动态代理同一个类中方法相互调用特点

川长思鸟来 2022-12-11 04:29 139阅读 0赞

public interface XxxService {
        // a -> b
        void a();
        void b();
    }

@Slf4j
    public class XxxServiceImpl implements XxxService {
        @Override
        public void a() {
            log.info("a()");
            // 注意这样调用方法，b方法不是通过代理类去访问的
            // 在Spring中，同一个类中一个方法去调用（不管有没有注解）另外一个有注解（比如@Async，@Transational）的方法，被调用的那个方法的注解是不会生效的
            this.b();
        }
        @Override
        public void b() {
            log.info("b()");
        }
    }

@Slf4j
    public class DynamicLogProxy implements InvocationHandler {
        private final Object target;
        public DynamicLogProxy(Object target) {
            this.target = target;
        }
        public Object getProxyInstance() {
            Class<?> clazz = target.getClass();
            return Proxy.newProxyInstance(clazz.getClassLoader(), clazz.getInterfaces(), this);
        }
        @Override
        public Object invoke(Object obj, Method method, Object[] args) throws Throwable {
            if (Object.class.equals(method.getDeclaringClass())) {
                return method.invoke(this, args);
            }
            log.info("执行方法前做些什么...");
            Object invoke = method.invoke(target, args);
            log.info("执行方法后做些什么...");
            return invoke;
        }
    }

@Test
    public void test_proxy(){
        XxxServiceImpl xxxService = new XxxServiceImpl();
        XxxService proxy = (XxxService) new DynamicLogProxy(xxxService).getProxyInstance();
        proxy.a();
        //proxy.b();
    }

<?xml version="1.0" encoding="UTF-8"?>
    <Configuration status="warn" monitorInterval="5">
        <Appenders>
            <Console name="console" target="SYSTEM_OUT">
                <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
            </Console>
        </Appenders>
        <Loggers>
            <Root level="trace">
                <AppenderRef ref="console"/>
            </Root>
        </Loggers>
    </Configuration>

> [https://blog.csdn.net/u011186019/article/details/80210593][https_blog.csdn.net_u011186019_article_details_80210593]

[https_blog.csdn.net_u011186019_article_details_80210593]: https://blog.csdn.net/u011186019/article/details/80210593