Java tutorial
/** * Copyright 2014 Steve Hannah * * 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 ca.weblite.asm; import com.sun.source.tree.ClassTree; import com.sun.source.tree.CompilationUnitTree; import com.sun.source.tree.ImportTree; import com.sun.source.tree.MethodTree; import com.sun.source.tree.Tree; import com.sun.source.tree.TypeParameterTree; import com.sun.source.tree.VariableTree; import com.sun.source.util.JavacTask; import com.sun.source.util.TreePathScanner; import com.sun.tools.javac.api.JavacTool; import java.io.BufferedReader; import java.io.File; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.nio.file.DirectoryStream; import java.nio.file.Files; import java.nio.file.Path; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import javax.lang.model.element.Modifier; import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.SimpleJavaFileObject; import org.objectweb.asm.ClassWriter; import org.objectweb.asm.Opcodes; import org.objectweb.asm.Type; import org.objectweb.asm.tree.ClassNode; /** * * @author shannah */ public class JavaExtendedStubCompiler { byte[] output; private Context context; public JavaExtendedStubCompiler(Context context) { this.context = context; } /** * Wrapper for java file object so that it can be read by the TreeScanner * */ private static class MyFileObject extends SimpleJavaFileObject { private String src; public MyFileObject(File file) throws IOException { super(file.toURI(), JavaFileObject.Kind.SOURCE); src = readFile(file.getPath()); } private String readFile(String file) throws IOException { BufferedReader reader = new BufferedReader(new FileReader(file)); String line = null; StringBuilder stringBuilder = new StringBuilder(); String ls = System.getProperty("line.separator"); while ((line = reader.readLine()) != null) { stringBuilder.append(line); stringBuilder.append(ls); } return stringBuilder.toString(); } @Override public CharSequence getCharContent(boolean ignoreEncodingErrors) { return src; } } public List<Type> extractTypes(File sourceFile) throws IOException { JavaCompiler compiler = JavacTool.create(); MyFileObject[] fos = new MyFileObject[] { new MyFileObject(sourceFile) }; JavacTask task = (JavacTask) compiler.getTask(null, null, null, null, null, Arrays.asList(fos)); Iterable<? extends CompilationUnitTree> asts = task.parse(); TreePathScanner scanner; final List<Type> types = new ArrayList<Type>(); scanner = new TreePathScanner() { String packageName = ""; String currPath = ""; @Override public Object visitClass(ClassTree ct, Object p) { if (currPath.equals(packageName)) { currPath = currPath.length() > 0 ? currPath + "/" + ct.getSimpleName().toString() : ct.getSimpleName().toString(); } else { currPath = currPath + "$" + ct.getSimpleName().toString(); } types.add(Type.getObjectType(currPath)); Object out = super.visitClass(ct, p); int lastSlash = currPath.lastIndexOf("/"); int lastDollar = currPath.lastIndexOf("$"); int lastPos = Math.max(lastSlash, lastDollar); currPath = lastPos != -1 ? currPath.substring(0, lastPos) : ""; return out; } @Override public Object visitCompilationUnit(CompilationUnitTree cut, Object p) { packageName = cut.getPackageName().toString(); currPath = packageName.replaceAll("\\.", "/"); return super.visitCompilationUnit(cut, p); } }; scanner.scan(asts, null); return types; } public void compileFile(File sourceFile, File sourceRoot, File destinationDirectory) throws IOException { String relativePath = sourceFile.getPath().substring(sourceRoot.getPath().length()); String relativeBase = relativePath; int lastDot = relativePath.lastIndexOf("."); if (lastDot != -1) { relativeBase = relativeBase.substring(0, lastDot); } String relativeClassFilePath = relativeBase + ".class"; File classFile = new File(destinationDirectory, relativeClassFilePath); if (classFile.lastModified() >= sourceFile.lastModified()) { // The class file hasn't been changed. return; } Map<String, byte[]> result = compile((List) null, sourceFile); for (Map.Entry<String, byte[]> e : result.entrySet()) { File output = new File(destinationDirectory, e.getKey() + ".class"); if (output.lastModified() < sourceFile.lastModified()) { output.getParentFile().mkdirs(); try (FileOutputStream fos = new FileOutputStream(output)) { fos.write(e.getValue()); } } } } public void compileDirectory(File sourceDirectory, File sourceRoot, File destinationDirectory, boolean recursive) throws IOException { compileDirectory(sourceDirectory, sourceRoot, destinationDirectory, recursive, false); } private void compileDirectory(File sourceDirectory, File sourceRoot, File destinationDirectory, boolean recursive, boolean skipDirectoryCheck) throws IOException { if (!skipDirectoryCheck && !sourceDirectory.isDirectory()) { return; } try (DirectoryStream<Path> ds = Files.newDirectoryStream(sourceDirectory.toPath())) { for (Path p : ds) { //System.out.println("Path "+p); if (p.toFile().getName().endsWith(".java")) { compileFile(p.toFile(), sourceRoot, destinationDirectory); } else if (recursive && p.toFile().isDirectory()) { compileDirectory(p.toFile(), sourceRoot, destinationDirectory, recursive, true); } } } } private class ClassInfo { int numConstructors = 0; } public Map<String, byte[]> compile(List<Type> types, File sourceFile) throws IOException { final Map<String, byte[]> outMap = new HashMap<>(); final Set<String> typeNames = (types == null) ? null : new HashSet<String>(); if (types != null) { for (Type type : types) { typeNames.add(type.getInternalName()); } } JavaCompiler compiler = JavacTool.create(); MyFileObject[] fos = new MyFileObject[] { new MyFileObject(sourceFile) }; JavacTask task = (JavacTask) compiler.getTask(null, null, null, null, null, Arrays.asList(fos)); Iterable<? extends CompilationUnitTree> asts = task.parse(); TreePathScanner scanner; final LinkedList<ClassFinder> scopeStack = new LinkedList<>(); scanner = new TreePathScanner() { String packageName; ClassNode superClass; LinkedList<String> stack = new LinkedList<>(); LinkedList<ClassInfo> classInfoStack = new LinkedList<>(); LinkedList<ClassWriter> cwStack = new LinkedList<>(); LinkedList<List<? extends TypeParameterTree>> typeParametersStack = new LinkedList<>(); @Override public Object visitCompilationUnit(CompilationUnitTree cut, Object p) { packageName = cut.getPackageName().toString(); ClassFinder scope = new ClassFinder(context.get(ClassLoader.class), null); scopeStack.push(scope); scope.addImport(packageName + ".*"); return super.visitCompilationUnit(cut, p); } private String getThisInternalName(String simpleName) { simpleName = simpleName.replaceAll("\\.", "$"); StringBuilder sb = new StringBuilder(); Iterator<String> it = stack.descendingIterator(); sb.append(packageName.replaceAll("\\.", "/")); sb.append("/"); while (it.hasNext()) { sb.append(it.next()).append("$"); } sb.append(simpleName); return sb.toString(); } @Override public Object visitImport(ImportTree it, Object p) { if (!it.isStatic()) { String path = it.getQualifiedIdentifier().toString(); scopeStack.peek().addImport(path); } return super.visitImport(it, p); } Object visitConstructor(final MethodTree mt, Object p) { ClassWriter classWriter = cwStack.peek(); List<Type> argTypes = new ArrayList<Type>(); boolean isVarArgs = false; for (VariableTree v : mt.getParameters()) { if (v.toString().endsWith("... " + v.getName())) { isVarArgs = true; } String type = v.getType().toString(); String fullType = type; String signature = null; try { signature = TypeUtil.getTypeSignature(type, scopeStack.peek()); } catch (Throwable t) { System.out.println("Failed to find signature for type"); } if (type.indexOf("<") != -1) { type = type.substring(0, type.indexOf("<")); } int dim = 0; if (TypeUtil.isArrayType(type)) { dim = TypeUtil.getArrayTypeDimension(type); type = TypeUtil.getArrayElementType(type); } if (TypeUtil.isPrimitiveType(type)) { String descriptor = TypeUtil.getDescriptor(type); argTypes.add(Type.getType(TypeUtil.getArrayDescriptor(descriptor, dim))); } else { ClassNode stub = scopeStack.peek().findStub(type); assert stub != null; argTypes.add(Type.getObjectType(stub.name)); } } String methodDescriptor = null; String methodSignature = null; if (argTypes.isEmpty()) { methodDescriptor = Type.getMethodDescriptor(Type.getType("V")); } else { methodDescriptor = Type.getMethodDescriptor(Type.getType("V"), argTypes.toArray(new Type[0])); } int flags = getFlags(mt.getModifiers().getFlags()); if (isVarArgs) { flags |= Opcodes.ACC_VARARGS; } classWriter.visitMethod(flags, mt.getName().toString(), methodDescriptor, null, null); classInfoStack.peek().numConstructors++; return null; } @Override public Object visitMethod(MethodTree mt, Object p) { if (mt.getReturnType() == null) { // It's a constructor return visitConstructor(mt, p); } else { boolean isVarArgs = false; ClassWriter classWriter = cwStack.peek(); List<Type> argTypes = new ArrayList<>(); List<String> sigArgTypes = new ArrayList<>(); for (VariableTree v : mt.getParameters()) { String type = v.getType().toString(); if (v.toString().endsWith("... " + v.getName())) { isVarArgs = true; } sigArgTypes.add(type); int dim = 0; if (TypeUtil.isArrayType(type)) { dim = TypeUtil.getArrayTypeDimension(type); type = TypeUtil.getArrayElementType(type); } if (TypeUtil.isPrimitiveType(type)) { String descriptor = TypeUtil.getDescriptor(type); argTypes.add(Type.getType(TypeUtil.getArrayDescriptor(descriptor, dim))); } else { if (isGenericType(type)) { type = "Object"; } int arrowPos = type.indexOf("<"); if (arrowPos != -1) { type = type.substring(0, arrowPos); } ClassNode stub = scopeStack.peek().findStub(type); if (stub == null) { throw new RuntimeException("Could not find class for " + type); } Type argType = Type.getObjectType(stub.name); argType = Type.getType(TypeUtil.getArrayDescriptor(argType.getInternalName(), dim)); argTypes.add(argType); } } String returnType = mt.getReturnType().toString(); if (isGenericType(returnType)) { returnType = "Object"; } String methodSignature = null; try { methodSignature = TypeUtil.getMethodSignature(scopeStack.peek(), returnType, sigArgTypes.toArray(new String[0])); } catch (Exception ex) { System.out.println( "Failed to get signature for method " + mt + " message: " + ex.getMessage()); } int dim = 0; Type returnTypeType = null; if (TypeUtil.isArrayType(returnType)) { dim = TypeUtil.getArrayTypeDimension(returnType); returnType = TypeUtil.getArrayElementType(returnType); if (isGenericType(returnType)) { returnType = "Object"; } } if (TypeUtil.isPrimitiveType(returnType)) { String descriptor = TypeUtil.getDescriptor(returnType); returnTypeType = Type.getType(TypeUtil.getArrayDescriptor(descriptor, dim)); } else { int arrowPos = returnType.indexOf("<"); if (arrowPos != -1) { returnType = returnType.substring(0, arrowPos); } ClassNode stub = scopeStack.peek().findStub(returnType); if (stub == null) { System.out.println("Type params is " + mt.getTypeParameters()); System.out.println("Type kind is " + mt.getReturnType().getKind()); throw new RuntimeException("Could not find class for " + returnType); } returnTypeType = Type.getObjectType(stub.name); returnTypeType = Type .getType(TypeUtil.getArrayDescriptor(returnTypeType.getInternalName(), dim)); } String methodDescriptor = null; if (argTypes.isEmpty()) { methodDescriptor = Type.getMethodDescriptor(returnTypeType); } else { methodDescriptor = Type.getMethodDescriptor(returnTypeType, argTypes.toArray(new Type[0])); } int flags = getFlags(mt.getModifiers().getFlags()); if (isVarArgs) { flags |= Opcodes.ACC_VARARGS; //System.out.println("VarArgs "+flags); } classWriter.visitMethod(flags, mt.getName().toString(), methodDescriptor, methodSignature, null); } //methodStack.push(mt); //Object out= super.visitMethod(mt, p); //methodStack.pop(); return null; } //private boolean LinkedList<MethodTree> methodStack =new LinkedList<>(); @Override public Object visitVariable(VariableTree vt, Object p) { ClassWriter classWriter = cwStack.peek(); String varType = vt.getType().toString(); if (isGenericType(varType)) { varType = "Object"; } String signature = null; try { signature = TypeUtil.getTypeSignature(varType, scopeStack.peek()); } catch (Exception ex) { System.out.println("Failed to generate signature for type " + varType); } int dim = 0; Type varTypeType = null; if (TypeUtil.isArrayType(varType)) { dim = TypeUtil.getArrayTypeDimension(varType); varType = TypeUtil.getArrayElementType(varType); } if (TypeUtil.isPrimitiveType(varType)) { String descriptor = TypeUtil.getDescriptor(varType); varTypeType = Type.getType(TypeUtil.getArrayDescriptor(descriptor, dim)); } else { int arrowPos = varType.indexOf("<"); if (arrowPos != -1) { varType = varType.substring(0, arrowPos); } ClassNode stub = scopeStack.peek().findStub(varType); if (stub == null) { throw new RuntimeException("Could not find class for " + varType); } varTypeType = Type.getObjectType(stub.name); varTypeType = Type.getType(TypeUtil.getArrayDescriptor(varTypeType.getInternalName(), dim)); } classWriter.visitField(getFlags(vt.getModifiers().getFlags()), vt.getName().toString(), varTypeType.toString(), signature, null); return super.visitVariable(vt, p); //To change body of generated methods, choose Tools | Templates. } boolean isGenericType(String type) { for (List<? extends TypeParameterTree> types : typeParametersStack) { for (TypeParameterTree tree : types) { if (type.equals(tree.getName().toString())) { return true; } } } return false; } /** * Converts modifier flags from Javac Tree into int flags usable in * TypeMirror * @param mods * @return */ int getFlags(Set<Modifier> mods) { int flags = 0; for (Modifier m : mods) { switch (m) { case ABSTRACT: flags |= Opcodes.ACC_ABSTRACT; break; case FINAL: flags |= Opcodes.ACC_FINAL; break; case PRIVATE: flags |= Opcodes.ACC_PRIVATE; break; case PROTECTED: flags |= Opcodes.ACC_PROTECTED; break; case PUBLIC: flags |= Opcodes.ACC_PUBLIC; break; case STATIC: flags |= Opcodes.ACC_STATIC; break; } } return flags; } @Override public Object visitClass(ClassTree ct, Object p) { //System.out.println("Visiting class "+ct); //System.out.println("Type parameters: "+ct.getTypeParameters()); typeParametersStack.push(ct.getTypeParameters()); String simpleName = ct.getSimpleName().toString(); String internalName = getThisInternalName(simpleName); int lastDollar = internalName.lastIndexOf("$"); String externalName = lastDollar == -1 ? null : internalName.substring(0, lastDollar); String supername = "java.lang.Object"; String[] interfaces = null; boolean targetClass = false; if (!cwStack.isEmpty()) { cwStack.peek().visitInnerClass(internalName, externalName, simpleName, getFlags(ct.getModifiers().getFlags())); } targetClass = true; // This is the one that we' //String supername = "java.lang.Object"; if (ct.getExtendsClause() != null) { supername = ct.getExtendsClause().toString().trim(); } String unresolvedSuperName = supername; int bracketPos = supername.indexOf("<"); supername = bracketPos == -1 ? supername : supername.substring(0, bracketPos); ClassNode node = scopeStack.peek().findStub(supername); if (node == null) { throw new RuntimeException("Could not find super stub " + supername); } supername = node.name; String impl = ct.getImplementsClause().toString(); String[] unresolvedInterfaces = null; if (impl != null && !"".equals(impl)) { interfaces = impl.split(","); unresolvedInterfaces = new String[interfaces.length]; for (int i = 0; i < interfaces.length; i++) { String iface = interfaces[i]; unresolvedInterfaces[i] = interfaces[i]; iface = iface.trim(); ClassNode inode = scopeStack.peek().findStub(iface); assert inode != null; if (inode == null) { throw new RuntimeException("Could not find stub for interface " + iface); } System.out.println("interface " + iface); interfaces[i] = inode.name; } } String signature = TypeUtil.getClassSignature(scopeStack.peek(), null, unresolvedSuperName, unresolvedInterfaces); int flags = getFlags(ct.getModifiers().getFlags()); switch (ct.getKind()) { case INTERFACE: flags |= Opcodes.ACC_INTERFACE; break; case ENUM: flags |= Opcodes.ACC_ENUM; break; } ClassWriter classWriter = new ClassWriter(49); classWriter.visit(49, flags, internalName, signature, supername, interfaces ); cwStack.push(classWriter); classInfoStack.push(new ClassInfo()); stack.push(simpleName); ClassFinder scope = new ClassFinder(context.get(ClassLoader.class), scopeStack.peek()); scope.addImport(internalName.replaceAll("/", ".").replaceAll("\\$", ".") + ".*" ); scope.addImport(internalName.replaceAll("/", ".").replaceAll("\\$", ".")); scope.addImport(supername.replaceAll("/", ".").replaceAll("\\$", ".") + ".*" ); scope.addImport(supername.replaceAll("/", ".").replaceAll("\\$", ".")); if (interfaces != null) { for (int i = 0; i < interfaces.length; i++) { scope.addImport(interfaces[i].replaceAll("/", ".").replaceAll("\\$", ".") + ".*" ); scope.addImport(interfaces[i].replaceAll("/", ".").replaceAll("\\$", ".")); } } for (TypeParameterTree tpTree : ct.getTypeParameters()) { //System.out.println("Name: "+tpTree.getName()); //System.out.println("Kind: "+tpTree.getKind().name()); //System.out.println("Bounds: "+tpTree.getBounds()); String bounds = (tpTree.getBounds() != null && !tpTree.getBounds().isEmpty()) ? tpTree.getBounds().get(0).toString() : "java.lang.Object"; scope.addTypeParameter(tpTree.getName().toString(), bounds); } scopeStack.push(scope); Object out = super.visitClass(ct, p); stack.pop(); scopeStack.pop(); ClassInfo classInfo = classInfoStack.pop(); if (classInfo.numConstructors == 0) { // there are no declared constructors in this class // we need to add a default constructor. cwStack.peek().visitMethod(Opcodes.ACC_PUBLIC, "<init>", Type.getMethodDescriptor(Type.getType("V")), null, null); classInfo.numConstructors++; } if (targetClass) { byte[] bytes = cwStack.peek().toByteArray(); outMap.put(internalName, bytes); cwStack.pop(); } typeParametersStack.pop(); return out; } }; scanner.scan(asts, null); return outMap; } public byte[] compile(final Type type, File sourceFile) throws IOException { Map<String, byte[]> out = compile(Collections.singletonList(type), sourceFile); return out.get(type.getInternalName()); } public void compile() throws IOException { } }