private static byte[] visitEnd() { ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS); cw.visit(Opcodes.V1_1, Opcodes.ACC_PUBLIC, RubyIDClassName, null, "java/lang/Object", null); Method staticBlock = Method.getMethod("void <clinit> ()V"); GeneratorAdapter staticBlockMg = new GeneratorAdapter(Opcodes.ACC_STATIC, staticBlock, null, null, cw); for (Map.Entry<String, String> e : idMap.entrySet()) { cw.visitField( Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, e.getValue(), Types.RUBY_ID_TYPE.getDescriptor(), null, null); staticBlockMg.push(e.getKey()); staticBlockMg.invokeStatic( Type.getType(RubyID.class), Method.getMethod("com.xruby.runtime.lang.RubyID intern(String)")); staticBlockMg.putStatic( Type.getType("L" + RubyIDClassName + ";"), e.getValue(), Types.RUBY_ID_TYPE); } staticBlockMg.returnValue(); staticBlockMg.endMethod(); cw.visitEnd(); return cw.toByteArray(); }
private static void createProperty(ClassWriter cw, String classType, ASMProperty property) throws PageException { String name = property.getName(); Type type = property.getASMType(); Class clazz = property.getClazz(); cw.visitField(Opcodes.ACC_PRIVATE, name, type.toString(), null, null).visitEnd(); int load = loadFor(type); // int sizeOf=sizeOf(type); // get<PropertyName>():<type> Type[] types = new Type[0]; Method method = new Method( (clazz == boolean.class ? "get" : "get") + StringUtil.ucFirst(name), type, types); GeneratorAdapter adapter = new GeneratorAdapter(Opcodes.ACC_PUBLIC, method, null, null, cw); Label start = new Label(); adapter.visitLabel(start); adapter.visitVarInsn(Opcodes.ALOAD, 0); adapter.visitFieldInsn(Opcodes.GETFIELD, classType, name, type.toString()); adapter.returnValue(); Label end = new Label(); adapter.visitLabel(end); adapter.visitLocalVariable("this", "L" + classType + ";", null, start, end, 0); adapter.visitEnd(); adapter.endMethod(); // set<PropertyName>(object):void types = new Type[] {type}; method = new Method("set" + StringUtil.ucFirst(name), Types.VOID, types); adapter = new GeneratorAdapter(Opcodes.ACC_PUBLIC, method, null, null, cw); start = new Label(); adapter.visitLabel(start); adapter.visitVarInsn(Opcodes.ALOAD, 0); adapter.visitVarInsn(load, 1); adapter.visitFieldInsn(Opcodes.PUTFIELD, classType, name, type.toString()); adapter.visitInsn(Opcodes.RETURN); end = new Label(); adapter.visitLabel(end); adapter.visitLocalVariable("this", "L" + classType + ";", null, start, end, 0); adapter.visitLocalVariable(name, type.toString(), null, start, end, 1); // adapter.visitMaxs(0, 0);//.visitMaxs(sizeOf+1, sizeOf+1);// hansx adapter.visitEnd(); adapter.endMethod(); }
public static void main(final String args[]) throws Exception { // Generates the bytecode corresponding to the following Java class: // // public class Example { // public static void main (String[] args) { // System.out.println("Hello world!"); // } // } // creates a ClassWriter for the Example public class, // which inherits from Object ClassWriter cw = new ClassWriter(0); cw.visit(V1_1, ACC_PUBLIC, "Example", null, "java/lang/Object", null); // creates a MethodWriter for the (implicit) constructor MethodVisitor mw = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null); // pushes the 'this' variable mw.visitVarInsn(ALOAD, 0); // invokes the super class constructor mw.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V"); mw.visitInsn(RETURN); // this code uses a maximum of one stack element and one local variable mw.visitMaxs(1, 1); mw.visitEnd(); // creates a MethodWriter for the 'main' method mw = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null); // pushes the 'out' field (of type PrintStream) of the System class mw.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;"); // pushes the "Hello World!" String constant mw.visitLdcInsn("Hello world!"); // invokes the 'println' method (defined in the PrintStream class) mw.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V"); mw.visitInsn(RETURN); // this code uses a maximum of two stack elements and two local // variables mw.visitMaxs(2, 2); mw.visitEnd(); // gets the bytecode of the Example class, and loads it dynamically byte[] code = cw.toByteArray(); FileOutputStream fos = new FileOutputStream("Example.class"); fos.write(code); fos.close(); Helloworld loader = new Helloworld(); Class<?> exampleClass = loader.defineClass("Example", code, 0, code.length); // uses the dynamically generated class to print 'Helloworld' exampleClass.getMethods()[0].invoke(null, new Object[] {null}); // ------------------------------------------------------------------------ // Same example with a GeneratorAdapter (more convenient but slower) // ------------------------------------------------------------------------ cw = new ClassWriter(ClassWriter.COMPUTE_MAXS); cw.visit(V1_1, ACC_PUBLIC, "Example", null, "java/lang/Object", null); // creates a GeneratorAdapter for the (implicit) constructor Method m = Method.getMethod("void <init> ()"); GeneratorAdapter mg = new GeneratorAdapter(ACC_PUBLIC, m, null, null, cw); mg.loadThis(); mg.invokeConstructor(Type.getType(Object.class), m); mg.returnValue(); mg.endMethod(); // creates a GeneratorAdapter for the 'main' method m = Method.getMethod("void main (String[])"); mg = new GeneratorAdapter(ACC_PUBLIC + ACC_STATIC, m, null, null, cw); mg.getStatic(Type.getType(System.class), "out", Type.getType(PrintStream.class)); mg.push("Hello world!"); mg.invokeVirtual(Type.getType(PrintStream.class), Method.getMethod("void println (String)")); mg.returnValue(); mg.endMethod(); cw.visitEnd(); code = cw.toByteArray(); loader = new Helloworld(); exampleClass = loader.defineClass("Example", code, 0, code.length); // uses the dynamically generated class to print 'Helloworld' exampleClass.getMethods()[0].invoke(null, new Object[] {null}); }
public static byte[] createPojo( String className, ASMProperty[] properties, Class parent, Class[] interfaces, String srcName) throws PageException { className = className.replace('.', '/'); className = className.replace('\\', '/'); className = ListUtil.trim(className, "/"); String[] inter = null; if (interfaces != null) { inter = new String[interfaces.length]; for (int i = 0; i < inter.length; i++) { inter[i] = interfaces[i].getName().replace('.', '/'); } } // CREATE CLASS ClassWriter cw = ASMUtil.getClassWriter(); cw.visit( Opcodes.V1_6, Opcodes.ACC_PUBLIC, className, null, parent.getName().replace('.', '/'), inter); String md5; try { md5 = createMD5(properties); } catch (Throwable t) { md5 = ""; t.printStackTrace(); } FieldVisitor fv = cw.visitField( Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_STATIC, "_md5_", "Ljava/lang/String;", null, md5); fv.visitEnd(); // Constructor GeneratorAdapter adapter = new GeneratorAdapter(Opcodes.ACC_PUBLIC, CONSTRUCTOR_OBJECT, null, null, cw); adapter.loadThis(); adapter.invokeConstructor(toType(parent, true), CONSTRUCTOR_OBJECT); adapter.returnValue(); adapter.endMethod(); // properties for (int i = 0; i < properties.length; i++) { createProperty(cw, className, properties[i]); } // complexType src if (!StringUtil.isEmpty(srcName)) { GeneratorAdapter _adapter = new GeneratorAdapter( Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_STATIC, _SRC_NAME, null, null, cw); _adapter.push(srcName); _adapter.returnValue(); _adapter.endMethod(); } cw.visitEnd(); return cw.toByteArray(); }