CGLib可以为那些方法生成代理

布满荆棘的人生 2022-12-12 02:14 107阅读 0赞

> [https://yuanyu.blog.csdn.net/article/details/108754891][https_yuanyu.blog.csdn.net_article_details_108754891]

CGLib通过ASM动态操作指令生成了被代理类的子类，重写了目标类中所有的非private、非final、非static方法

**public&protected&默认**

public class RealSubject {
        public void m1() {
            System.out.println("public...");
        }
        private void m2() {
            System.out.println("private...");
        }
        protected void m3() {
            System.out.println("protected...");
        }
        void m4() {
            System.out.println("package...");
        }
        public final void m5() {
            System.out.println("final...");
        }
        // static
        public static void m10() {
            System.out.println("public static...");
        }
        private static void m11() {
            System.out.println("private static...");
        }
    
        // 测试 private
        public static void main(String[] args) {
            RealSubject realSubject = new RealSubject();
            RealSubject proxy = (RealSubject) new DynamicCglibProxy(realSubject).getProxyInstance();
            proxy.m2();  // private 不可以
            proxy.m11(); // private static 不可以
        }
    }

public class DynamicCglibProxy implements MethodInterceptor {
        private final Object target;
        public DynamicCglibProxy(Object target) {
            this.target = target;
        }
        /**
         * 返回一个代理对象
         */
        public Object getProxyInstance() {
            Enhancer enhancer = new Enhancer();
            enhancer.setSuperclass(target.getClass());
            enhancer.setCallback(this);
            enhancer.setUseCache(false);
            return enhancer.create();
        }
        @Override
        public Object intercept(Object obj, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
            // 不做处理
            if (Object.class.equals(method.getDeclaringClass())) {
                return method.invoke(target, args);
            }
            System.out.println("proxy start...");
            Object res = method.invoke(target, args);
            System.out.println("proxy end...");
            System.out.println();
            return res;
        }
    }

public class DynamicTest {
        public static void main(String[] args) {
            RealSubject realSubject = new RealSubject();
            RealSubject proxy = (RealSubject) new DynamicCglibProxy(realSubject).getProxyInstance();
            proxy.m1();     // public 可以
            proxy.m3();     // protected 可以
            proxy.m4();     // 默认 可以
            proxy.m5();     // final 不可以
    
            proxy.m10();    // public static 不可以
        }
    }

>  *  [https://www.jb51.net/article/120309.htm][https_www.jb51.net_article_120309.htm]
>  *  [https://www.oschina.net/question/1457994\_2302959][https_www.oschina.net_question_1457994_2302959]
>  *  [https://www.jianshu.com/p/6b740b0ed34e][https_www.jianshu.com_p_6b740b0ed34e]
>  *  [https://blog.csdn.net/P19777/article/details/103967383][https_blog.csdn.net_P19777_article_details_103967383]

[https_yuanyu.blog.csdn.net_article_details_108754891]: https://yuanyu.blog.csdn.net/article/details/108754891
[https_www.jb51.net_article_120309.htm]: https://www.jb51.net/article/120309.htm
[https_www.oschina.net_question_1457994_2302959]: https://www.oschina.net/question/1457994_2302959
[https_www.jianshu.com_p_6b740b0ed34e]: https://www.jianshu.com/p/6b740b0ed34e
[https_blog.csdn.net_P19777_article_details_103967383]: https://blog.csdn.net/P19777/article/details/103967383