private static void defineMethod()

in deltaspike/modules/proxy/impl-asm/src/main/java/org/apache/deltaspike/proxy/impl/AsmDeltaSpikeProxyClassGenerator.java [334:432]
72 lines of code
8 McCabe index (conditional complexity)

    private static void defineMethod(ClassWriter cw, java.lang.reflect.Method method, Type proxyType)
    {
        Type methodType = Type.getType(method);
        
        ArrayList<Type> exceptionsToCatch = new ArrayList<Type>();
        for (Class<?> exception : method.getExceptionTypes())
        {
            if (!RuntimeException.class.isAssignableFrom(exception))
            {
                exceptionsToCatch.add(Type.getType(exception));
            }
        }
        
        // push the method definition
        int modifiers = (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED) & method.getModifiers();
        Method asmMethod = Method.getMethod(method);
        GeneratorAdapter mg = new GeneratorAdapter(modifiers,
                asmMethod,
                null,
                getTypes(method.getExceptionTypes()),
                cw);

        // copy annotations
        for (Annotation annotation : method.getDeclaredAnnotations())
        {
            mg.visitAnnotation(Type.getDescriptor(annotation.annotationType()), true).visitEnd();
        }

        mg.visitCode();

        Label tryBlockStart = mg.mark();

        mg.loadThis();
        mg.getField(proxyType, FIELDNAME_INVOCATION_HANDLER, TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER);
        mg.loadThis();
        loadCurrentMethod(mg, method, methodType);
        loadArguments(mg, method, methodType);
        
        mg.invokeVirtual(TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER,
                Method.getMethod("Object invoke(Object, java.lang.reflect.Method, Object[])"));

        // cast the result
        mg.unbox(methodType.getReturnType());

        // build try catch
        Label tryBlockEnd = mg.mark();
        
        // push return
        mg.returnValue();

        // catch runtime exceptions and rethrow it
        Label rethrow = mg.mark();
        mg.visitVarInsn(Opcodes.ASTORE, 1);
        mg.visitVarInsn(Opcodes.ALOAD, 1);
        mg.throwException();
        mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, Type.getInternalName(RuntimeException.class));

        // catch checked exceptions and rethrow it
        boolean throwableCatched = false;
        if (!exceptionsToCatch.isEmpty())
        {
            rethrow = mg.mark();
            mg.visitVarInsn(Opcodes.ASTORE, 1);
            mg.visitVarInsn(Opcodes.ALOAD, 1);
            mg.throwException();

            // catch declared exceptions and rethrow it...
            for (Type exceptionType : exceptionsToCatch)
            {
                if (exceptionType.getClassName().equals(Throwable.class.getName()))
                {
                    throwableCatched = true;
                }
                mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, exceptionType.getInternalName());
            }
        }

        // if throwable isn't alreached cachted, catch it and wrap it with an UndeclaredThrowableException and throw it
        if (!throwableCatched)
        {
            Type uteType = Type.getType(UndeclaredThrowableException.class);
            Label wrapAndRethrow = mg.mark();

            mg.visitVarInsn(Opcodes.ASTORE, 1);
            mg.newInstance(uteType);
            mg.dup();
            mg.visitVarInsn(Opcodes.ALOAD, 1);
            mg.invokeConstructor(uteType,
                    Method.getMethod("void <init>(java.lang.Throwable)"));
            mg.throwException();

            mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, wrapAndRethrow, Type.getInternalName(Throwable.class));
        }

        // finish the method
        mg.endMethod();
        mg.visitMaxs(12, 12);
        mg.visitEnd();
    }