Java tutorial
/* * Copyright 2008 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.google.gwt.user.rebind.rpc; import com.google.gwt.core.ext.TreeLogger; import com.google.gwt.core.ext.typeinfo.JArrayType; import com.google.gwt.core.ext.typeinfo.JClassType; import com.google.gwt.core.ext.typeinfo.JField; import com.google.gwt.core.ext.typeinfo.JParameterizedType; import com.google.gwt.core.ext.typeinfo.JPrimitiveType; import com.google.gwt.core.ext.typeinfo.JType; import com.google.gwt.core.ext.typeinfo.TypeOracle; import com.google.gwt.dev.util.Util; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.List; import java.util.Set; import java.util.zip.CRC32; /** * Utilities used for implementing serialization. */ public class SerializationUtils { static final Comparator<JField> FIELD_COMPARATOR = new Comparator<JField>() { public int compare(JField f1, JField f2) { return f1.getName().compareTo(f2.getName()); } }; static final String GENERATED_FIELD_SERIALIZER_SUFFIX = "_FieldSerializer"; static final String TYPE_SERIALIZER_SUFFIX = "_TypeSerializer"; static final Set<String> TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES = new HashSet<String>(); static { TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Boolean"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Byte"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Character"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Double"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Exception"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Float"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Integer"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Long"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Object"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Short"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.String"); TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("java.lang.Throwable"); /* * Work around for incompatible type hierarchy (and therefore signature) * between JUnit3 and JUnit4. */ TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES.add("junit.framework.AssertionFailedError"); } /** * Returns the binary name of a type. This is the same name that would be * returned by {@link Class#getName()} for this type. * * @param type TypeOracle type to get the name for * @return binary name for a type */ public static String getRpcTypeName(JType type) { JPrimitiveType primitiveType = type.isPrimitive(); if (primitiveType != null) { return primitiveType.getJNISignature(); } JArrayType arrayType = type.isArray(); if (arrayType != null) { JType component = arrayType.getComponentType(); if (component.isClassOrInterface() != null) { return "[L" + getRpcTypeName(arrayType.getComponentType()) + ";"; } else { return "[" + getRpcTypeName(arrayType.getComponentType()); } } JParameterizedType parameterizedType = type.isParameterized(); if (parameterizedType != null) { return getRpcTypeName(parameterizedType.getBaseType()); } JClassType classType = type.isClassOrInterface(); assert (classType != null); JClassType enclosingType = classType.getEnclosingType(); if (enclosingType != null) { return getRpcTypeName(enclosingType) + "$" + classType.getSimpleSourceName(); } return classType.getQualifiedSourceName(); } /** * Returns the set of fields that are serializable for a given class type. * This method does not consider any superclass fields. * * @param typeOracle the type oracle * @param classType the class for which we want serializable fields * @return array of fields that meet the serialization criteria */ public static JField[] getSerializableFields(TypeOracle typeOracle, JClassType classType) { assert (classType != null); List<JField> fields = new ArrayList<JField>(); JField[] declFields = classType.getFields(); assert (declFields != null); for (JField field : declFields) { if (SerializableTypeOracleBuilder.shouldConsiderForSerialization(TreeLogger.NULL, true, field)) { fields.add(field); } } Collections.sort(fields, FIELD_COMPARATOR); return fields.toArray(new JField[fields.size()]); } /** * Returns the name of the field serializer for a particular type. This name * can be either the name of a custom field serializer or that of a generated * field serializer. If the type is not serializable then it can return null. * * @param type the type that is going to be serialized * @return the fully qualified name of the field serializer for the given type */ static String getFieldSerializerName(TypeOracle typeOracle, JType type) { JClassType customSerializer = SerializableTypeOracleBuilder.findCustomFieldSerializer(typeOracle, type); if (customSerializer != null) { return customSerializer.getQualifiedSourceName(); } assert (type.isClassOrInterface() != null || type.isArray() != null); JClassType classType = (JClassType) type; return getStandardSerializerName(classType); } /** * Returns the serialization signature for a type. * * @param instanceType * @return a string representing the serialization signature of a type */ static String getSerializationSignature(TypeOracle typeOracle, JType type) throws RuntimeException { CRC32 crc = new CRC32(); try { generateSerializationSignature(typeOracle, type, crc); } catch (UnsupportedEncodingException e) { throw new RuntimeException("Could not compute the serialization signature", e); } return Long.toString(crc.getValue()); } /** * Returns the name of the generated field serializer. */ static String getStandardSerializerName(JClassType classType) { String[] name = Shared.synthesizeTopLevelClassName(classType, SerializationUtils.GENERATED_FIELD_SERIALIZER_SUFFIX); if (name[0].length() > 0) { String serializerName = name[0] + "." + name[1]; if (SerializableTypeOracleBuilder.isInStandardJavaPackage(classType.getQualifiedSourceName())) { /* * Don't generate code into java packages. If you do Development Mode * CompilingClassLoader will fail to resolve references to the generated * code. */ serializerName = "com.google.gwt.user.client.rpc.core." + serializerName; } return serializerName; } else { return name[1]; } } /** * Returns the qualified name of the type serializer class for the given * service interface. * * @param serviceIntf service interface * @return name of the type serializer that handles the service interface */ static String getTypeSerializerQualifiedName(JClassType serviceIntf) throws IllegalArgumentException { if (serviceIntf.isInterface() == null) { throw new IllegalArgumentException( serviceIntf.getQualifiedSourceName() + " is not a service interface"); } String[] name = Shared.synthesizeTopLevelClassName(serviceIntf, TYPE_SERIALIZER_SUFFIX); if (name[0].length() > 0) { return name[0] + "." + name[1]; } else { return name[1]; } } /** * Returns the simple name of the type serializer class for the given service * interface. * * @param serviceIntf service interface * @return the simple name of the type serializer class */ static String getTypeSerializerSimpleName(JClassType serviceIntf) throws IllegalArgumentException { if (serviceIntf.isInterface() == null) { throw new IllegalArgumentException( serviceIntf.getQualifiedSourceName() + " is not a service interface"); } String[] name = Shared.synthesizeTopLevelClassName(serviceIntf, TYPE_SERIALIZER_SUFFIX); return name[1]; } private static boolean excludeImplementationFromSerializationSignature(JType instanceType) { if (TYPES_WHOSE_IMPLEMENTATION_IS_EXCLUDED_FROM_SIGNATURES .contains(instanceType.getQualifiedSourceName())) { return true; } return false; } private static void generateSerializationSignature(TypeOracle typeOracle, JType type, CRC32 crc) throws UnsupportedEncodingException { JParameterizedType parameterizedType = type.isParameterized(); if (parameterizedType != null) { generateSerializationSignature(typeOracle, parameterizedType.getRawType(), crc); return; } String serializedTypeName = getRpcTypeName(type); crc.update(serializedTypeName.getBytes(Util.DEFAULT_ENCODING)); if (excludeImplementationFromSerializationSignature(type)) { return; } JClassType customSerializer = SerializableTypeOracleBuilder.findCustomFieldSerializer(typeOracle, type); if (customSerializer != null) { generateSerializationSignature(typeOracle, customSerializer, crc); } else if (type.isArray() != null) { JArrayType isArray = type.isArray(); generateSerializationSignature(typeOracle, isArray.getComponentType(), crc); } else if (type.isClassOrInterface() != null) { JClassType isClassOrInterface = type.isClassOrInterface(); JField[] fields = getSerializableFields(typeOracle, isClassOrInterface); for (JField field : fields) { assert (field != null); crc.update(field.getName().getBytes(Util.DEFAULT_ENCODING)); crc.update(getRpcTypeName(field.getType()).getBytes(Util.DEFAULT_ENCODING)); } JClassType superClass = isClassOrInterface.getSuperclass(); if (superClass != null) { generateSerializationSignature(typeOracle, superClass, crc); } } } }