMethod != null) { try { readObjectNoDataMethod.invoke(obj, (Object[]) null); } catch (InvocationTargetException ex) { Throwable th = ex.getTargetException(); if (th instanceof ObjectStreamException) { throw (ObjectStreamException) th; } else { throwMiscException(th); } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Invokes the writeReplace method of the represented serializable class and * returns the result. Throws UnsupportedOperationException if this class * descriptor is not associated with a class, or if the class is * non-serializable or does not define writeReplace. */ Object invokeWriteReplace(Object obj) throws IOException, UnsupportedOperationException { requireInitialized(); if (writeReplaceMethod != null) { try { return writeReplaceMethod.invoke(obj, (Object[]) null); } catch (InvocationTargetException ex) { Throwable th = ex.getTargetException(); if (th instanceof ObjectStreamException) { throw (ObjectStreamException) th; } else { throwMiscException(th); throw new InternalError(th); // never reached } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Invokes the readResolve method of the represented serializable class and * returns the result. Throws UnsupportedOperationException if this class * descriptor is not associated with a class, or if the class is * non-serializable or does not define readResolve. */ Object invokeReadResolve(Object obj) throws IOException, UnsupportedOperationException { requireInitialized(); if (readResolveMethod != null) { try { return readResolveMethod.invoke(obj, (Object[]) null); } catch (InvocationTargetException ex) { Throwable th = ex.getTargetException(); if (th instanceof ObjectStreamException) { throw (ObjectStreamException) th; } else { throwMiscException(th); throw new InternalError(th); // never reached } } catch (IllegalAccessException ex) { // should not occur, as access checks have been suppressed throw new InternalError(ex); } } else { throw new UnsupportedOperationException(); } } /** * Class representing the portion of an object's serialized form allotted * to data described by a given class descriptor. If "hasData" is false, * the object's serialized form does not contain data associated with the * class descriptor. */ static class ClassDataSlot { /** class descriptor "occupying" this slot */ final ObjectStreamClass desc; /** true if serialized form includes data for this slot's descriptor */ final boolean hasData; ClassDataSlot(ObjectStreamClass desc, boolean hasData) { this.desc = desc; this.hasData = hasData; } } /** * Returns array of ClassDataSlot instances representing the data layout * (including superclass data) for serialized objects described by this * class descriptor. ClassDataSlots are ordered by inheritance with those * containing "higher" superclasses appearing first. The final * ClassDataSlot contains a reference to this descriptor. */ ClassDataSlot[] getClassDataLayout() throws InvalidClassException { // REMIND: synchronize instead of relying on volatile? if (dataLayout == null) { dataLayout = getClassDataLayout0(); } return dataLayout; } private ClassDataSlot[] getClassDataLayout0() throws InvalidClassException { ArrayList<ClassDataSlot> slots = new ArrayList<>(); Class<?> start = cl, end = cl; // locate closest non-serializable superclass while (end != null && Serializable.class.isAssignableFrom(end)) { end = end.getSuperclass(); } HashSet<String> oscNames = new HashSet<>(3); for (ObjectStreamClass d = this; d != null; d = d.superDesc) { if (oscNames.contains(d.name)) { throw new InvalidClassException("Circular reference."); } else { oscNames.add(d.name); } // search up inheritance hierarchy for class with matching name String searchName = (d.cl != null) ? d.cl.getName() : d.name; Class<?> match = null; for (Class<?> c = start; c != end; c = c.getSuperclass()) { if (searchName.equals(c.getName())) { match = c; break; } } // add "no data" slot for each unmatched class below match if (match != null) { for (Class<?> c = start; c != match; c = c.getSuperclass()) { slots.add(new ClassDataSlot(ObjectStreamClass.lookup(c, true), false)); } start = match.getSuperclass(); } // record descriptor/class pairing slots.add(new ClassDataSlot(d.getVariantFor(match), true)); } // add "no data" slot for any leftover unmatched classes for (Class<?> c = start; c != end; c = c.getSuperclass()) { slots.add(new ClassDataSlot(ObjectStreamClass.lookup(c, true), false)); } // order slots from superclass -> subclass Collections.reverse(slots); return slots.toArray(new ClassDataSlot[slots.size()]); } /** * Returns aggregate size (in bytes) of marshalled primitive field values * for represented class. */ int getPrimDataSize() { return primDataSize; } /** * Returns number of non-primitive serializable fields of represented * class. */ int getNumObjFields() { return numObjFields; } /** * Fetches the serializable primitive field values of object obj and * marshals them into byte array buf starting at offset 0. It is the * responsibility of the caller to ensure that obj is of the proper type if * non-null. */ void getPrimFieldValues(Object obj, byte[] buf) { fieldRefl.getPrimFieldValues(obj, buf); } /** * Sets the serializable primitive fields of object obj using values * unmarshalled from byte array buf starting at offset 0. It is the * responsibility of the caller to ensure that obj is of the proper type if * non-null. */ void setPrimFieldValues(Object obj, byte[] buf) { fieldRefl.setPrimFieldValues(obj, buf); } /** * Fetches the serializable object field values of object obj and stores * them in array vals starting at offset 0. It is the responsibility of * the caller to ensure that obj is of the proper type if non-null. */ void getObjFieldValues(Object obj, Object[] vals) { fieldRefl.getObjFieldValues(obj, vals); } /** * Checks that the given values, from array vals starting at offset 0, * are assignable to the given serializable object fields. * @throws ClassCastException if any value is not assignable */ void checkObjFieldValueTypes(Object obj, Object[] vals) { fieldRefl.checkObjectFieldValueTypes(obj, vals); } /** * Sets the serializable object fields of object obj using values from * array vals starting at offset 0. It is the responsibility of the caller * to ensure that obj is of the proper type if non-null. */ void setObjFieldValues(Object obj, Object[] vals) { fieldRefl.setObjFieldValues(obj, vals); } /** * Calculates and sets serializable field offsets, as well as primitive * data size and object field count totals. Throws InvalidClassException * if fields are illegally ordered. */ private void computeFieldOffsets() throws InvalidClassException { primDataSize = 0; numObjFields = 0; int firstObjIndex = -1; for (int i = 0; i < fields.length; i++) { ObjectStreamField f = fields[i]; switch (f.getTypeCode()) { case 'Z': case 'B': f.setOffset(primDataSize++); break; case 'C': case 'S': f.setOffset(primDataSize); primDataSize += 2; break; case 'I': case 'F': f.setOffset(primDataSize); primDataSize += 4; break; case 'J': case 'D': f.setOffset(primDataSize); primDataSize += 8; break; case '[': case 'L': f.setOffset(numObjFields++); if (firstObjIndex == -1) { firstObjIndex = i; } break; default: throw new InternalError(); } } if (firstObjIndex != -1 && firstObjIndex + numObjFields != fields.length) { throw new InvalidClassException(name, "illegal field order"); } } /** * If given class is the same as the class associated with this class * descriptor, returns reference to this class descriptor. Otherwise, * returns variant of this class descriptor bound to given class. */ private ObjectStreamClass getVariantFor(Class<?> cl) throws InvalidClassException { if (this.cl == cl) { return this; } ObjectStreamClass desc = new ObjectStreamClass(); if (isProxy) { desc.initProxy(cl, null, superDesc); } else { desc.initNonProxy(this, cl, null, superDesc); } return desc; } /** * Returns public no-arg constructor of given class, or null if none found. * Access checks are disabled on the returned constructor (if any), since * the defining class may still be non-public. */ private static Constructor<?> getExternalizableConstructor(Class<?> cl) { try { Constructor<?> cons = cl.getDeclaredConstructor((Class<?>[]) null); cons.setAccessible(true); return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ? cons : null; } catch (NoSuchMethodException ex) { return null; } } /** * Returns subclass-accessible no-arg constructor of first non-serializable * superclass, or null if none found. Access checks are disabled on the * returned constructor (if any). */ private static Constructor<?> getSerializableConstructor(Class<?> cl) { return reflFactory.newConstructorForSerialization(cl); } /** * Returns non-static, non-abstract method with given signature provided it * is defined by or accessible (via inheritance) by the given class, or * null if no match found. Access checks are disabled on the returned * method (if any). */ private static Method getInheritableMethod(Class<?> cl, String name, Class<?>[] argTypes, Class<?> returnType) { Method meth = null; Class<?> defCl = cl; while (defCl != null) { try { meth = defCl.getDeclaredMethod(name, argTypes); break; } catch (NoSuchMethodException ex) { defCl = defCl.getSuperclass(); } } if ((meth == null) || (meth.getReturnType() != returnType)) { return null; } meth.setAccessible(true); int mods = meth.getModifiers(); if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) { return null; } else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) { return meth; } else if ((mods & Modifier.PRIVATE) != 0) { return (cl == defCl) ? meth : null; } else { return packageEquals(cl, defCl) ? meth : null; } } /** * Returns non-static private method with given signature defined by given * class, or null if none found. Access checks are disabled on the * returned method (if any). */ private static Method getPrivateMethod(Class<?> cl, String name, Class<?>[] argTypes, Class<?> returnType) { try { Method meth = cl.getDeclaredMethod(name, argTypes); meth.setAccessible(true); int mods = meth.getModifiers(); return ((meth.getReturnType() == returnType) && ((mods & Modifier.STATIC) == 0) && ((mods & Modifier.PRIVATE) != 0)) ? meth : null; } catch (NoSuchMethodException ex) { return null; } } /** * Returns true if classes are defined in the same runtime package, false * otherwise. */ private static boolean packageEquals(Class<?> cl1, Class<?> cl2) { return (cl1.getClassLoader() == cl2.getClassLoader() && cl1.getPackageName().equals(cl2.getPackageName())); } /** * Compares class names for equality, ignoring package names. Returns true * if class names equal, false otherwise. */ private static boolean classNamesEqual(String name1, String name2) { int idx1 = name1.lastIndexOf('.') + 1; int idx2 = name2.lastIndexOf('.') + 1; int len1 = name1.length() - idx1; int len2 = name2.length() - idx2; return len1 == len2 && name1.regionMatches(idx1, name2, idx2, len1); } /** * Returns JVM type signature for given list of parameters and return type. */ private static String getMethodSignature(Class<?>[] paramTypes, Class<?> retType) { StringBuilder sb = new StringBuilder(); sb.append('('); for (int i = 0; i < paramTypes.length; i++) { appendClassSignature(sb, paramTypes[i]); } sb.append(')'); appendClassSignature(sb, retType); return sb.toString(); } /** * Convenience method for throwing an exception that is either a * RuntimeException, Error, or of some unexpected type (in which case it is * wrapped inside an IOException). */ private static void throwMiscException(Throwable th) throws IOException { if (th instanceof RuntimeException) { throw (RuntimeException) th; } else if (th instanceof Error) { throw (Error) th; } else { IOException ex = new IOException("unexpected exception type"); ex.initCause(th); throw ex; } } /** * Returns ObjectStreamField array describing the serializable fields of * the given class. Serializable fields backed by an actual field of the * class are represented by ObjectStreamFields with corresponding non-null * Field objects. Throws InvalidClassException if the (explicitly * declared) serializable fields are invalid. */ private static ObjectStreamField[] getSerialFields(Class<?> cl) throws InvalidClassException { ObjectStreamField[] fields; if (Serializable.class.isAssignableFrom(cl) && !Externalizable.class.isAssignableFrom(cl) && !Proxy.isProxyClass(cl) && !cl.isInterface()) { if ((fields = getDeclaredSerialFields(cl)) == null) { fields = getDefaultSerialFields(cl); } Arrays.sort(fields); } else { fields = NO_FIELDS; } return fields; } /** * Returns serializable fields of given class as defined explicitly by a * "serialPersistentFields" field, or null if no appropriate * "serialPersistentFields" field is defined. Serializable fields backed * by an actual field of the class are represented by ObjectStreamFields * with corresponding non-null Field objects. For compatibility with past * releases, a "serialPersistentFields" field with a null value is * considered equivalent to not declaring "serialPersistentFields". Throws * InvalidClassException if the declared serializable fields are * invalid--e.g., if multiple fields share the same name. */ private static ObjectStreamField[] getDeclaredSerialFields(Class<?> cl) throws InvalidClassException { ObjectStreamField[] serialPersistentFields = null; try { Field f = cl.getDeclaredField("serialPersistentFields"); int mask = Modifier.PRIVATE | Modifier.STATIC | Modifier.FINAL; if ((f.getModifiers() & mask) == mask) { f.setAccessible(true); serialPersistentFields = (ObjectStreamField[]) f.get(null); } } catch (Exception ex) { } if (serialPersistentFields == null) { return null; } else if (serialPersistentFields.length == 0) { return NO_FIELDS; } ObjectStreamField[] boundFields = new ObjectStreamField[serialPersistentFields.length]; Set<String> fieldNames = new HashSet<>(serialPersistentFields.length); for (int i = 0; i < serialPersistentFields.length; i++) { ObjectStreamField spf = serialPersistentFields[i]; String fname = spf.getName(); if (fieldNames.contains(fname)) { throw new InvalidClassException("multiple serializable fields named " + fname); } fieldNames.add(fname); try { Field f = cl.getDeclaredField(fname); if ((f.getType() == spf.getType()) && ((f.getModifiers() & Modifier.STATIC) == 0)) { boundFields[i] = new ObjectStreamField(f, spf.isUnshared(), true); } } catch (NoSuchFieldException ex) { } if (boundFields[i] == null) { boundFields[i] = new ObjectStreamField(fname, spf.getType(), spf.isUnshared()); } } return boundFields; } /** * Returns array of ObjectStreamFields corresponding to all non-static * non-transient fields declared by given class. Each ObjectStreamField * contains a Field object for the field it represents. If no default * serializable fields exist, NO_FIELDS is returned. */ private static ObjectStreamField[] getDefaultSerialFields(Class<?> cl) { Field[] clFields = cl.getDeclaredFields(); ArrayList<ObjectStreamField> list = new ArrayList<>(); int mask = Modifier.STATIC | Modifier.TRANSIENT; for (int i = 0; i < clFields.length; i++) { if ((clFields[i].getModifiers() & mask) == 0) { list.add(new ObjectStreamField(clFields[i], false, true)); } } int size = list.size(); return (size == 0) ? NO_FIELDS : list.toArray(new ObjectStreamField[size]); } /** * Returns explicit serial version UID value declared by given class, or * null if none. */ private static Long getDeclaredSUID(Class<?> cl) { try { Field f = cl.getDeclaredField("serialVersionUID"); int mask = Modifier.STATIC | Modifier.FINAL; if ((f.getModifiers() & mask) == mask) { f.setAccessible(true); return Long.valueOf(f.getLong(null)); } } catch (Exception ex) { } return null; } /** * Computes the default serial version UID value for the given class. */ private static long computeDefaultSUID(Class<?> cl) { if (!Serializable.class.isAssignableFrom(cl) || Proxy.isProxyClass(cl)) { return 0L; } try { ByteArrayOutputStream bout = new ByteArrayOutputStream(); DataOutputStream dout = new DataOutputStream(bout); dout.writeUTF(cl.getName()); int classMods = cl.getModifiers() & (Modifier.PUBLIC | Modifier.FINAL | Modifier.INTERFACE | Modifier.ABSTRACT); /* * compensate for javac bug in which ABSTRACT bit was set for an * interface only if the interface declared methods */ Method[] methods = cl.getDeclaredMethods(); if ((classMods & Modifier.INTERFACE) != 0) { classMods = (methods.length > 0) ? (classMods | Modifier.ABSTRACT) : (classMods & ~Modifier.ABSTRACT); } dout.writeInt(classMods); if (!cl.isArray()) { /* * compensate for change in 1.2FCS in which * Class.getInterfaces() was modified to return Cloneable and * Serializable for array classes. */ Class<?>[] interfaces = cl.getInterfaces(); String[] ifaceNames = new String[interfaces.length]; for (int i = 0; i < interfaces.length; i++) { ifaceNames[i] = interfaces[i].getName(); } Arrays.sort(ifaceNames); for (int i = 0; i < ifaceNames.length; i++) { dout.writeUTF(ifaceNames[i]); } } Field[] fields = cl.getDeclaredFields(); MemberSignature[] fieldSigs = new MemberSignature[fields.length]; for (int i = 0; i < fields.length; i++) { fieldSigs[i] = new MemberSignature(fields[i]); } Arrays.sort(fieldSigs, new Comparator<>() { public int compare(MemberSignature ms1, MemberSignature ms2) { return ms1.name.compareTo(ms2.name); } }); for (int i = 0; i < fieldSigs.length; i++) { MemberSignature sig = fieldSigs[i]; int mods = sig.member.getModifiers() & (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED | Modifier.STATIC | Modifier.FINAL | Modifier.VOLATILE | Modifier.TRANSIENT); if (((mods & Modifier.PRIVATE) == 0) || ((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0)) { dout.writeUTF(sig.name); dout.writeInt(mods); dout.writeUTF(sig.signature); } } if (hasStaticInitializer(cl)) { dout.writeUTF("<clinit>"); dout.writeInt(Modifier.STATIC); dout.writeUTF("()V"); } Constructor<?>[] cons = cl.getDeclaredConstructors(); MemberSignature[] consSigs = new MemberSignature[cons.length]; for (int i = 0; i < cons.length; i++) { consSigs[i] = new MemberSignature(cons[i]); } Arrays.sort(consSigs, new Comparator<>() { public int compare(MemberSignature ms1, MemberSignature ms2) { return ms1.signature.compareTo(ms2.signature); } }); for (int i = 0; i < consSigs.length; i++) { MemberSignature sig = consSigs[i]; int mods = sig.member.getModifiers() & (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED | Modifier.STATIC | Modifier.FINAL | Modifier.SYNCHRONIZED | Modifier.NATIVE | Modifier.ABSTRACT | Modifier.STRICT); if ((mods & Modifier.PRIVATE) == 0) { dout.writeUTF("<init>"); dout.writeInt(mods); dout.writeUTF(sig.signature.replace('/', '.')); } } MemberSignature[] methSigs = new MemberSignature[methods.length]; for (int i = 0; i < methods.length; i++) { methSigs[i] = new MemberSignature(methods[i]); } Arrays.sort(methSigs, new Comparator<>() { public int compare(MemberSignature ms1, MemberSignature ms2) { int comp = ms1.name.compareTo(ms2.name); if (comp == 0) { comp = ms1.signature.compareTo(ms2.signature); } return comp; } }); for (int i = 0; i < methSigs.length; i++) { MemberSignature sig = methSigs[i]; int mods = sig.member.getModifiers() & (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED | Modifier.STATIC | Modifier.FINAL | Modifier.SYNCHRONIZED | Modifier.NATIVE | Modifier.ABSTRACT | Modifier.STRICT); if ((mods & Modifier.PRIVATE) == 0) { dout.writeUTF(sig.name); dout.writeInt(mods); dout.writeUTF(sig.signature.replace('/', '.')); } } dout.flush(); MessageDigest md = MessageDigest.getInstance("SHA"); byte[] hashBytes = md.digest(bout.toByteArray()); long hash = 0; for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) { hash = (hash << 8) | (hashBytes[i] & 0xFF); } return hash; } catch (IOException ex) { throw new InternalError(ex); } catch (NoSuchAlgorithmException ex) { throw new SecurityException(ex.getMessage()); } } /** * Returns true if the given class defines a static initializer method, * false otherwise. */ private static native boolean hasStaticInitializer(Class<?> cl); /** * Class for computing and caching field/constructor/method signatures * during serialVersionUID calculation. */ private static class MemberSignature { public final Member member; public final String name; public final String signature; public MemberSignature(Field field) { member = field; name = field.getName(); signature = getClassSignature(field.getType()); } public MemberSignature(Constructor<?> cons) { member = cons; name = cons.getName(); signature = getMethodSignature(cons.getParameterTypes(), Void.TYPE); } public MemberSignature(Method meth) { member = meth; name = meth.getName(); signature = getMethodSignature(meth.getParameterTypes(), meth.getReturnType()); } } /** * Class for setting and retrieving serializable field values in batch. */ // REMIND: dynamically generate these? private static class FieldReflector { /** handle for performing unsafe operations */ private static final Unsafe unsafe = Unsafe.getUnsafe(); /** fields to operate on */ private final ObjectStreamField[] fields; /** number of primitive fields */ private final int numPrimFields; /** unsafe field keys for reading fields - may contain dupes */ private final long[] readKeys; /** unsafe fields keys for writing fields - no dupes */ private final long[] writeKeys; /** field data offsets */ private final int[] offsets; /** field type codes */ private final char[] typeCodes; /** field types */ private final Class<?>[] types; /** * Constructs FieldReflector capable of setting/getting values from the * subset of fields whose ObjectStreamFields contain non-null * reflective Field objects. ObjectStreamFields with null Fields are * treated as filler, for which get operations return default values * and set operations discard given values. */ FieldReflector(ObjectStreamField[] fields) { this.fields = fields; int nfields = fields.length; readKeys = new long[nfields]; writeKeys = new long[nfields]; offsets = new int[nfields]; typeCodes = new char[nfields]; ArrayList<Class<?>> typeList = new ArrayList<>(); Set<Long> usedKeys = new HashSet<>(); for (int i = 0; i < nfields; i++) { ObjectStreamField f = fields[i]; Field rf = f.getField(); long key = (rf != null) ? unsafe.objectFieldOffset(rf) : Unsafe.INVALID_FIELD_OFFSET; readKeys[i] = key; writeKeys[i] = usedKeys.add(key) ? key : Unsafe.INVALID_FIELD_OFFSET; offsets[i] = f.getOffset(); typeCodes[i] = f.getTypeCode(); if (!f.isPrimitive()) { typeList.add((rf != null) ? rf.getType() : null); } } types = typeList.toArray(new Class<?>[typeList.size()]); numPrimFields = nfields - types.length; } /** * Returns list of ObjectStreamFields representing fields operated on * by this reflector. The shared/unshared values and Field objects * contained by ObjectStreamFields in the list reflect their bindings * to locally defined serializable fields. */ ObjectStreamField[] getFields() { return fields; } /** * Fetches the serializable primitive field values of object obj and * marshals them into byte array buf starting at offset 0. The caller * is responsible for ensuring that obj is of the proper type. */ void getPrimFieldValues(Object obj, byte[] buf) { if (obj == null) { throw new NullPointerException(); } /* assuming checkDefaultSerialize() has been called on the class * descriptor this FieldReflector was obtained from, no field keys * in array should be equal to Unsafe.INVALID_FIELD_OFFSET. */ for (int i = 0; i < numPrimFields; i++) { long key = readKeys[i]; int off = offsets[i]; switch (typeCodes[i]) { case 'Z': Bits.putBoolean(buf, off, unsafe.getBoolean(obj, key)); break; case 'B': buf[off] = unsafe.getByte(obj, key); break; case 'C': Bits.putChar(buf, off, unsafe.getChar(obj, key)); break; case 'S': Bits.putShort(buf, off, unsafe.getShort(obj, key)); break; case 'I': Bits.putInt(buf, off, unsafe.getInt(obj, key)); break; case 'F': Bits.putFloat(buf, off, unsafe.getFloat(obj, key)); break; case 'J': Bits.putLong(buf, off, unsafe.getLong(obj, key)); break; case 'D': Bits.putDouble(buf, off, unsafe.getDouble(obj, key)); break; default: throw new InternalError(); } } } /** * Sets the serializable primitive fields of object obj using values * unmarshalled from byte array buf starting at offset 0. The caller * is responsible for ensuring that obj is of the proper type. */ void setPrimFieldValues(Object obj, byte[] buf) { if (obj == null) { throw new NullPointerException(); } for (int i = 0; i < numPrimFields; i++) { long key = writeKeys[i]; if (key == Unsafe.INVALID_FIELD_OFFSET) { continue; // discard value } int off = offsets[i]; switch (typeCodes[i]) { case 'Z': unsafe.putBoolean(obj, key, Bits.getBoolean(buf, off)); break; case 'B': unsafe.putByte(obj, key, buf[off]); break; case 'C': unsafe.putChar(obj, key, Bits.getChar(buf, off)); break; case 'S': unsafe.putShort(obj, key, Bits.getShort(buf, off)); break; case 'I': unsafe.putInt(obj, key, Bits.getInt(buf, off)); break; case 'F': unsafe.putFloat(obj, key, Bits.getFloat(buf, off)); break; case 'J': unsafe.putLong(obj, key, Bits.getLong(buf, off)); break; case 'D': unsafe.putDouble(obj, key, Bits.getDouble(buf, off)); break; default: throw new InternalError(); } } } /** * Fetches the serializable object field values of object obj and * stores them in array vals starting at offset 0. The caller is * responsible for ensuring that obj is of the proper type. */ void getObjFieldValues(Object obj, Object[] vals) { if (obj == null) { throw new NullPointerException(); } /* assuming checkDefaultSerialize() has been called on the class * descriptor this FieldReflector was obtained from, no field keys * in array should be equal to Unsafe.INVALID_FIELD_OFFSET. */ for (int i = numPrimFields; i < fields.length; i++) { switch (typeCodes[i]) { case 'L': case '[': vals[offsets[i]] = unsafe.getReference(obj, readKeys[i]); break; default: throw new InternalError(); } } } /** * Checks that the given values, from array vals starting at offset 0, * are assignable to the given serializable object fields. * @throws ClassCastException if any value is not assignable */ void checkObjectFieldValueTypes(Object obj, Object[] vals) { setObjFieldValues(obj, vals, true); } /** * Sets the serializable object fields of object obj using values from * array vals starting at offset 0. The caller is responsible for * ensuring that obj is of the proper type; however, attempts to set a * field with a value of the wrong type will trigger an appropriate * ClassCastException. */ void setObjFieldValues(Object obj, Object[] vals) { setObjFieldValues(obj, vals, false); } private void setObjFieldValues(Object obj, Object[] vals, boolean dryRun) { if (obj == null) { throw new NullPointerException(); } for (int i = numPrimFields; i < fields.length; i++) { long key = writeKeys[i]; if (key == Unsafe.INVALID_FIELD_OFFSET) { continue; // discard value } switch (typeCodes[i]) { case 'L': case '[': Object val = vals[offsets[i]]; if (val != null && !types[i - numPrimFields].isInstance(val)) { Field f = fields[i].getField(); throw new ClassCastException("cannot assign instance of " + val.getClass().getName() + " to field " + f.getDeclaringClass().getName() + "." + f.getName() + " of type " + f.getType().getName() + " in instance of " + obj.getClass().getName()); } if (!dryRun) unsafe.putReference(obj, key, val); break; default: throw new InternalError(); } } } } /** * Matches given set of serializable fields with serializable fields * described by the given local class descriptor, and returns a * FieldReflector instance capable of setting/getting values from the * subset of fields that match (non-matching fields are treated as filler, * for which get operations return default values and set operations * discard given values). Throws InvalidClassException if unresolvable * type conflicts exist between the two sets of fields. */ private static FieldReflector getReflector(ObjectStreamField[] fields, ObjectStreamClass localDesc) throws InvalidClassException { // class irrelevant if no fields Class<?> cl = (localDesc != null && fields.length > 0) ? localDesc.cl : null; processQueue(Caches.reflectorsQueue, Caches.reflectors); FieldReflectorKey key = new FieldReflectorKey(cl, fields, Caches.reflectorsQueue); Reference<?> ref = Caches.reflectors.get(key); Object entry = null; if (ref != null) { entry = ref.get(); } EntryFuture future = null; if (entry == null) { EntryFuture newEntry = new EntryFuture(); Reference<?> newRef = new SoftReference<>(newEntry); do { if (ref != null) { Caches.reflectors.remove(key, ref); } ref = Caches.reflectors.putIfAbsent(key, newRef); if (ref != null) { entry = ref.get(); } } while (ref != null && entry == null); if (entry == null) { future = newEntry; } } if (entry instanceof FieldReflector) { // check common case first return (FieldReflector) entry; } else if (entry instanceof EntryFuture) { entry = ((EntryFuture) entry).get(); } else if (entry == null) { try { entry = new FieldReflector(matchFields(fields, localDesc)); } catch (Throwable th) { entry = th; } future.set(entry); Caches.reflectors.put(key, new SoftReference<>(entry)); } if (entry instanceof FieldReflector) { return (FieldReflector) entry; } else if (entry instanceof InvalidClassException) { throw (InvalidClassException) entry; } else if (entry instanceof RuntimeException) { throw (RuntimeException) entry; } else if (entry instanceof Error) { throw (Error) entry; } else { throw new InternalError("unexpected entry: " + entry); } } /** * FieldReflector cache lookup key. Keys are considered equal if they * refer to the same class and equivalent field formats. */ private static class FieldReflectorKey extends WeakReference<Class<?>> { private final String[] sigs; private final int hash; private final boolean nullClass; FieldReflectorKey(Class<?> cl, ObjectStreamField[] fields, ReferenceQueue<Class<?>> queue) { super(cl, queue); nullClass = (cl == null); sigs = new String[2 * fields.length]; for (int i = 0, j = 0; i < fields.length; i++) { ObjectStreamField f = fields[i]; sigs[j++] = f.getName(); sigs[j++] = f.getSignature(); } hash = System.identityHashCode(cl) + Arrays.hashCode(sigs); } public int hashCode() { return hash; } public boolean equals(Object obj) { if (obj == this) { return true; } if (obj instanceof FieldReflectorKey) { FieldReflectorKey other = (FieldReflectorKey) obj; Class<?> referent; return (nullClass ? other.nullClass : ((referent = get()) != null) && (referent == other.get())) && Arrays.equals(sigs, other.sigs); } else { return false; } } } /** * Matches given set of serializable fields with serializable fields * obtained from the given local class descriptor (which contain bindings * to reflective Field objects). Returns list of ObjectStreamFields in * which each ObjectStreamField whose signature matches that of a local * field contains a Field object for that field; unmatched * ObjectStreamFields contain null Field objects. Shared/unshared settings * of the returned ObjectStreamFields also reflect those of matched local * ObjectStreamFields. Throws InvalidClassException if unresolvable type * conflicts exist between the two sets of fields. */ private static ObjectStreamField[] matchFields(ObjectStreamField[] fields, ObjectStreamClass localDesc) throws InvalidClassException { ObjectStreamField[] localFields = (localDesc != null) ? localDesc.fields : NO_FIELDS; /* * Even if fields == localFields, we cannot simply return localFields * here. In previous implementations of serialization, * ObjectStreamField.getType() returned Object.class if the * ObjectStreamField represented a non-primitive field and belonged to * a non-local class descriptor. To preserve this (questionable) * behavior, the ObjectStreamField instances returned by matchFields * cannot report non-primitive types other than Object.class; hence * localFields cannot be returned directly. */ ObjectStreamField[] matches = new ObjectStreamField[fields.length]; for (int i = 0; i < fields.length; i++) { ObjectStreamField f = fields[i], m = null; for (int j = 0; j < localFields.length; j++) { ObjectStreamField lf = localFields[j]; if (f.getName().equals(lf.getName())) { if ((f.isPrimitive() || lf.isPrimitive()) && f.getTypeCode() != lf.getTypeCode()) { throw new InvalidClassException(localDesc.name, "incompatible types for field " + f.getName()); } if (lf.getField() != null) { m = new ObjectStreamField(lf.getField(), lf.isUnshared(), false); } else { m = new ObjectStreamField(lf.getName(), lf.getSignature(), lf.isUnshared()); } } } if (m == null) { m = new ObjectStreamField(f.getName(), f.getSignature(), false); } m.setOffset(f.getOffset()); matches[i] = m; } return matches; } /** * Removes from the specified map any keys that have been enqueued * on the specified reference queue. */ static void processQueue(ReferenceQueue<Class<?>> queue, ConcurrentMap<? extends WeakReference<Class<?>>, ?> map) { Reference<? extends Class<?>> ref; while ((ref = queue.poll()) != null) { map.remove(ref); } } /** * Weak key for Class objects. * **/ static class WeakClassKey extends WeakReference<Class<?>> { /** * saved value of the referent's identity hash code, to maintain * a consistent hash code after the referent has been cleared */ private final int hash; /** * Create a new WeakClassKey to the given object, registered * with a queue. */ WeakClassKey(Class<?> cl, ReferenceQueue<Class<?>> refQueue) { super(cl, refQueue); hash = System.identityHashCode(cl); } /** * Returns the identity hash code of the original referent. */ public int hashCode() { return hash; } /** * Returns true if the given object is this identical * WeakClassKey instance, or, if this object's referent has not * been cleared, if the given object is another WeakClassKey * instance with the identical non-null referent as this one. */ public boolean equals(Object obj) { if (obj == this) { return true; } if (obj instanceof WeakClassKey) { Object referent = get(); return (referent != null) && (referent == ((WeakClassKey) obj).get()); } else { return false; } } } }