1 package org.windwant.spring.core.proxy; 2  3 import javassist.ClassPool; 4 import javassist.CtClass; 5 import javassist.CtMethod; 6  7 /** 8  * Created by windwant on 2016/9/18. 9  */10 public class MyJavassistProxy {11 12     public Object getProxySelf(String clazz, String pClazz, String methodName, String methodBefore, String methodAfter){13         ClassPool cp = ClassPool.getDefault();14         CtClass ct;15         try {16             ct = cp.get(clazz);17             if(pClazz != null){18                 ct.setSuperclass(cp.get(pClazz));19             }20             ct.writeFile();21             ct.defrost();22             CtMethod m = ct.getDeclaredMethod(methodName);23             if(methodBefore != null) {24                 m.insertBefore(methodBefore);25             }26             if(methodAfter != null) {27                 m.insertAfter(methodAfter);28             }29             Class c = ct.toClass();30             return c.newInstance();31         } catch (Exception e) {32             e.printStackTrace();33         }34         return null;35     }36 37 }

1 public void testJavassist(){ 2         String clazz = "org.windwant.spring.core.proxy.Hello"; 3         String methodBefore = "{ System.out.println(\"method before...:\"); }"; 4         String methodAfter = "{ System.out.println(\"method after...:\"); }"; 5         String pClazz = "org.windwant.spring.core.proxy.HelloP"; 6  7         Hello hello = (Hello) new MyJavassistProxy().getProxySelf(clazz, null, "say", 8                 methodBefore, methodAfter); 9         hello.say();10     }