java 代理机制的实例详解
前言：
java代理分静态代理和动态代理，动态代理有jdk代理和cglib代理两种，在运行时生成新的子类class文件。本文主要练习下动态代理，代码用于备忘。对于代理的原理和机制，网上有很多写的很好的，就不班门弄斧了。
jdk代理
实例代码
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; public class ProxyFactory implements InvocationHandler { private Object tarjectObject; public Object creatProxyInstance(Object obj) { this.tarjectObject = obj; return Proxy.newProxyInstance(this.tarjectObject.getClass() .getClassLoader(), this.tarjectObject.getClass() .getInterfaces(), this); } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { Object result = null; if (AssessUtils.isAssess()) { result = method.invoke(this.tarjectObject, args); }else{ throw new NoAssessException("This server cannot run this service."); } return result; } } |
cglib代理
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
import java.lang.reflect.Method; import org.springframework.cglib.proxy.Enhancer; import org.springframework.cglib.proxy.MethodInterceptor; import org.springframework.cglib.proxy.MethodProxy; public class ProxyCglibFactory implements MethodInterceptor { private Object tarjectObject; public Object creatProxyInstance(Object obj) { this.tarjectObject = obj; Enhancer enhancer=new Enhancer(); enhancer.setSuperclass(this.tarjectObject.getClass()); enhancer.setCallback(this); return enhancer.create(); } @Override public Object intercept(Object obj, Method method, Object[] args, MethodProxy arg3) throws Throwable { Object result = null; if (AssessUtils.isAssess()) { result = method.invoke(this.tarjectObject, args); }else{ throw new NoAssessException("This server cannot run this service."); } return result; } } |
Aspect注解
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
import org.aspectj.lang.JoinPoint; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; @Aspectpublic class AssessInterceptor { @Pointcut(value="execution (* com..*.*(..))") private void anyMethod(){}; @Before("anyMethod()") public void doBefore(JoinPoint joinPoint) throws NoAssessException{ if (!AssessUtils.isAssess()) { throw new NoAssessException("This server cannot run this service."); } } /** * Around异常的时候调用 * @param pjp * @throws Throwable */ @Around("anyMethod()") public void invoke(ProceedingJoinPoint pjp) throws Throwable{ pjp.proceed(); } } |
以上就是java代理机制的实例，如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
原文链接：http://sheungxin.iteye.com/blog/2346329
