[编织消息框架][JAVA核心技术]动态代理应用8-IRpcReceive实现

    private static Map<Short, Map<Byte, Method>> RECEIVE_METHOD_INFO = new HashMap<>();

    public static <T> T registerReceiveProxy(Object obj) {
        Class<?> target = obj.getClass();
        if (target.isInterface()) {
            throw new RuntimeException("class is Interface : " + target);
        }
        QModel modelAnno = ReflectUtil.getAnno(target, QModel.class);
        String proxyClassName = target.getCanonicalName() + "$$receive$$";
        ClassPool classPool = JavassistHepler.classPool;
        CtClass ctClass = classPool.makeClass(proxyClassName);

        try {
            // 设置接口,继承 target
            CtClass[] interfaces = new CtClass[1];
            interfaces[0] = classPool.get(IRpcReceive.class.getName());
            ctClass.setInterfaces(interfaces);
            ctClass.setSuperclass(JavassistHepler.getCtClass(target));
            {
                // 添加this字段
                final String ctxName = target.getName();
                CtField ctField = new CtField(classPool.get(ctxName), "_this", ctClass);
                ctField.setModifiers(Modifier.PRIVATE | Modifier.FINAL);
                // 添加json 忽略anno
                ctField.getFieldInfo2().addAttribute(JavassistHepler.addAnno(JsonIgnore.class, ctClass));
                ctClass.addField(ctField);
            }

            Map<Byte, Method> methods = new HashMap<>();
            RECEIVE_METHOD_INFO.put(modelAnno.value(), methods);

            // 生成代理方法
            ReflectUtil.foreachMethods(target, (method) -> {
                QCommond commond = method.getAnnotation(QCommond.class);
                if (commond == null) {
                    return;
                }
                methods.put(commond.value(), method);
                String resultType = "";
                if (void.class != method.getReturnType()) {
                    resultType = " return ($r) ";
                }
                final String body = "{ " + resultType + "_this." + method.getName() + "($$); }";
                JavassistHepler.addMethod(ctClass, method, body);
            });

            // 生成receive method
            {
                final String body = "{return ($r) " + QRpcFactory.class.getName() + ".proxyReceive(_this,$2, (short)" + modelAnno.value() + "  ,(byte) $1);}";
                JavassistHepler.addMethod(ctClass, RECEIVE_METHOD, body);
            }

            // 添加构造方法 new XXProxy(XX)
            CtConstructor ctConstructor = new CtConstructor(JavassistHepler.toCtClassArray(target), ctClass);
            ctConstructor.setBody("{ this._this = $1; }");
            ctConstructor.setModifiers(Modifier.PUBLIC);
            ctClass.addConstructor(ctConstructor);
            Class<?> newClass = ctClass.toClass();
            Constructor<T> constructor = (Constructor<T>) newClass.getConstructor(target);
            constructor.setAccessible(true);
            ctClass.detach();
            Object ret = constructor.newInstance(obj);
            RECEIVE.put(modelAnno.value(), (IRpcReceive) ret);
            return (T) ret;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    // 因为 javassist $$ 表达式访问的 参数类型 为 object 获取不到目标类型，所以只能用 invoke 处理
    public static Object proxyReceive(Object target, Object[] args, short model, byte commondIndex) {
        Map<Byte, Method> methods = RECEIVE_METHOD_INFO.get(model);
        try {
            return methods.get(commondIndex).invoke(target, args);
        } catch (Exception e) {
            throw new QRpcException(QCode.ENHANCE_ERROR_RPC_NOFIND_MODEL, "proxyReceive ", e);
        }
    }
}

    @Test
    public void testReceive() {    
        TestObject proxy = QRpcFactory.registerReceiveProxy(new TestObjectImpl());

        proxy.a(1, "b");
        proxy.setAge(30);
        QResult<Integer> ret = proxy.getAge();
        System.out.println(ret.getResult());

        Object[] args = new Object[1];
        args[0] =18;
            
        ((IRpcReceive) proxy).receive((byte) 2, args);

        ret = proxy.getAge();
        System.out.println(ret.getResult());
        args[0] = new TestObject1();
        ((IRpcReceive) proxy).receive((byte) 4, args);
    }
    
    @Test
    public void testObjectArgs() {
        QRpcFactory.registerReceiveProxy(new TestObjectImpl());
        IRpcReceive obj = QRpcFactory.loadReceiveProxy((short)1);
        int a=30;
        Integer b= 30;
        double c=1d;
        List<Integer> d = new ArrayList<>();
        Integer[] e = new Integer[0];
        Object[] args = new Object[5];
        args[0] =a;
        args[1] =b;
        args[2] =c;
        args[3] =d;
        args[4] =e;

        obj.receive((byte)5, args);
    }

在实际开发时 因为 javassist $$ 表达式访问的参数类型为object 获取不到目标类型，编译时出现错误

Type 'java/lang/Object' (current frame, stack[1]) is not assignable to integer

所以只能用 invoke 处理