org.apache.bcel.generic.InstructionFactory Java Examples

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, new Type[] { Type.OBJECT },
          new String[] { "arg0" }, "test", TEST_PACKAGE+".TestArrayAccess03", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(new ObjectType(TEST_PACKAGE+".TestArrayAccess03"), (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_5 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(_factory.createNew(TEST_PACKAGE+".TestArrayAccess03"));
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke(TEST_PACKAGE+".TestArrayAccess03", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_15 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_15); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, Type.NO_ARGS,
          new String[] {  }, "foo", TEST_PACKAGE+".TestReturn01", il, _cp);

  final InstructionHandle ih_0 = il.append(_factory.createNew("java.lang.Object"));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.NOP);
  final InstructionHandle ih_8 = il.append(InstructionFactory.createReturn(Type.OBJECT));
  Assert.assertNotNull(ih_8); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, new Type[] { Type.OBJECT },
          new String[] { "arg0" }, "test", TEST_PACKAGE+".TestArrayAccess04", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(Type.OBJECT, (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_5 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(InstructionFactory.createStore(Type.INT, 2));
  final InstructionHandle ih_7 = il.append(InstructionFactory.createLoad(Type.OBJECT, 1));
  Assert.assertNotNull(ih_7); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(InstructionFactory.createLoad(Type.INT, 2));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_11 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_11); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess04", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess03", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

public TestArrayAccess03Creator() {
  _cg = new ClassGen(TEST_PACKAGE+".TestArrayAccess03", "java.lang.Object", "TestArrayAccess03.java",
          Const.ACC_PUBLIC | Const.ACC_SUPER, new String[] {  });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "test", TEST_PACKAGE+".TestArrayAccess02", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(new ObjectType(TEST_PACKAGE+".TestArrayAccess02"), (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 0));
  final InstructionHandle ih_5 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(_factory.createNewArray(Type.STRING, (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_10 = il.append(InstructionFactory.createLoad(Type.OBJECT, 1));
  Assert.assertNotNull(ih_10); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(_factory.createNew(TEST_PACKAGE+".TestArrayAccess02"));
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke(TEST_PACKAGE+".TestArrayAccess02", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_20 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_20); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess02", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

public TestArrayAccess02Creator() {
  _cg = new ClassGen(TEST_PACKAGE+".TestArrayAccess02", "java.lang.Object", "TestArrayAccess02.java",
          Const.ACC_PUBLIC | Const.ACC_SUPER, new String[] {  });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.INT, Type.NO_ARGS,
          new String[] {  }, "test3", TEST_PACKAGE+".TestReturn03", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionConst.ACONST_NULL);
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(InstructionFactory.createReturn(Type.OBJECT));
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "<init>", TEST_PACKAGE+".TestReturn03", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

public TestReturn03Creator() {
  _cg = new ClassGen(TEST_PACKAGE+".TestReturn03", "java.lang.Object", "TestReturn03.java",
          Const.ACC_PUBLIC | Const.ACC_SUPER, new String[] {  });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
}
 

/**
 * Creates the LDAPSocketFactoryImpl class (subclass of {@link AbstractLDAPSSLSocketFactory}.
 * A static method #getDefaulta, a static field _sslContent and no-arg constructor are added
 * to the class.
 *
 * @param className
 *
 * @return byte code
 */
private static byte[] createSubClassByteCode(final String className)
{
    ClassGen classGen = new ClassGen(className,
            AbstractLDAPSSLSocketFactory.class.getName(),
            "<generated>",
            ACC_PUBLIC | ACC_SUPER,
            null);
    ConstantPoolGen constantPoolGen = classGen.getConstantPool();
    InstructionFactory factory = new InstructionFactory(classGen);

    createSslContextStaticField(classGen, constantPoolGen);
    createGetDefaultStaticMethod(classGen, constantPoolGen, factory);

    classGen.addEmptyConstructor(ACC_PROTECTED);

    JavaClass javaClass = classGen.getJavaClass();
    ByteArrayOutputStream out = null;
    try
    {
        out = new ByteArrayOutputStream();
        javaClass.dump(out);
        return out.toByteArray();
    }
    catch (IOException ioex)
    {
        throw new IllegalStateException("Could not write to a ByteArrayOutputStream - should not happen", ioex);
    }
    finally
    {
        closeSafely(out);
    }
}
 

public TestArrayAccess04Creator() {
  _cg = new ClassGen(TEST_PACKAGE+".TestArrayAccess04", "java.lang.Object", "TestArrayAccess04.java",
          Const.ACC_PUBLIC | Const.ACC_SUPER, new String[] {  });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "<init>", TEST_PACKAGE+".TestReturn01", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

public TestReturn01Creator() {
  _cg = new ClassGen(TEST_PACKAGE+".TestReturn01", "java.lang.Object", "TestReturn01.java",
          Const.ACC_PUBLIC | Const.ACC_SUPER, new String[] {  });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
}
 

public ComplexObjectCreator(String objectType) {
  _cg = new ClassGen(objectType, "java.lang.Object", "ComplexObject.java", ACC_PUBLIC | ACC_SUPER, new String[] { "com.betfair.cougar.api.Result" });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
  this.objectType = objectType;
}
 

public ComplexObjectCreator(String objectType) {
  _cg = new ClassGen(objectType, "java.lang.Object", "ComplexObject.java", ACC_PUBLIC | ACC_SUPER, new String[] { "com.betfair.cougar.api.Result" });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
  this.objectType = objectType;
}
 

public ComplexObjectCreator(String objectType) {
  _cg = new ClassGen(objectType, "java.lang.Object", "ComplexObject.java", ACC_PUBLIC | ACC_SUPER, new String[] { "com.betfair.cougar.api.Result" });

  _cp = _cg.getConstantPool();
  _factory = new InstructionFactory(_cg, _cp);
  this.objectType = objectType;
}
 

/**
 * Create a static method 'getDefault' returning {@link SocketFactory}
 * that creates a new instance of the sub-class and calls its no-argument
 * constructor, the newly created is returned to the caller.
 *
 * @param classGen
 * @param constantPoolGen
 * @param instructionFactory
 */
private static void createGetDefaultStaticMethod(ClassGen classGen,
        ConstantPoolGen constantPoolGen, InstructionFactory instructionFactory)
{
    InstructionList il = new InstructionList();

    String methodName = "getDefault";
    MethodGen mg = new MethodGen(ACC_STATIC | ACC_PUBLIC, // access flags
                        Type.getType(SSLSocketFactory.class),  // return type
                        new Type[0],   // argument types - no args
                        new String[0], // arg names - no args
                        methodName,
                        classGen.getClassName(),    // method, class
                        il,
                        constantPoolGen);

    il.append(instructionFactory.createNew(classGen.getClassName()));
    il.append(InstructionConst.DUP);

    il.append(instructionFactory.createInvoke(classGen.getClassName(), "<init>", Type.VOID,
                                   new Type[] {},
                                   INVOKESPECIAL));

    il.append(InstructionConst.ARETURN);

    mg.setMaxStack();
    classGen.addMethod(mg.getMethod());
    il.dispose();
}
 

/**
 * Create JavaClass object for a simple proxy for an java.awt.event.ActionListener
 * that just prints the passed arguments, load and use it via the class loader
 * mechanism.
 */
public static void main(final String[] argv) throws Exception {
    final ClassLoader loader = ProxyCreator.class.getClassLoader();

    // instanceof won't work here ...
    // TODO this is broken; cannot ever be true now that ClassLoader has been dropped
    if (loader.getClass().toString().equals("class org.apache.bcel.util.ClassLoader")) {
        // Real class name will be set by the class loader
        final ClassGen cg = new ClassGen("foo", "java.lang.Object", "", Constants.ACC_PUBLIC,
                new String[]{"java.awt.event.ActionListener"});

        // That's important, otherwise newInstance() won't work
        cg.addEmptyConstructor(Constants.ACC_PUBLIC);

        final InstructionList il = new InstructionList();
        final ConstantPoolGen cp = cg.getConstantPool();
        final InstructionFactory factory = new InstructionFactory(cg);

        final int out = cp.addFieldref("java.lang.System", "out",
                "Ljava/io/PrintStream;");
        final int println = cp.addMethodref("java.io.PrintStream", "println",
                "(Ljava/lang/Object;)V");
        final MethodGen mg = new MethodGen(Constants.ACC_PUBLIC, Type.VOID,
                new Type[]{
                        new ObjectType("java.awt.event.ActionEvent")
                }, null, "actionPerformed", "foo", il, cp);

        // System.out.println("actionPerformed:" + event);
        il.append(new GETSTATIC(out));
        il.append(factory.createNew("java.lang.StringBuffer"));
        il.append(InstructionConstants.DUP);
        il.append(new PUSH(cp, "actionPerformed:"));
        il.append(factory.createInvoke("java.lang.StringBuffer", "<init>", Type.VOID,
                new Type[]{Type.STRING}, Constants.INVOKESPECIAL));

        il.append(new ALOAD(1));
        il.append(factory.createAppend(Type.OBJECT));
        il.append(new INVOKEVIRTUAL(println));
        il.append(InstructionConstants.RETURN);

        mg.stripAttributes(true);
        mg.setMaxStack();
        mg.setMaxLocals();
        cg.addMethod(mg.getMethod());

        final byte[] bytes = cg.getJavaClass().getBytes();

        System.out.println("Uncompressed class: " + bytes.length);

        final String s = Utility.encode(bytes, true);
        System.out.println("Encoded class: " + s.length());

        System.out.print("Creating proxy ... ");
        final ActionListener a = (ActionListener) createProxy("foo.bar.", s);
        System.out.println("Done. Now calling actionPerformed()");

        a.actionPerformed(new ActionEvent(a, ActionEvent.ACTION_PERFORMED, "hello"));
    } else {
        System.err.println("Call me with java org.apache.bcel.util.JavaWrapper ProxyCreator");
    }
}
 

public JavaBuilder(ProtoInfo pi, String classname, String filename) {
	this.pi = pi;
	this.p = pi.prototype;
	this.classname = classname;
	
	// what class to inherit from
	superclassType = p.numparams;
	if ( p.is_vararg != 0 || superclassType >= SUPERTYPE_VARARGS )
		superclassType = SUPERTYPE_VARARGS;
	for ( int i=0, n=p.code.length; i<n; i++ ) {
		int inst = p.code[i];
		int o = Lua.GET_OPCODE(inst);
		if ( (o == Lua.OP_TAILCALL) ||
		     ((o == Lua.OP_RETURN) && (Lua.GETARG_B(inst) < 1 || Lua.GETARG_B(inst) > 2)) ) {
			superclassType = SUPERTYPE_VARARGS;
			break;
		}
	}
	
	// create class generator
	cg = new ClassGen(classname, SUPER_NAME_N[superclassType], filename,
			Constants.ACC_PUBLIC | Constants.ACC_SUPER, null);
	cp = cg.getConstantPool(); // cg creates constant pool

	// main instruction lists
	factory = new InstructionFactory(cg);
	init = new InstructionList();
	main = new InstructionList();

	// create the fields
	for ( int i=0; i<p.upvalues.length; i++ ) {
		boolean isrw = pi.isReadWriteUpvalue( pi.upvals[i] ); 
		Type uptype = isrw? (Type) TYPE_LOCALUPVALUE: (Type) TYPE_LUAVALUE;
		FieldGen fg = new FieldGen(0, uptype, upvalueName(i), cp);
		cg.addField(fg.getField());
	}
	
	// create the method
	mg = new MethodGen( Constants.ACC_PUBLIC | Constants.ACC_FINAL, // access flags
			RETURN_TYPE_N[superclassType], // return type
			ARG_TYPES_N[superclassType], // argument types
			ARG_NAMES_N[superclassType], // arg names
			METH_NAME_N[superclassType], 
			STR_LUAVALUE, // method, defining class
			main, cp);
	
	// initialize the values in the slots
	initializeSlots();	

	// initialize branching
	int nc = p.code.length;
	targets = new int[nc];
	branches = new BranchInstruction[nc];
	branchDestHandles = new InstructionHandle[nc];
	lastInstrHandles = new InstructionHandle[nc];
}