Aop.rar_aop_java aop

/** * Create on 2011-10-13 下午04:29:04 by tengfei.fangtf * * Copyright 1999-2100 Alibaba.com Corporation Limited. * * All rights reserved. */ package jsvassist; import javassist.CannotCompileException; import javassist.ClassPool; import javassist.CtClass; import javassist.CtMethod; import javassist.NotFoundException; import javassist.Translator; import model.Business; /** * 使用Javassist演示Aop的Demo. * * @author tengfei.fangtf */ public class JavassistAopDemo { public static void main(String[] args) throws Exception { aop(); } public static void aop() throws NotFoundException, CannotCompileException, InstantiationException, IllegalAccessException { //获取存放CtClass的容器ClassPool ClassPool cp = ClassPool.getDefault(); // //创建一个类加载器 // Loader cl = new Loader(); // //增加一个转换器，让类加载的时候 // cl.addTranslator(cp, new MyTranslator()); // //将类装载到JVM // try { // cl.run("jsvassist.JavassistAopDemo$MyTranslator", null); // } catch (Throwable e) { // // TODO Auto-generated catch block // e.printStackTrace(); // } CtClass cc = cp.get("model.Business"); //获得指定方法名的方法 CtMethod m = cc.getDeclaredMethod("doSomeThing"); //在方法执行前插入代码 m.insertBefore("{ System.out.println(\"记录日志\"); }"); ((Business)cc.toClass().newInstance()).doSomeThing(); } public static class MyTranslator implements Translator { public void start(ClassPool pool) throws NotFoundException, CannotCompileException { } /* * * 类装载到JVM前进行代码织入 */ public void onLoad(ClassPool pool, String classname) { if (!"model.Business".equals(classname)) { return; } //通过报名获取类文件 try { CtClass cc = pool.get(classname); //获得指定方法名的方法 CtMethod m = cc.getDeclaredMethod("doSomeThing"); //在方法执行前插入代码 m.insertBefore("{ System.out.println(\"记录日志\"); }"); } catch (NotFoundException e) { } catch (CannotCompileException e) { } } public static void main(String[] args) { Business b = new Business(); b.doSomeThing2(); b.doSomeThing(); } } }