CGlib与JDK动态代理

时间：2021-04-03 15:20:46

1 实现两种动态代理

1.1 JDK代理

JDK动态代理只能对接口实现代理
定义一个接口

public interface Service {
public abstract void say();
}

实现接口

public class ServiceImpl implements Service {
@Override
public void say() {
        System.out.println("Hello JDK");
    }
}

实现InvocationHandler

public class JDKInvocationHandler implements InvocationHandler {

// 目标对象
private Object target;
/**
 * 构造方法
 * @param target 目标对象
 */
public JDKInvocationHandler(Object target) {
super();
this.target = target;
    }
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// 在目标对象的方法执行之前简单的打印一下
        System.out.println("------------------before------------------");
// 执行目标对象的方法
        Object result = method.invoke(target, args);
// 在目标对象的方法执行之后简单的打印一下
        System.out.println("-------------------after------------------");

return result;
    }
public Object getProxy() {
return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
                target.getClass().getInterfaces(), this);
    }
}

测试类

public class TestJDKProxy {
public static void main(String[] a) {
// 实例化目标对象
        Service userService = new ServiceImpl();

// 实例化InvocationHandler
        JDKInvocationHandler invocationHandler = new JDKInvocationHandler(userService);

// 根据目标对象生成代理对象
        Service proxy = (Service) invocationHandler.getProxy();

// 调用代理对象的方法
        proxy.say();
//将生成的代理类写到E盘
        writeProxyClassToHardDisk("E:/$Proxy11.class");
    }
public static void writeProxyClassToHardDisk(String path) {
byte[] classFile = ProxyGenerator.generateProxyClass("$Proxy11", ServiceImpl.class.getInterfaces());
        FileOutputStream out = null;
try {
            out = new FileOutputStream(path);
            out.write(classFile);
            out.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

1.2 CGlib代理

CGlib动态代理需要cglib的jar包
maven引入

    <dependency>
      <groupId>cglib</groupId>
      <artifactId>cglib</artifactId>
      <version>3.1</version>
    </dependency>

定义一个被代理类

public class SomeClass {
public void doSomething() {
        System.out.println("方法正在执行...");
    }
}

实现cglib的MethodInterceptor

public class CGlibProxy implements MethodInterceptor {
private Object target;

public Object getInstance(Object target) {
this.target = target;
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(this.target.getClass());
        enhancer.setCallback(this);
return enhancer.create();
    }

@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println("..........before..........");
        proxy.invokeSuper(obj, args);
        System.out.println("..........after ..........");
return null;
    }
}

测试类

public class TestCGlib {
public static void main(String[] a) throws Exception {
//输出生成的代理类class文件到指定的目录
        System.setProperty(DebuggingClassWriter.DEBUG_LOCATION_PROPERTY, "E:\\cglib");

        CGlibProxy cglib = new CGlibProxy();
        SomeClass businessObject = (SomeClass) cglib.getInstance(new SomeClass());
// System.out.println(businessObject.getClass().getName());
// System.out.println(businessObject.getClass().getSuperclass().getName());
        businessObject.doSomething();
    }
}

2 代理生成的代理类解析

2.1 JDK代理类

import com.lww.learnjdk.JDKProxy.Service;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.UndeclaredThrowableException;
//看到这就明白为什么JDK只能代理接口了
//JDK动态代理自己就得继承Proxy类，而Java只能单继承
public final class $Proxy11
extends Proxy
implements Service
{
private static Method m1;
private static Method m2;
private static Method m3;
private static Method m0;

public $Proxy11(InvocationHandler paramInvocationHandler)
throws 
  {
super(paramInvocationHandler);
  }

public final boolean equals(Object paramObject)
throws 
  {
try
    {
return ((Boolean)this.h.invoke(this, m1, new Object[] { paramObject })).booleanValue();
    }
catch (Error|RuntimeException localError)
    {
throw localError;
    }
catch (Throwable localThrowable)
    {
throw new UndeclaredThrowableException(localThrowable);
    }
  }

public final String toString()
throws 
  {
try
    {
return (String)this.h.invoke(this, m2, null);
    }
catch (Error|RuntimeException localError)
    {
throw localError;
    }
catch (Throwable localThrowable)
    {
throw new UndeclaredThrowableException(localThrowable);
    }
  }

public final void say()
throws 
  {
try
    {
//m3通过Java反射调用被代理接口的say方法
this.h.invoke(this, m3, null);
return;
    }
catch (Error|RuntimeException localError)
    {
throw localError;
    }
catch (Throwable localThrowable)
    {
throw new UndeclaredThrowableException(localThrowable);
    }
  }

public final int hashCode()
throws 
  {
try
    {
return ((Integer)this.h.invoke(this, m0, null)).intValue();
    }
catch (Error|RuntimeException localError)
    {
throw localError;
    }
catch (Throwable localThrowable)
    {
throw new UndeclaredThrowableException(localThrowable);
    }
  }

static
  {
try
    {
      m1 = Class.forName("java.lang.Object").getMethod("equals", new Class[] { Class.forName("java.lang.Object") });
      m2 = Class.forName("java.lang.Object").getMethod("toString", new Class[0]);
      m3 = Class.forName("com.lww.learnjdk.JDKProxy.Service").getMethod("say", new Class[0]);
      m0 = Class.forName("java.lang.Object").getMethod("hashCode", new Class[0]);
return;
    }
catch (NoSuchMethodException localNoSuchMethodException)
    {
throw new NoSuchMethodError(localNoSuchMethodException.getMessage());
    }
catch (ClassNotFoundException localClassNotFoundException)
    {
throw new NoClassDefFoundError(localClassNotFoundException.getMessage());
    }
  }
}

2.2 CGlib代理类

生成的Class源码，使用jd-gui查看
使用jd-gui查看可能会出现反编译不全的情况。我后面使用procyon-decompiler-0.5.30.jar反编译的
jar地址https://bitbucket.org/mstrobel/procyon/downloads/
命令java -jar procyon-decompiler-0.5.30.jar SomeClass$$EnhancerByCGLIB$.$84389373.class
去掉一个两个$中间的.因为编辑器的原因加上的

package com.lww.learnjdk.CGlibProxy;

import java.lang.reflect.Method;
import net.sf.cglib.core.ReflectUtils;
import net.sf.cglib.core.Signature;
import net.sf.cglib.proxy.Callback;
import net.sf.cglib.proxy.Factory;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class SomeClass$$EnhancerByCGLIB$$84389373
extends SomeClass
implements Factory
{
private boolean CGLIB$BOUND;
private static final ThreadLocal CGLIB$THREAD_CALLBACKS;
private static final Callback[] CGLIB$STATIC_CALLBACKS;
private MethodInterceptor CGLIB$CALLBACK_0;
private static final Method CGLIB$doSomething$0$Method;
private static final MethodProxy CGLIB$doSomething$0$Proxy;
private static final Object[] CGLIB$emptyArgs;
private static final Method CGLIB$finalize$1$Method;
private static final MethodProxy CGLIB$finalize$1$Proxy;
private static final Method CGLIB$equals$2$Method;
private static final MethodProxy CGLIB$equals$2$Proxy;
private static final Method CGLIB$toString$3$Method;
private static final MethodProxy CGLIB$toString$3$Proxy;
private static final Method CGLIB$hashCode$4$Method;
private static final MethodProxy CGLIB$hashCode$4$Proxy;
private static final Method CGLIB$clone$5$Method;
private static final MethodProxy CGLIB$clone$5$Proxy;

static void CGLIB$STATICHOOK1()
  {
    CGLIB$THREAD_CALLBACKS = new ThreadLocal();
    CGLIB$emptyArgs = new Object[0];
    Class localClass1 = Class.forName("com.lww.learnjdk.CGlibProxy.SomeClass$$EnhancerByCGLIB$$84389373");
    Class localClass2;
    Method[] tmp95_92 = ReflectUtils.findMethods(new String[] { "finalize", "()V", "equals", "(Ljava/lang/Object;)Z", "toString", "()Ljava/lang/String;", "hashCode", "()I", "clone", "()Ljava/lang/Object;" }, (localClass2 = Class.forName("java.lang.Object")).getDeclaredMethods());
    CGLIB$finalize$1$Method = tmp95_92[0];
    CGLIB$finalize$1$Proxy = MethodProxy.create(localClass2, localClass1, "()V", "finalize", "CGLIB$finalize$1");
    Method[] tmp115_95 = tmp95_92;
    CGLIB$equals$2$Method = tmp115_95[1];
    CGLIB$equals$2$Proxy = MethodProxy.create(localClass2, localClass1, "(Ljava/lang/Object;)Z", "equals", "CGLIB$equals$2");
    Method[] tmp135_115 = tmp115_95;
    CGLIB$toString$3$Method = tmp135_115[2];
    CGLIB$toString$3$Proxy = MethodProxy.create(localClass2, localClass1, "()Ljava/lang/String;", "toString", "CGLIB$toString$3");
    Method[] tmp155_135 = tmp135_115;
    CGLIB$hashCode$4$Method = tmp155_135[3];
    CGLIB$hashCode$4$Proxy = MethodProxy.create(localClass2, localClass1, "()I", "hashCode", "CGLIB$hashCode$4");
    Method[] tmp175_155 = tmp155_135;
    CGLIB$clone$5$Method = tmp175_155[4];
    CGLIB$clone$5$Proxy = MethodProxy.create(localClass2, localClass1, "()Ljava/lang/Object;", "clone", "CGLIB$clone$5");
    tmp175_155;
    Method[] tmp223_220 = ReflectUtils.findMethods(new String[] { "doSomething", "()V" }, (localClass2 = Class.forName("com.lww.learnjdk.CGlibProxy.SomeClass")).getDeclaredMethods());
    CGLIB$doSomething$0$Method = tmp223_220[0];
    CGLIB$doSomething$0$Proxy = MethodProxy.create(localClass2, localClass1, "()V", "doSomething", "CGLIB$doSomething$0");
    tmp223_220;
return;
  }
//调用父类方法
//在后面会用到
//千万要记得这个方法
final void CGLIB$doSomething$0() {
super.doSomething();
    }   

public final void doSomething() {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
//调用你实现MethodInterceptor的intercept方法
            cglib$CALLBACK_2.intercept((Object)this, SomeClass$$EnhancerByCGLIB$
$84389373.CGLIB$doSomething$0$Method, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB
$emptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$doSomething$0$Proxy);
return;
        }
super.doSomething();
    }

final void CGLIB$finalize$1() throws Throwable {
super.finalize();
    }

protected final void finalize() throws Throwable {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
            cglib$CALLBACK_2.intercept((Object)this, SomeClass$$EnhancerByCGLIB$
$84389373.CGLIB$finalize$1$Method, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$em
ptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$finalize$1$Proxy);
return;
        }
super.finalize();
    }

final boolean CGLIB$equals$2(final Object o) {
return super.equals(o);
    }

public final boolean equals(final Object o) {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
final Object intercept = cglib$CALLBACK_2.intercept((Object)this, So
meClass$$EnhancerByCGLIB$$84389373.CGLIB$equals$2$Method, new Object[] { o }, So
meClass$$EnhancerByCGLIB$$84389373.CGLIB$equals$2$Proxy);
return intercept != null && (boolean)intercept;
        }
return super.equals(o);
    }

final String CGLIB$toString$3() {
return super.toString();
    }

public final String toString() {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
return (String)cglib$CALLBACK_2.intercept((Object)this, SomeClass$$E
nhancerByCGLIB$$84389373.CGLIB$toString$3$Method, SomeClass$$EnhancerByCGLIB$$84
389373.CGLIB$emptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$toString$3$Pr
oxy);
        }
return super.toString();
    }

final int CGLIB$hashCode$4() {
return super.hashCode();
    }

public final int hashCode() {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
final Object intercept = cglib$CALLBACK_2.intercept((Object)this, So
meClass$$EnhancerByCGLIB$$84389373.CGLIB$hashCode$4$Method, SomeClass$$EnhancerB
yCGLIB$$84389373.CGLIB$emptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$has
hCode$4$Proxy);
return (intercept == null) ? 0 : ((Number)intercept).intValue();
        }
return super.hashCode();
    }

final Object CGLIB$clone$5() throws CloneNotSupportedException {
return super.clone();
    }

protected final Object clone() throws CloneNotSupportedException {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
return cglib$CALLBACK_2.intercept((Object)this, SomeClass$$EnhancerB
yCGLIB$$84389373.CGLIB$clone$5$Method, SomeClass$$EnhancerByCGLIB$$84389373.CGLI
B$emptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$clone$5$Proxy);
        }
return super.clone();
    }

public static MethodProxy CGLIB$findMethodProxy(final Signature signature) {

final String string = signature.toString();
switch (string.hashCode()) {
case -1574182249: {
if (string.equals("finalize()V")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$finalize$1
$Proxy;
                }
break;
            }
case -508378822: {
if (string.equals("clone()Ljava/lang/Object;")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$clone$5$Pr
oxy;
                }
break;
            }
case 1826985398: {
if (string.equals("equals(Ljava/lang/Object;)Z")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$equals$2$P
roxy;
                }
break;
            }
case 1913648695: {
if (string.equals("toString()Ljava/lang/String;")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$toString$3
$Proxy;
                }
break;
            }
case 1984935277: {
if (string.equals("hashCode()I")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$hashCode$4
$Proxy;
                }
break;
            }
case 2121560294: {
if (string.equals("doSomething()V")) {
return SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$doSomethin
g$0$Proxy;
                }
break;
            }
        }
return null;
    }

public SomeClass$$EnhancerByCGLIB$$84389373() {
        CGLIB$BIND_CALLBACKS(this);
    }

public static void CGLIB$SET_THREAD_CALLBACKS(final Callback[] array) {
        SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$THREAD_CALLBACKS.set(array);
    }

public static void CGLIB$SET_STATIC_CALLBACKS(final Callback[] cglib$STATIC_
CALLBACKS) {
        CGLIB$STATIC_CALLBACKS = cglib$STATIC_CALLBACKS;
    }

private static final void CGLIB$BIND_CALLBACKS(final Object o) {
final SomeClass$$EnhancerByCGLIB$$84389373 someClass$$EnhancerByCGLIB$$8
4389373 = (SomeClass$$EnhancerByCGLIB$$84389373)o;
if (!someClass$$EnhancerByCGLIB$$84389373.CGLIB$BOUND) {
            someClass$$EnhancerByCGLIB$$84389373.CGLIB$BOUND = true;
            Object o2;
if ((o2 = SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$THREAD_CALLBACK
S.get()) != null || (o2 = SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$STATIC_CALL
BACKS) != null) {
                someClass$$EnhancerByCGLIB$$84389373.CGLIB$CALLBACK_0 = (MethodI
nterceptor)((Callback[])o2)[0];
            }
        }
    }

public Object newInstance(final Callback[] array) {
        CGLIB$SET_THREAD_CALLBACKS(array);
final SomeClass$$EnhancerByCGLIB$$84389373 someClass$$EnhancerByCGLIB$$8
4389373 = new SomeClass$$EnhancerByCGLIB$$84389373();
        CGLIB$SET_THREAD_CALLBACKS(null);
return someClass$$EnhancerByCGLIB$$84389373;
    }

public Object newInstance(final Callback callback) {
        CGLIB$SET_THREAD_CALLBACKS(new Callback[] { callback });
final SomeClass$$EnhancerByCGLIB$$84389373 someClass$$EnhancerByCGLIB$$8
4389373 = new SomeClass$$EnhancerByCGLIB$$84389373();
        CGLIB$SET_THREAD_CALLBACKS(null);
return someClass$$EnhancerByCGLIB$$84389373;
    }

public Object newInstance(final Class[] array, final Object[] array2, final
Callback[] array3) {
        CGLIB$SET_THREAD_CALLBACKS(array3);
switch (array.length) {
case 0: {
final SomeClass$$EnhancerByCGLIB$$84389373 someClass$$EnhancerBy
CGLIB$$84389373 = new SomeClass$$EnhancerByCGLIB$$84389373();
                CGLIB$SET_THREAD_CALLBACKS(null);
return someClass$$EnhancerByCGLIB$$84389373;
            }
default: {
throw new IllegalArgumentException("Constructor not found");
            }
        }
    }

public Callback getCallback(final int n) {
        CGLIB$BIND_CALLBACKS(this);
        Object cglib$CALLBACK_0 = null;
switch (n) {
case 0: {
                cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0;
break;
            }
default: {
                cglib$CALLBACK_0 = null;
break;
            }
        }
return (Callback)cglib$CALLBACK_0;
    }

public void setCallback(final int n, final Callback callback) {
switch (n) {
case 0: {
this.CGLIB$CALLBACK_0 = (MethodInterceptor)callback;
break;
            }
        }
    }

public Callback[] getCallbacks() {
        CGLIB$BIND_CALLBACKS(this);
return new Callback[] { this.CGLIB$CALLBACK_0 };
    }

public void setCallbacks(final Callback[] array) {
this.CGLIB$CALLBACK_0 = (MethodInterceptor)array[0];
    }

static {
        CGLIB$STATICHOOK1();
    }
}

3 两种方式解析

前面已经知道怎么实现，看了完整的源码。现在看怎么实现以及调用过程

3.1 CGlib代理解析

1、创建
在TestCGlib调用CGlibProxy的getInstance方法

        SomeClass businessObject = (SomeClass) cglib.getInstance(new SomeClass());

CGlibProxy的getInstance方法

    public Object getInstance(Object target) {
this.target = target;
        Enhancer enhancer = new Enhancer();
//设置父类
        enhancer.setSuperclass(this.target.getClass());
//用来生成的代理类回调intercept()方法
//在生成的代理类源码有判断
        enhancer.setCallback(this);
//主要
return enhancer.create();
    }

Enhancer的create方法

    public Object create() {
this.classOnly = false;
this.argumentTypes = null;
return this.createHelper();
    }

Enhancer的createHelper方法

    private Object createHelper() {
this.validate();
if(this.superclass != null) {
this.setNamePrefix(this.superclass.getName());
        } else if(this.interfaces != null) {
this.setNamePrefix(this.interfaces[ReflectUtils.findPackageProtected(this.interfaces)].getName());
        }
//调用父类AbstractClassGenerator生成代理类
return super.create(KEY_FACTORY.newInstance(this.superclass != null?this.superclass.getName():null, ReflectUtils.getNames(this.interfaces), this.filter, this.callbackTypes, this.useFactory, this.interceptDuringConstruction, this.serialVersionUID));
    }

具体怎么生成我也看不太懂<.-.>
2、调用
在TestCGlib中

//此处businessObject已经是代理类了
businessObject.doSomething();

代理类的doSomething方法查看源码

    public final void doSomething() {
        MethodInterceptor cglib$CALLBACK_2;
        MethodInterceptor cglib$CALLBACK_0;
if ((cglib$CALLBACK_0 = (cglib$CALLBACK_2 = this.CGLIB$CALLBACK_0)) == n
ull) {
            CGLIB$BIND_CALLBACKS(this);
            cglib$CALLBACK_2 = (cglib$CALLBACK_0 = this.CGLIB$CALLBACK_0);
        }
if (cglib$CALLBACK_0 != null) {
//调用CGlibProxy的intercept方法
//参数1、代理对象；2、委托类方法；3、方法参数；4、代理方法的MethodProxy对象。
            cglib$CALLBACK_2.intercept((Object)this, SomeClass$$EnhancerByCGLIB$
$84389373.CGLIB$doSomething$0$Method, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB
$emptyArgs, SomeClass$$EnhancerByCGLIB$$84389373.CGLIB$doSomething$0$Proxy);
return;
        }
super.doSomething();
    }

CGlibProxy的intercept方法

    @Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
//这里只是调用输出的前后消息并没有执行被调类的方法
        System.out.println("..........before..........");
//进入这个函数
        proxy.invokeSuper(obj, args);
        System.out.println("..........after ..........");
return null;
    }

MethodProxy的invokeSuper方法

//这里面就是关键
public Object invokeSuper(Object obj, Object[] args) throws Throwable {
try {
this.init();
            MethodProxy.FastClassInfo fci = this.fastClassInfo;
//f2是由CGlib生成的在输出的class中有
//SomeClass$$EnhancerByCGLIB$$831e1f52$$FastClassByCGLIB$$513605b2.class
return fci.f2.invoke(fci.i2, obj, args);
        } catch (InvocationTargetException var4) {
throw var4.getTargetException();
        }
    }

查看f2.invoke方法

    public Object invoke(final int n, final Object o, final Object[] array) thro
ws InvocationTargetException {
final SomeClass$$EnhancerByCGLIB$$831e1f52 someClass$$EnhancerByCGLIB$$8
31e1f52 = (SomeClass$$EnhancerByCGLIB$$831e1f52)o;
try {
switch (n) {
case 0: {
return new Boolean(someClass$$EnhancerByCGLIB$$831e1f52.equa
ls(array[0]));
                }
case 1: {
return someClass$$EnhancerByCGLIB$$831e1f52.toString();
                }
case 2: {
return new Integer(someClass$$EnhancerByCGLIB$$831e1f52.hash
Code());
                }
case 3: {
return someClass$$EnhancerByCGLIB$$831e1f52.newInstance((Cla
ss[])array[0], (Object[])array[1], (Callback[])array[2]);
                }
case 4: {
return someClass$$EnhancerByCGLIB$$831e1f52.newInstance((Cal
lback)array[0]);
                }
case 5: {
return someClass$$EnhancerByCGLIB$$831e1f52.newInstance((Cal
lback[])array[0]);
                }
case 6: {
                    someClass$$EnhancerByCGLIB$$831e1f52.setCallbacks((Callback[
])array[0]);
return null;
                }
case 7: {
                    someClass$$EnhancerByCGLIB$$831e1f52.setCallback(((Number)ar
ray[0]).intValue(), (Callback)array[1]);
return null;
                }
case 8: {
                    someClass$$EnhancerByCGLIB$$831e1f52.doSomething();
return null;
                }
case 9: {
return someClass$$EnhancerByCGLIB$$831e1f52.getCallback(((Nu
mber)array[0]).intValue());
                }
case 10: {
return someClass$$EnhancerByCGLIB$$831e1f52.getCallbacks();
                }
case 11: {
                    SomeClass$$EnhancerByCGLIB$$831e1f52.CGLIB$SET_STATIC_CALLBA
CKS((Callback[])array[0]);
return null;
                }
case 12: {
                    SomeClass$$EnhancerByCGLIB$$831e1f52.CGLIB$SET_THREAD_CALLBA
CKS((Callback[])array[0]);
return null;
                }
case 13: {
return new Boolean(someClass$$EnhancerByCGLIB$$831e1f52.CGLI
B$equals$2(array[0]));
                }
case 14: {
                    someClass$$EnhancerByCGLIB$$831e1f52.CGLIB$finalize$1();
return null;
                }
case 15: {
return someClass$$EnhancerByCGLIB$$831e1f52.CGLIB$toString$3
();
                }
case 16: {
return new Integer(someClass$$EnhancerByCGLIB$$831e1f52.CGLI
B$hashCode$4());
                }
case 17: {
return someClass$$EnhancerByCGLIB$$831e1f52.CGLIB$clone$5();

                }
case 18: {
return SomeClass$$EnhancerByCGLIB$$831e1f52.CGLIB$findMethod
Proxy((Signature)array[0]);
                }
case 19: {
                    SomeClass$$EnhancerByCGLIB$$831e1f52.CGLIB$STATICHOOK1();
return null;
                }
case 20: {
//看到这doSomething$0方法是不是很惊喜。没错就是调用父类doSomething。
//前面的一串someClass$$EnhancerByCGLIB$$831e1f52是CGlib生成的代理类
//那么会不会走这个方法呢。我们调试就知道了，记住case 20！！！
                    someClass$$EnhancerByCGLIB$$831e1f52.CGLIB$doSomething$0();
return null;
                }
case 21: {
                    someClass$$EnhancerByCGLIB$$831e1f52.wait();
return null;
                }
case 22: {
                    someClass$$EnhancerByCGLIB$$831e1f52.wait(((Number)array[0])
.longValue(), ((Number)array[1]).intValue());
return null;
                }
case 23: {
                    someClass$$EnhancerByCGLIB$$831e1f52.wait(((Number)array[0])
.longValue());
return null;
                }
case 24: {
return someClass$$EnhancerByCGLIB$$831e1f52.getClass();
                }
case 25: {
                    someClass$$EnhancerByCGLIB$$831e1f52.notify();
return null;
                }
case 26: {
                    someClass$$EnhancerByCGLIB$$831e1f52.notifyAll();
return null;
                }
            }
        }
catch (Throwable t) {
throw new InvocationTargetException(t);
        }
throw new IllegalArgumentException("Cannot find matching method/construc
tor");
    }

CGlib与JDK动态代理
我们看到直接就是20。
进入case 20调用父类的方法，然后就返回到CGlibProxy的intercept方法，因为还有最后一句after没有输出啊！

    @Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println("..........before..........");
        proxy.invokeSuper(obj, args);
        System.out.println("..........after ..........");
return null;
    }

最后就结束了！

3.2 JDK动态代理解析

1、生成代理类
TestJDKProxy

        // 实例化目标对象
        Service userService = new ServiceImpl();
// 实例化InvocationHandler
        JDKInvocationHandler invocationHandler = new JDKInvocationHandler(userService);
// 根据目标对象生成代理对象
        Service proxy = (Service) invocationHandler.getProxy();

跟入getProxy方法(JDKInvocationHandler类)

    public Object getProxy() {
return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
                target.getClass().getInterfaces(), this);
    }

生成部分还是等我看懂了，再来补充吧
2、调用
TestJDKProxy中

    // 已经是代理类了
// 调用代理对象的方法
        proxy.say();

查看代理类

  public final void say()
throws 
  {
try
    {
this.h.invoke(this, m3, null);
return;
    }
catch (Error|RuntimeException localError)
    {
throw localError;
    }
catch (Throwable localThrowable)
    {
throw new UndeclaredThrowableException(localThrowable);
    }
  }
//在静态方法执行的。
m3 = Class.forName("com.lww.learnjdk.JDKProxy.Service").getMethod("say", new Class[0]);

回到JDKInvocationHandler类查看invoke方法

    @Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("------------------before------------------");
        Object result = method.invoke(target, args);
        System.out.println("-------------------after------------------");

return result;
    }

Method的invoke方法
到这再往下就是java反射（方法）的源码了

    public Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException,
           InvocationTargetException
    {
if (!override) {
if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
                Class<?> caller = Reflection.getCallerClass();
                checkAccess(caller, clazz, obj, modifiers);
            }
        }
        MethodAccessor ma = methodAccessor;             // read volatile
if (ma == null) {
            ma = acquireMethodAccessor();
        }
//执行这句
return ma.invoke(obj, args);
    }

MethodAccessor 类继承结构图
CGlib与JDK动态代理
具体执行方法是 DelegatingMethodAccessorImpl

    private MethodAccessorImpl delegate;

public Object invoke(Object var1, Object[] var2) throws IllegalArgumentException, InvocationTargetException {
return this.delegate.invoke(var1, var2);
    }

NativeMethodAccessorImpl的invoke方法

    public Object invoke(Object var1, Object[] var2) throws IllegalArgumentException, InvocationTargetException {
if(++this.numInvocations > ReflectionFactory.inflationThreshold() && !ReflectUtil.isVMAnonymousClass(this.method.getDeclaringClass())) {
            MethodAccessorImpl var3 = (MethodAccessorImpl)(new MethodAccessorGenerator()).generateMethod(this.method.getDeclaringClass(), this.method.getName(), this.method.getParameterTypes(), this.method.getReturnType(), this.method.getExceptionTypes(), this.method.getModifiers());
this.parent.setDelegate(var3);
        }
//调用本地方法
return invoke0(this.method, var1, var2);
    }
//本地方法执行方法
private static native Object invoke0(Method var0, Object var1, Object[] var2);

调用ServiceImpl的say方法

    @Override
public void say() {
        System.out.println("Hello JDK");
    }

4 总结

4.1 JDK动态代理

1、生成代理类快，因为方法调用交给Java反射做了
2、只能面向接口，因为代理类默认继承Proxy类
3、不需要其他jar包

4.2 CGlib动态代理

优点：
1、执行速度快，因为CGlib生成代理类的时候会将被代理类的方法进行编号，直接传入编号就调用了。
2、可以为没有接口的类进行动态代理
劣势：
1、就因为它要编号所以它生成代理类的速度比较慢。尤其是需要多次生成代理类的时候。
2、因为是继承关系所以如果父类的final方法它就无能为力了

5 补充

参考资料：
http://blog.csdn.net/tiandesheng111/article/details/39833901
http://www.cnblogs.com/chinajava/p/5880870.html
http://www.cnblogs.com/chinajava/p/5880887.html
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