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Cglib代理解密
发布日期：2022-02-26 14:49:34 浏览次数：53 分类：技术文章

本文共 44312 字，大约阅读时间需要 147 分钟。

Cglib代理原理解密

cglib与动态代理功能类似，都是为了做方法拦截的，从而增强方法功能，本文讲解cglib的原理

我有一个CglibDemo类，也就是main方法的测试类, 他有一个属性name和他的get set方法

import net.sf.cglib.core.DebuggingClassWriter;import net.sf.cglib.proxy.Enhancer;import net.sf.cglib.proxy.MethodInterceptor;import net.sf.cglib.proxy.MethodProxy;import java.lang.reflect.Method;/** * @author hh * @date 2020/9/29 */public class CglibDemo {
       public static void main(String[] args) throws Exception{
           System.setProperty(DebuggingClassWriter.DEBUG_LOCATION_PROPERTY, "c:\\classes");        Enhancer enhancer = new Enhancer();        enhancer.setSuperclass(CglibDemo.class);        enhancer.setCallback(new MethodInterceptor() {
               @Override            public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
                   System.out.println("before...");                Object result = proxy.invokeSuper(obj, args);                System.out.println("after ...");                return result;            }        });        CglibDemo cglibProxy = (CglibDemo) enhancer.create();        cglibProxy.getName();    }    private String name;    public String getName() {
           System.out.println("get name...");        return name;    }    public void setName(String name) {
           System.out.println("set name...");        this.name = name;    }}

我想在setName和getName方法被调用之前打印"before" 之后打印"after", 运行以上main方法成功打印:

before...get name...after ...

cglib代理一共生成了三个class,使用的是asm框架在内存中动态生成的，他们分别是:

CglibDemo$$EnhancerByCGLIB$$1a76a66CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752CglibDemo$$FastClassByCGLIB$$4320d206

1.先讲解 CglibDemo$$EnhancerByCGLIB$$1a76a66

  • 这个类是我们CglibDemo cglibProxy = (CglibDemo) enhancer.create();获得的代理类，他不是FastClass类
  • 注意他的名字中没有FastClass字眼
  • 因为enhancer.setSuperclass(CglibDemo.class),所以他是CglibDemo的子类，而且名字中也带有CglibDemo字眼
  • 这个类的内容如下:
/** * 这个类是从内存中使用hsdb工具弄下来，再使用idea反编译，然后手动修改其中的编译错误而来的 
 * * 这个类是代理类,是cglib生成的CglibDemo子类 */import lombok.SneakyThrows;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;import java.lang.reflect.Method;public class CglibDemo$$EnhancerByCGLIB$$1a76a66 extends CglibDemo implements Factory {
       private boolean CGLIB$BOUND;    public static Object CGLIB$FACTORY_DATA;    private static ThreadLocal CGLIB$THREAD_CALLBACKS;    private static Callback[] CGLIB$STATIC_CALLBACKS;    private MethodInterceptor CGLIB$CALLBACK_0;    private static Object CGLIB$CALLBACK_FILTER;    private static Method CGLIB$getName$0$Method;    private static MethodProxy CGLIB$getName$0$Proxy;    private static Object[] CGLIB$emptyArgs;    private static Method CGLIB$setName$1$Method;    private static MethodProxy CGLIB$setName$1$Proxy;    private static Method CGLIB$equals$2$Method;    private static MethodProxy CGLIB$equals$2$Proxy;    private static Method CGLIB$toString$3$Method;    private static MethodProxy CGLIB$toString$3$Proxy;    private static Method CGLIB$hashCode$4$Method;    private static MethodProxy CGLIB$hashCode$4$Proxy;    private static Method CGLIB$clone$5$Method;    private static MethodProxy CGLIB$clone$5$Proxy;    public CglibDemo$$EnhancerByCGLIB$$1a76a66() {
           CGLIB$BIND_CALLBACKS(this);    }    static {
           CGLIB$STATICHOOK1();    }    @SneakyThrows    public final boolean equals(Object var1) {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        if (var10000 != null) {
               Object var2 = var10000.intercept(this, CGLIB$equals$2$Method, new Object[]{
   var1}, CGLIB$equals$2$Proxy);            return var2 == null ? false : (Boolean)var2;        } else {
               return super.equals(var1);        }    }    @SneakyThrows    public final String toString() {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        return var10000 != null ? (String)var10000.intercept(this, CGLIB$toString$3$Method, CGLIB$emptyArgs, CGLIB$toString$3$Proxy) : super.toString();    }    @SneakyThrows    public final int hashCode() {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        if (var10000 != null) {
               Object var1 = var10000.intercept(this, CGLIB$hashCode$4$Method, CGLIB$emptyArgs, CGLIB$hashCode$4$Proxy);            return var1 == null ? 0 : ((Number)var1).intValue();        } else {
               return super.hashCode();        }    }    @SneakyThrows    protected final Object clone() throws CloneNotSupportedException {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        return var10000 != null ? var10000.intercept(this, CGLIB$clone$5$Method, CGLIB$emptyArgs, CGLIB$clone$5$Proxy) : super.clone();    }    @SneakyThrows    public final String getName() {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        return var10000 != null ? (String)var10000.intercept(this, CGLIB$getName$0$Method, CGLIB$emptyArgs, CGLIB$getName$0$Proxy) : super.getName();    }    public Object newInstance(Class[] var1, Object[] var2, Callback[] var3) {
           CGLIB$SET_THREAD_CALLBACKS(var3);        CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = new CglibDemo$$EnhancerByCGLIB$$1a76a66();        switch(var1.length) {
               case 0:                // var10000.
   
    ();                CGLIB$SET_THREAD_CALLBACKS((Callback[])null);                return var10000;            default:                throw new IllegalArgumentException("Constructor not found");        }    }    public Object newInstance(Callback var1) {
           CGLIB$SET_THREAD_CALLBACKS(new Callback[]{
   var1});        CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = new CglibDemo$$EnhancerByCGLIB$$1a76a66();        CGLIB$SET_THREAD_CALLBACKS((Callback[])null);        return var10000;    }    public Object newInstance(Callback[] var1) {
           CGLIB$SET_THREAD_CALLBACKS(var1);        CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = new CglibDemo$$EnhancerByCGLIB$$1a76a66();        CGLIB$SET_THREAD_CALLBACKS((Callback[])null);        return var10000;    }    @SneakyThrows    public final void setName(String var1) {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        if (var10000 != null) {
               var10000.intercept(this, CGLIB$setName$1$Method, new Object[]{
   var1}, CGLIB$setName$1$Proxy);        } else {
               super.setName(var1);        }    }    public void setCallbacks(Callback[] var1) {
           this.CGLIB$CALLBACK_0 = (MethodInterceptor)var1[0];    }    public void setCallback(int var1, Callback var2) {
           switch(var1) {
               case 0:                this.CGLIB$CALLBACK_0 = (MethodInterceptor)var2;            default:        }    }    public Callback[] getCallbacks() {
           CGLIB$BIND_CALLBACKS(this);        return new Callback[]{
   this.CGLIB$CALLBACK_0};    }    public Callback getCallback(int var1) {
           CGLIB$BIND_CALLBACKS(this);        MethodInterceptor var10000;        switch(var1) {
               case 0:                var10000 = this.CGLIB$CALLBACK_0;                break;            default:                var10000 = null;        }        return var10000;    }    public static void CGLIB$SET_THREAD_CALLBACKS(Callback[] var0) {
           CGLIB$THREAD_CALLBACKS.set(var0);    }    public static void CGLIB$SET_STATIC_CALLBACKS(Callback[] var0) {
           CGLIB$STATIC_CALLBACKS = var0;    }    public static MethodProxy CGLIB$findMethodProxy(Signature var0) {
           String var10000 = var0.toString();        switch(var10000.hashCode()) {
               case -1184972270:                if (var10000.equals("setName(Ljava/lang/String;)V")) {
                       return CGLIB$setName$1$Proxy;                }                break;            case -508378822:                if (var10000.equals("clone()Ljava/lang/Object;")) {
                       return CGLIB$clone$5$Proxy;                }                break;            case 1218144844:                if (var10000.equals("getName()Ljava/lang/String;")) {
                       return CGLIB$getName$0$Proxy;                }                break;            case 1826985398:                if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
                       return CGLIB$equals$2$Proxy;                }                break;            case 1913648695:                if (var10000.equals("toString()Ljava/lang/String;")) {
                       return CGLIB$toString$3$Proxy;                }                break;            case 1984935277:                if (var10000.equals("hashCode()I")) {
                       return CGLIB$hashCode$4$Proxy;                }        }        return null;    }    @SneakyThrows    static void CGLIB$STATICHOOK1() {
           CGLIB$THREAD_CALLBACKS = new ThreadLocal();        CGLIB$emptyArgs = new Object[0];        Class var0 = Class.forName("hh.proxy.cglib.CglibDemo$$EnhancerByCGLIB$$1a76a66");        Class var1;        Method[] var10000 = ReflectUtils.findMethods(new String[]{
   "equals", "(Ljava/lang/Object;)Z", "toString", "()Ljava/lang/String;", "hashCode", "()I", "clone", "()Ljava/lang/Object;"}, (var1 = Class.forName("java.lang.Object")).getDeclaredMethods());        CGLIB$equals$2$Method = var10000[0];        CGLIB$equals$2$Proxy = MethodProxy.create(var1, var0, "(Ljava/lang/Object;)Z", "equals", "CGLIB$equals$2");        CGLIB$toString$3$Method = var10000[1];        CGLIB$toString$3$Proxy = MethodProxy.create(var1, var0, "()Ljava/lang/String;", "toString", "CGLIB$toString$3");        CGLIB$hashCode$4$Method = var10000[2];        CGLIB$hashCode$4$Proxy = MethodProxy.create(var1, var0, "()I", "hashCode", "CGLIB$hashCode$4");        CGLIB$clone$5$Method = var10000[3];        CGLIB$clone$5$Proxy = MethodProxy.create(var1, var0, "()Ljava/lang/Object;", "clone", "CGLIB$clone$5");        var10000 = ReflectUtils.findMethods(new String[]{
   "getName", "()Ljava/lang/String;", "setName", "(Ljava/lang/String;)V"}, (var1 = Class.forName("hh.proxy.cglib.CglibDemo")).getDeclaredMethods());        CGLIB$getName$0$Method = var10000[0];        CGLIB$getName$0$Proxy = MethodProxy.create(var1, var0, "()Ljava/lang/String;", "getName", "CGLIB$getName$0");        CGLIB$setName$1$Method = var10000[1];        CGLIB$setName$1$Proxy = MethodProxy.create(var1, var0, "(Ljava/lang/String;)V", "setName", "CGLIB$setName$1");    }    private static final void CGLIB$BIND_CALLBACKS(Object var0) {
           CglibDemo$$EnhancerByCGLIB$$1a76a66 var1 = (CglibDemo$$EnhancerByCGLIB$$1a76a66)var0;        if (!var1.CGLIB$BOUND) {
               var1.CGLIB$BOUND = true;            Object var10000 = CGLIB$THREAD_CALLBACKS.get();            if (var10000 == null) {
                   var10000 = CGLIB$STATIC_CALLBACKS;                if (var10000 == null) {
                       return;                }            }            var1.CGLIB$CALLBACK_0 = (MethodInterceptor)((Callback[])var10000)[0];        }    }    final int CGLIB$hashCode$4() {
           return super.hashCode();    }    final String CGLIB$toString$3() {
           return super.toString();    }    final String CGLIB$getName$0() {
           return super.getName();    }    final boolean CGLIB$equals$2(Object var1) {
           return super.equals(var1);    }    final void CGLIB$setName$1(String var1) {
           super.setName(var1);    }    final Object CGLIB$clone$5() throws CloneNotSupportedException {
           return super.clone();    }}

2. 类CglibDemo$$FastClassByCGLIB$$4320d206

  • 这个类是一个FastClass类
  • 注意他的名字中有FastClass字眼
  • 他是一个FastClass1类, 至于为什么说他是1, 待会解密
  • 这个类的内容如下:
/** * 这个类是从内存中使用hsdb工具弄下来，再使用idea反编译，然后手动修改其中的编译错误而来的 
 * * 这个类是一个FastClass,而且他是FastClass1 * @author hh * @date 2020/9/29 */import net.sf.cglib.core.Signature;import net.sf.cglib.reflect.FastClass;import java.lang.reflect.InvocationTargetException;public class CglibDemo$$FastClassByCGLIB$$4320d206 extends FastClass {
       public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
           CglibDemo var10000 = (CglibDemo)var2;        int var10001 = var1;        try {
               switch(var10001) {
                   case 0:                    CglibDemo.main((String[])var3[0]);                    return null;                case 1:                    return var10000.getName();                case 2:                    var10000.setName((String)var3[0]);                    return null;                case 3:                    return new Boolean(var10000.equals(var3[0]));                case 4:                    return var10000.toString();                case 5:                    return new Integer(var10000.hashCode());            }        } catch (Throwable var4) {
               throw new InvocationTargetException(var4);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }    public CglibDemo$$FastClassByCGLIB$$4320d206(Class var1) {
           super(var1);    }    public Object newInstance(int var1, Object[] var2) throws InvocationTargetException {
           CglibDemo var10000 = new CglibDemo();        CglibDemo var10001 = var10000;        int var10002 = var1;        try {
               switch(var10002) {
                   case 0:                    // var10001.
   
    ();                    return var10000;            }        } catch (Throwable var3) {
               throw new InvocationTargetException(var3);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }    public int getIndex(Class[] var1) {
           switch(var1.length) {
               case 0:                return 0;            default:                return -1;        }    }    public int getIndex(String var1, Class[] var2) {
           switch(var1.hashCode()) {
               case -1776922004:                if (var1.equals("toString")) {
                       switch(var2.length) {
                           case 0:                            return 4;                    }                }                break;            case -1295482945:                if (var1.equals("equals")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.Object")) {
                                   return 3;                            }                    }                }                break;            case -75308287:                if (var1.equals("getName")) {
                       switch(var2.length) {
                           case 0:                            return 1;                    }                }                break;            case 3343801:                if (var1.equals("main")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("[Ljava.lang.String;")) {
                                   return 0;                            }                    }                }                break;            case 147696667:                if (var1.equals("hashCode")) {
                       switch(var2.length) {
                           case 0:                            return 5;                    }                }                break;            case 1984801293:                if (var1.equals("setName")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.String")) {
                                   return 2;                            }                    }                }        }        return -1;    }    public int getIndex(Signature var1) {
           String var10000 = var1.toString();        switch(var10000.hashCode()) {
               case -1184972270:                if (var10000.equals("setName(Ljava/lang/String;)V")) {
                       return 2;                }                break;            case 1218144844:                if (var10000.equals("getName()Ljava/lang/String;")) {
                       return 1;                }                break;            case 1341835395:                if (var10000.equals("main([Ljava/lang/String;)V")) {
                       return 0;                }                break;            case 1826985398:                if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
                       return 3;                }                break;            case 1913648695:                if (var10000.equals("toString()Ljava/lang/String;")) {
                       return 4;                }                break;            case 1984935277:                if (var10000.equals("hashCode()I")) {
                       return 5;                }        }        return -1;    }    public int getMaxIndex() {
           return 5;    }}

3. 类CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752

  • 这个类是一个的名字有点长, 他是一个FastClass类
  • 注意他的名字中有FastClass字眼
  • 他是一个FastClass2类, 至于为什么说他是2, 待会解密
  • 这个类的内容如下:
/** * 这个类是从内存中使用hsdb工具弄下来，再使用idea反编译，然后手动修改其中的编译错误而来的 
 * * 这个类是一个FastClass,而且他是FastClass2 * @author hh * @date 2020/9/29 */import net.sf.cglib.core.Signature;import net.sf.cglib.proxy.Callback;import net.sf.cglib.reflect.FastClass;import java.lang.reflect.InvocationTargetException;public class CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752 extends FastClass {
       public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
           CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = (CglibDemo$$EnhancerByCGLIB$$1a76a66)var2;        int var10001 = var1;        try {
               switch(var10001) {
                   case 0:                    return new Boolean(var10000.equals(var3[0]));                case 1:                    return var10000.toString();                case 2:                    return new Integer(var10000.hashCode());                case 3:                    return var10000.clone();                case 4:                    return var10000.getName();                case 5:                    return var10000.newInstance((Class[])var3[0], (Object[])var3[1], (Callback[])var3[2]);                case 6:                    return var10000.newInstance((Callback)var3[0]);                case 7:                    return var10000.newInstance((Callback[])var3[0]);                case 8:                    var10000.setName((String)var3[0]);                    return null;                case 9:                    var10000.setCallbacks((Callback[])var3[0]);                    return null;                case 10:                    var10000.setCallback(((Number)var3[0]).intValue(), (Callback)var3[1]);                    return null;                case 11:                    return var10000.getCallbacks();                case 12:                    return var10000.getCallback(((Number)var3[0]).intValue());                case 13:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$SET_THREAD_CALLBACKS((Callback[])var3[0]);                    return null;                case 14:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$SET_STATIC_CALLBACKS((Callback[])var3[0]);                    return null;                case 15:                    return CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$findMethodProxy((Signature)var3[0]);                case 16:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$STATICHOOK1();                    return null;                case 17:                    return new Integer(var10000.CGLIB$hashCode$4());                case 18:                    return var10000.CGLIB$toString$3();                case 19:                    return var10000.CGLIB$getName$0();                case 20:                    return new Boolean(var10000.CGLIB$equals$2(var3[0]));                case 21:                    var10000.CGLIB$setName$1((String)var3[0]);                    return null;                case 22:                    return var10000.CGLIB$clone$5();                case 23:                    CglibDemo.main((String[])var3[0]);                    return null;            }        } catch (Throwable var4) {
               throw new InvocationTargetException(var4);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }    public CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752(Class var1) {
           super(var1);    }    public Object newInstance(int var1, Object[] var2) throws InvocationTargetException {
           CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = new CglibDemo$$EnhancerByCGLIB$$1a76a66();        CglibDemo$$EnhancerByCGLIB$$1a76a66 var10001 = var10000;        int var10002 = var1;        try {
               switch(var10002) {
                   case 0:                    // var10001.
   
    ();                    return var10000;            }        } catch (Throwable var3) {
               throw new InvocationTargetException(var3);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }    public int getIndex(Class[] var1) {
           switch(var1.length) {
               case 0:                return 0;            default:                return -1;        }    }    public int getIndex(String var1, Class[] var2) {
           switch(var1.hashCode()) {
               case -1776922004:                if (var1.equals("toString")) {
                       switch(var2.length) {
                           case 0:                            return 1;                    }                }                break;            case -1295482945:                if (var1.equals("equals")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.Object")) {
                                   return 0;                            }                    }                }                break;            case -1053468136:                if (var1.equals("getCallbacks")) {
                       switch(var2.length) {
                           case 0:                            return 11;                    }                }                break;            case -124978608:                if (var1.equals("CGLIB$equals$2")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.Object")) {
                                   return 20;                            }                    }                }                break;            case -75308287:                if (var1.equals("getName")) {
                       switch(var2.length) {
                           case 0:                            return 4;                    }                }                break;            case -60403779:                if (var1.equals("CGLIB$SET_STATIC_CALLBACKS")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
                                   return 14;                            }                    }                }                break;            case -29025554:                if (var1.equals("CGLIB$hashCode$4")) {
                       switch(var2.length) {
                           case 0:                            return 17;                    }                }                break;            case 3343801:                if (var1.equals("main")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("[Ljava.lang.String;")) {
                                   return 23;                            }                    }                }                break;            case 5451255:                if (var1.equals("CGLIB$setName$1")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.String")) {
                                   return 21;                            }                    }                }                break;            case 85179481:                if (var1.equals("CGLIB$SET_THREAD_CALLBACKS")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
                                   return 13;                            }                    }                }                break;            case 94756189:                if (var1.equals("clone")) {
                       switch(var2.length) {
                           case 0:                            return 3;                    }                }                break;            case 147696667:                if (var1.equals("hashCode")) {
                       switch(var2.length) {
                           case 0:                            return 2;                    }                }                break;            case 161998109:                if (var1.equals("CGLIB$STATICHOOK1")) {
                       switch(var2.length) {
                           case 0:                            return 16;                    }                }                break;            case 220068330:                if (var1.equals("CGLIB$getName$0")) {
                       switch(var2.length) {
                           case 0:                            return 19;                    }                }                break;            case 495524492:                if (var1.equals("setCallbacks")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
                                   return 9;                            }                    }                }                break;            case 1154623345:                if (var1.equals("CGLIB$findMethodProxy")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("net.sf.cglib.core.Signature")) {
                                   return 15;                            }                    }                }                break;            case 1543336190:                if (var1.equals("CGLIB$toString$3")) {
                       switch(var2.length) {
                           case 0:                            return 18;                    }                }                break;            case 1811874389:                if (var1.equals("newInstance")) {
                       switch(var2.length) {
                           case 1:                            String var10001 = var2[0].getName();                            switch(var10001.hashCode()) {
                                   case -845341380:                                    if (var10001.equals("net.sf.cglib.proxy.Callback")) {
                                           return 6;                                    }                                    break;                                case 1730110032:                                    if (var10001.equals("[Lnet.sf.cglib.proxy.Callback;")) {
                                           return 7;                                    }                            }                        case 2:                        default:                            break;                        case 3:                            if (var2[0].getName().equals("[Ljava.lang.Class;") && var2[1].getName().equals("[Ljava.lang.Object;") && var2[2].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
                                   return 5;                            }                    }                }                break;            case 1817099975:                if (var1.equals("setCallback")) {
                       switch(var2.length) {
                           case 2:                            if (var2[0].getName().equals("int") && var2[1].getName().equals("net.sf.cglib.proxy.Callback")) {
                                   return 10;                            }                    }                }                break;            case 1905679803:                if (var1.equals("getCallback")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("int")) {
                                   return 12;                            }                    }                }                break;            case 1951977611:                if (var1.equals("CGLIB$clone$5")) {
                       switch(var2.length) {
                           case 0:                            return 22;                    }                }                break;            case 1984801293:                if (var1.equals("setName")) {
                       switch(var2.length) {
                           case 1:                            if (var2[0].getName().equals("java.lang.String")) {
                                   return 8;                            }                    }                }        }        return -1;    }    public int getIndex(Signature var1) {
           String var10000 = var1.toString();        switch(var10000.hashCode()) {
               case -2055565910:                if (var10000.equals("CGLIB$SET_THREAD_CALLBACKS([Lnet/sf/cglib/proxy/Callback;)V")) {
                       return 13;                }                break;            case -1457535688:                if (var10000.equals("CGLIB$STATICHOOK1()V")) {
                       return 16;                }                break;            case -1411812934:                if (var10000.equals("CGLIB$hashCode$4()I")) {
                       return 17;                }                break;            case -1184972270:                if (var10000.equals("setName(Ljava/lang/String;)V")) {
                       return 8;                }                break;            case -894172689:                if (var10000.equals("newInstance(Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
                       return 6;                }                break;            case -623122092:                if (var10000.equals("CGLIB$findMethodProxy(Lnet/sf/cglib/core/Signature;)Lnet/sf/cglib/proxy/MethodProxy;")) {
                       return 15;                }                break;            case -508378822:                if (var10000.equals("clone()Ljava/lang/Object;")) {
                       return 3;                }                break;            case -419626537:                if (var10000.equals("setCallbacks([Lnet/sf/cglib/proxy/Callback;)V")) {
                       return 9;                }                break;            case 374345669:                if (var10000.equals("CGLIB$equals$2(Ljava/lang/Object;)Z")) {
                       return 20;                }                break;            case 453440181:                if (var10000.equals("CGLIB$getName$0()Ljava/lang/String;")) {
                       return 19;                }                break;            case 560567118:                if (var10000.equals("setCallback(ILnet/sf/cglib/proxy/Callback;)V")) {
                       return 10;                }                break;            case 811063227:                if (var10000.equals("newInstance([Ljava/lang/Class;[Ljava/lang/Object;[Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
                       return 5;                }                break;            case 973717575:                if (var10000.equals("getCallbacks()[Lnet/sf/cglib/proxy/Callback;")) {
                       return 11;                }                break;            case 1218144844:                if (var10000.equals("getName()Ljava/lang/String;")) {
                       return 4;                }                break;            case 1221173700:                if (var10000.equals("newInstance([Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
                       return 7;                }                break;            case 1230699260:                if (var10000.equals("getCallback(I)Lnet/sf/cglib/proxy/Callback;")) {
                       return 12;                }                break;            case 1341835395:                if (var10000.equals("main([Ljava/lang/String;)V")) {
                       return 23;                }                break;            case 1517819849:                if (var10000.equals("CGLIB$toString$3()Ljava/lang/String;")) {
                       return 18;                }                break;            case 1584330438:                if (var10000.equals("CGLIB$SET_STATIC_CALLBACKS([Lnet/sf/cglib/proxy/Callback;)V")) {
                       return 14;                }                break;            case 1826985398:                if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
                       return 0;                }                break;            case 1913648695:                if (var10000.equals("toString()Ljava/lang/String;")) {
                       return 1;                }                break;            case 1984935277:                if (var10000.equals("hashCode()I")) {
                       return 2;                }                break;            case 2011844968:                if (var10000.equals("CGLIB$clone$5()Ljava/lang/Object;")) {
                       return 22;                }                break;            case 2033562728:                if (var10000.equals("CGLIB$setName$1(Ljava/lang/String;)V")) {
                       return 21;                }        }        return -1;    }    public int getMaxIndex() {
           return 23;    }}

Cglib代理生成的所有类都介绍了,下面介绍cglibProxy.getName();都做了什么

注意这个getName我希望他之前打印before，之后打印after，所以他是一个代理方法，被我增强了

CglibDemo cglibProxy = (CglibDemo) enhancer.create(); 得到的是 CglibDemo$$EnhancerByCGLIB$$1a76a66(类名没有FastClass哦)，我调用的是getName()方法,那么这个代理类一定也有getName()方法:

@SneakyThrows    public final String getName() {
           MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;        if (var10000 == null) {
               CGLIB$BIND_CALLBACKS(this);            var10000 = this.CGLIB$CALLBACK_0;        }        return var10000 != null ? (String)var10000.intercept(this, CGLIB$getName$0$Method, CGLIB$emptyArgs, CGLIB$getName$0$Proxy) : super.getName();    }

他实际调用的是拦截器的intercept方法,拦截器就是:

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

好吧我们把它贴到一起做一个对比

var10000.intercept(this,          CGLIB$getName$0$Method,    CGLIB$emptyArgs,     CGLIB$getName$0$Proxy) @Override public Object intercept(Object obj,    Method method,             Object[] args,       MethodProxy proxy) throws Throwable {
   }

然后到了拦截器的intercept方法，我调用了proxy.invokeSuper(obj, args);

到这里, 就必须说说之前我为什么说一个FastClass是1,另一个FastClass是2, 看invokeSuper源码:

public Object invokeSuper(Object obj, Object[] args) throws Throwable {
           try {
               init();            FastClassInfo fci = fastClassInfo;            return fci.f2.invoke(fci.i2, obj, args);        } catch (InvocationTargetException e) {
               throw e.getTargetException();        }    }

其中, FastClassInfo就包含了两个FastClass, 他的两个属性,f1=CglibDemo$$FastClassByCGLIB$$4320d206和f2=CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752

所以, invokeSuper他用的是FastClass2,也就是f2, (invoke使用的是FastClass1也就是f1), Object参数还是代理对象啊, 当然还有一个属性,fci.i2, 这个i2就是index2的意思,就是方法索引, 这个方法索引什么意思呢, 继续往下看. 现在调用的是FastClass2的invoke,我们看看这个invoke里面写的是啥:

public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
           CglibDemo$$EnhancerByCGLIB$$1a76a66 var10000 = (CglibDemo$$EnhancerByCGLIB$$1a76a66)var2;        int var10001 = var1;        try {
               switch(var10001) {
                   case 0:                    return new Boolean(var10000.equals(var3[0]));                case 1:                    return var10000.toString();                case 2:                    return new Integer(var10000.hashCode());                case 3:                    return var10000.clone();                case 4:                    return var10000.getName();                case 5:                    return var10000.newInstance((Class[])var3[0], (Object[])var3[1], (Callback[])var3[2]);                case 6:                    return var10000.newInstance((Callback)var3[0]);                case 7:                    return var10000.newInstance((Callback[])var3[0]);                case 8:                    var10000.setName((String)var3[0]);                    return null;                case 9:                    var10000.setCallbacks((Callback[])var3[0]);                    return null;                case 10:                    var10000.setCallback(((Number)var3[0]).intValue(), (Callback)var3[1]);                    return null;                case 11:                    return var10000.getCallbacks();                case 12:                    return var10000.getCallback(((Number)var3[0]).intValue());                case 13:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$SET_THREAD_CALLBACKS((Callback[])var3[0]);                    return null;                case 14:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$SET_STATIC_CALLBACKS((Callback[])var3[0]);                    return null;                case 15:                    return CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$findMethodProxy((Signature)var3[0]);                case 16:                    CglibDemo$$EnhancerByCGLIB$$1a76a66.CGLIB$STATICHOOK1();                    return null;                case 17:                    return new Integer(var10000.CGLIB$hashCode$4());                case 18:                    return var10000.CGLIB$toString$3();                case 19:                    return var10000.CGLIB$getName$0();                case 20:                    return new Boolean(var10000.CGLIB$equals$2(var3[0]));                case 21:                    var10000.CGLIB$setName$1((String)var3[0]);                    return null;                case 22:                    return var10000.CGLIB$clone$5();                case 23:                    CglibDemo.main((String[])var3[0]);                    return null;            }        } catch (Throwable var4) {
               throw new InvocationTargetException(var4);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }

这里就是根据方法索引去找方法, 很显然我调用的是getName,那么这个case语句有两个getName:

case 4:       return var10000.getName();case 19:      return var10000.CGLIB$getName$0();

var10000是代理对象啊(切记), 所以这里不会调用var10000.getName() 因为如果调用的是这个,那么就无限循环调用代理的getName方法了, 好,我们看看代理对象CglibDemo$$EnhancerByCGLIB$$1a76a66的CGLIB$getName$0方法:

final String CGLIB$getName$0() {
           return super.getName();    }

前面介绍了,代理对象是CglibDemo的子类,这里的super就是CglibDemo,所以到这里就调用了CglibDemo的getName方法了:

public String getName() {
           System.out.println("get name...");        return name;    }

到这里, 主体流程讲完了,现在讲下有些细节

一个方法在代理对象的构造

private static Method CGLIB$getName$0$Method; private static MethodProxy CGLIB$getName$0$Proxy;  public final String getName() {
      MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;     if (var10000 == null) {
            CGLIB$BIND_CALLBACKS(this);         var10000 = this.CGLIB$CALLBACK_0;     }     return var10000 != null ? (String)var10000.intercept(this, CGLIB$getName$0$Method, CGLIB$emptyArgs, CGLIB$getName$0$Proxy) : super.getName(); }final String CGLIB$getName$0() {
       return super.getName();}

每个方法,都有这么些东西:

  • Method CGLIB$getName$0$Method 反射的原生方法
  • MethodProxy CGLIB$getName$0$Proxy 增强方法,这个方法涉及到FastClass,和方法的索引,方法的索引其实是根据方法的name和参数type的HashCode生成的, 将他的HashCode分配一个int的索引值,比如1,2或者其他数字,比如:
public int getIndex(Signature var1) {
           String var10000 = var1.toString();        switch(var10000.hashCode()) {
               case 453440181:                if (var10000.equals("CGLIB$getName$0()Ljava/lang/String;")) {
                       return 19;                }                break;             case 1218144844:                if (var10000.equals("getName()Ljava/lang/String;")) {
                       return 4;                }                break;

其中Signature就是根据方法名和参数类型调用toString方法生成的, 方法的hashCode和方法的index是早就对应好了的，因为这些FastClass和代理class都是调用asm生成的，生成的时候，这些就已经对应好了

现在讲解一下FastClass1，也就是如果我在拦截器调用proxy.invoke(obj, args); 会发生啥

invoke的源码:

public Object invoke(Object obj, Object[] args) throws Throwable {
           try {
               init();            FastClassInfo fci = fastClassInfo;            return fci.f1.invoke(fci.i1, obj, args);        } catch (InvocationTargetException e) {
               throw e.getTargetException();        } catch (IllegalArgumentException e) {
               if (fastClassInfo.i1 < 0)                throw new IllegalArgumentException("Protected method: " + sig1);            throw e;        }    }

跟invokeSuper的唯一区别就是, invoke使用的是fci.f1也就是FastClass1, 就是CglibDemo$$FastClassByCGLIB$$4320d206

invokeSuper使用的是fci.f2也就是FastClass2,也就是CglibDemo$$EnhancerByCGLIB$$1a76a66$$FastClassByCGLIB$$ea5d0752

那么,FastClass1.invoke发生了啥? ,贴上FastClass1的invoke源码:

public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
           CglibDemo var10000 = (CglibDemo)var2;        int var10001 = var1;        try {
               switch(var10001) {
                   case 0:                    CglibDemo.main((String[])var3[0]);                    return null;                case 1:                    return var10000.getName();                case 2:                    var10000.setName((String)var3[0]);                    return null;                case 3:                    return new Boolean(var10000.equals(var3[0]));                case 4:                    return var10000.toString();                case 5:                    return new Integer(var10000.hashCode());            }        } catch (Throwable var4) {
               throw new InvocationTargetException(var4);        }        throw new IllegalArgumentException("Cannot find matching method/constructor");    }

好吧,调用的是var10000.getName(); 调用的还是代理类的getName,所以又循环调用了,注意注意 CglibDemo var10000 = (CglibDemo)var2; 他不是真的CglibDemo,而是一个代理类, 是CglibDemo$$EnhancerByCGLIB$$1a76a66 extends CglibDemo

好了到这里已经讲解完毕cglib的原理, 以下是问答:

  • 源码是使用hsdb从内存直接dump的,也可以System.setProperty(DebuggingClassWriter.DEBUG_LOCATION_PROPERTY, “c:\classes”);生成. 这里不介绍这个,以后有时间介绍
  • 不可以debug,因为字节码的行号,和反编译的行号对应不上,因为使用的是asm生成的所以行号乱了,不过debug下还是可以看到FastClass的静态字段
  • 他的调用方式区别与jdk动态代理,使用的是方法签名的HashCode去case when找到具体方法,所以不是反射,效率会比反射高一点(经过测试,不是特别明显)
  • 每个方法都会生成一个MethodProxy, 里面fastClass是一样的,但是方法索引是不同的

最后串一遍流程

proxy.getName() —>intercept.invoke(…)—>methodProxy.invokeSuper()—>fastClass.f2.invoke()—>经过case when找到var10000.CGLIB$getName 0 ( ) − − − − > 然 后 又 到 了 p r o x y ， 调 用 C G L I B 0() ----> 然后又到了proxy，调用CGLIB 0()−−−−>然后又到了proxy，调用CGLIBgetName$0----> super.getName() 完毕

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