1.背景

在学习aop底层时遇到的问题,做个小结

2.现象

动态代理代码如下:

package com.ldp.proxy;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.Method;

/**
 * @Copyright (C) XXXXXXXXXXX科技股份技有限公司
 * @Author: lidongping
 * @Date: 2021-01-12 11:50
 * @Description:
 */
public class MyDaoCglibProxy implements MethodInterceptor {
    private Object target;

    public Object getInstance(Object target) {
        this.target = target;
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(this.target.getClass());
        // 设置回调方法
        enhancer.setCallback(this);
        // 创建代理对象
        return enhancer.create();
    }

    /**
     * 实现MethodInterceptor接口中重写的方法
     * <p>
     * 回调方法
     */
    @Override
    public Object intercept(Object object, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println("事务开始。。。");
        Object result = proxy.invokeSuper(object, args);
        System.out.println("事务结束。。。");
        return result;
    }
}

View Code

在使用cglib做一个小案例时报错如下:

java.lang.ExceptionInInitializerError
at com.ldp.proxy.MyDaoCglibProxy.getInstance(MyDaoCglibProxy.java:20)
at com.ldp.test.TestProxy.test03(TestProxy.java:80)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.IllegalStateException: Unable to load cache item
at net.sf.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:79)
at net.sf.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
at net.sf.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:119)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:294)
at net.sf.cglib.core.KeyFactory$Generator.create(KeyFactory.java:221)
at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:174)
at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:153)
at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:73)
... 24 more
Caused by: java.lang.IncompatibleClassChangeError: class net.sf.cglib.core.DebuggingClassWriter has interface org.objectweb.asm.ClassVisitor as super class
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at net.sf.cglib.core.DefaultGeneratorStrategy.getClassVisitor(DefaultGeneratorStrategy.java:30)
at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:24)
at net.sf.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:332)
at net.sf.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:96)
at net.sf.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:94)
at net.sf.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at net.sf.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
... 31 more

3.问题所在

依赖包sm-9.0.jar与cglib-3.3.0.jar包冲突

4.解决方案

使用asm-9.0.jar与cglib-3.3.0.jar能正常调用

完美!

解决CGLib动态代理测试不通过-Unable to load cache item

原文：https://www.cnblogs.com/newAndHui/p/14273862.html