前面介绍到MethodProxy对象，表示一个方法的代理，比如UserSerivce中的test()方法，在对应的代理类中会有对应的两个方法：

    1. public class UserInterface$$EnhancerByCGLIB$$20ecfdd implements UserInterface, Factory {
    3.     final void CGLIB$test$4() {
    4.         super.test();
    5.     }
    7.     public final void test() {
    8.         MethodInterceptor var10000 = this.CGLIB$CALLBACK_0;
    9.         if (var10000 == null) {
    10.             CGLIB$BIND_CALLBACKS(this);
    11.             var10000 = this.CGLIB$CALLBACK_0;
    12.         }
    14.         if (var10000 != null) {
    15.             var10000.intercept(this, CGLIB$test$4$Method, CGLIB$emptyArgs, CGLIB$test$4$Proxy);
    16.         } else {
    17.             super.test();
    18.         }
    19.     }
    22. }

    而MethodProxy对象代理就是这两个方法，比如：

    1. // 表示执行某个对象的CGLIB$test$0()方法，如果o中没有CGLIB$test$0()方法则会报错
    2. methodProxy.invokeSuper(o, args)
    4. // 表示执行某个对象的test方法
    5. methodProxy.invoke(o, args)

    我们先来看一下MethodProxy对象的创建，创建的入口在代理类中：

    1. CGLIB$test$0$Proxy = MethodProxy.create(var1, var0, "()V", "test", "CGLIB$test$0");

    对应的方法为：

    1. public static MethodProxy create(Class c1, Class c2, String desc, String name1, String name2) {
    2.     // c1是UserService类
    3.     // c2是UserService代理类
    4.     // desc是方法的返回类型 ()V
    5.     // name1是方法名 test
    6.     // name2是代理类中对应的另外一个方法名，CGLIB$test$0
    8.     MethodProxy proxy = new MethodProxy();
    9.     proxy.sig1 = new Signature(name1, desc);  
    10.     proxy.sig2 = new Signature(name2, desc);  
    11.     proxy.createInfo = new CreateInfo(c1, c2); 
    12.     return proxy;
    13. }

    可以发现MethodProxy对象中主要有三个属性：

    1. sig1，表示test方法
    2. sig2，表示CGLIB$test$0方法
    3. createInfo，表示UserService类和UserService代理类

    我们再来看MethodProxy的invoke()和invokeSuper()方法：

    1. public Object invoke(Object obj, Object[] args) throws Throwable {
    2.         try {
    4.             init();
    5.             FastClassInfo fci = fastClassInfo;
    7.             return fci.f1.invoke(fci.i1, obj, args);
    8.         } catch (InvocationTargetException e) {
    9.             throw e.getTargetException();
    10.         } catch (IllegalArgumentException e) {
    11.             if (fastClassInfo.i1 < 0)
    12.                 throw new IllegalArgumentException("Protected method: " + sig1);
    13.             throw e;
    14.         }
    15. }
    17. public Object invokeSuper(Object obj, Object[] args) throws Throwable {
    18.         try {
    20.             init();
    21.             FastClassInfo fci = fastClassInfo;
    23.             return fci.f2.invoke(fci.i2, obj, args);
    24.         } catch (InvocationTargetException e) {
    25.             throw e.getTargetException();
    26.         }
    27. }

    我们可以发现，这两个方法差不多，首先都需要用到一个FastClassInfo对象，这个对象是在init()方法构造的。

    1. private void init() {
    3.         if (fastClassInfo == null) {
    4.             synchronized (initLock) {
    5.                 if (fastClassInfo == null) {
    7.                     CreateInfo ci = createInfo;
    9.                     FastClassInfo fci = new FastClassInfo();
    10.                     fci.f1 = helper(ci, ci.c1); 
    11.                     fci.f2 = helper(ci, ci.c2);
    13.                     fci.i1 = fci.f1.getIndex(sig1); 
    14.                     fci.i2 = fci.f2.getIndex(sig2); 
    15.                     fastClassInfo = fci;
    16.                     createInfo = null;
    17.                 }
    18.             }
    19.         }
    21. }

    FastClassInfo对象中主要有四个属性：

    1. f1，UserService类对应的一个FastClass代理对象
    2. f2，UserService代理类对应的一个FastClass代理对象
    3. i1，test方法在UserService类对应的一个FastClass代理对象中的下标
    4. i2，CGLIB$test$0方法在UserService代理对对应的一个FastClass代理对象

    我们可以看到这里应该将会产生两个FastClass代理类

    以下是UserService所对应的FastClass代理类，继承了FastClass

    1. //
    2. // Source code recreated from a .class file by IntelliJ IDEA
    3. // (powered by FernFlower decompiler)
    4. //
    6. package com.zhouyu;
    8. import java.lang.reflect.InvocationTargetException;
    9. import net.sf.cglib.core.Signature;
    10. import net.sf.cglib.reflect.FastClass;
    12. public class UserService$$FastClassByCGLIB$$4fef7899 extends FastClass {
    13.     public UserService$$FastClassByCGLIB$$4fef7899(Class var1) {
    14.         super(var1);
    15.     }
    17.     public int getIndex(Signature var1) {
    18.         String var10000 = var1.toString();
    19.         switch(var10000.hashCode()) {
    20.         case -1422510685:
    21.             if (var10000.equals("test()V")) {
    22.                 return 0;
    23.             }
    24.             break;
    25.         case 1826985398:
    26.             if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
    27.                 return 1;
    28.             }
    29.             break;
    30.         case 1913648695:
    31.             if (var10000.equals("toString()Ljava/lang/String;")) {
    32.                 return 2;
    33.             }
    34.             break;
    35.         case 1984935277:
    36.             if (var10000.equals("hashCode()I")) {
    37.                 return 3;
    38.             }
    39.         }
    41.         return -1;
    42.     }
    44.     public int getIndex(String var1, Class[] var2) {
    45.         switch(var1.hashCode()) {
    46.         case -1776922004:
    47.             if (var1.equals("toString")) {
    48.                 switch(var2.length) {
    49.                 case 0:
    50.                     return 2;
    51.                 }
    52.             }
    53.             break;
    54.         case -1295482945:
    55.             if (var1.equals("equals")) {
    56.                 switch(var2.length) {
    57.                 case 1:
    58.                     if (var2[0].getName().equals("java.lang.Object")) {
    59.                         return 1;
    60.                     }
    61.                 }
    62.             }
    63.             break;
    64.         case 3556498:
    65.             if (var1.equals("test")) {
    66.                 switch(var2.length) {
    67.                 case 0:
    68.                     return 0;
    69.                 }
    70.             }
    71.             break;
    72.         case 147696667:
    73.             if (var1.equals("hashCode")) {
    74.                 switch(var2.length) {
    75.                 case 0:
    76.                     return 3;
    77.                 }
    78.             }
    79.         }
    81.         return -1;
    82.     }
    84.     public int getIndex(Class[] var1) {
    85.         switch(var1.length) {
    86.         case 0:
    87.             return 0;
    88.         default:
    89.             return -1;
    90.         }
    91.     }
    93.     public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
    94.         UserService var10000 = (UserService)var2;
    95.         int var10001 = var1;
    97.         try {
    98.             switch(var10001) {
    99.             case 0:
    100.                 var10000.test();
    101.                 return null;
    102.             case 1:
    103.                 return new Boolean(var10000.equals(var3[0]));
    104.             case 2:
    105.                 return var10000.toString();
    106.             case 3:
    107.                 return new Integer(var10000.hashCode());
    108.             }
    109.         } catch (Throwable var4) {
    110.             throw new InvocationTargetException(var4);
    111.         }
    113.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    114.     }
    116.     public Object newInstance(int var1, Object[] var2) throws InvocationTargetException {
    117.         UserService var10000 = new UserService;
    118.         UserService var10001 = var10000;
    119.         int var10002 = var1;
    121.         try {
    122.             switch(var10002) {
    123.             case 0:
    124.                 var10001.<init>();
    125.                 return var10000;
    126.             }
    127.         } catch (Throwable var3) {
    128.             throw new InvocationTargetException(var3);
    129.         }
    131.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    132.     }
    134.     public int getMaxIndex() {
    135.         return 3;
    136.     }
    137. }

    以下是UserService代理类所对应的FastClass代理类，继承了FastClass

    1. //
    2. // Source code recreated from a .class file by IntelliJ IDEA
    3. // (powered by FernFlower decompiler)
    4. //
    6. package com.zhouyu;
    8. import com.zhouyu.UserService..EnhancerByCGLIB..4d890297;
    9. import java.lang.reflect.InvocationTargetException;
    10. import net.sf.cglib.core.Signature;
    11. import net.sf.cglib.proxy.Callback;
    12. import net.sf.cglib.reflect.FastClass;
    14. public class UserService$$EnhancerByCGLIB$$4d890297$$FastClassByCGLIB$$6ea3bb5e extends FastClass {
    15.     public UserService$$EnhancerByCGLIB$$4d890297$$FastClassByCGLIB$$6ea3bb5e(Class var1) {
    16.         super(var1);
    17.     }
    19.     public int getIndex(Signature var1) {
    20.         String var10000 = var1.toString();
    21.         switch(var10000.hashCode()) {
    22.         case -2055565910:
    23.             if (var10000.equals("CGLIB$SET_THREAD_CALLBACKS([Lnet/sf/cglib/proxy/Callback;)V")) {
    24.                 return 4;
    25.             }
    26.             break;
    27.         case -1882565338:
    28.             if (var10000.equals("CGLIB$equals$1(Ljava/lang/Object;)Z")) {
    29.                 return 9;
    30.             }
    31.             break;
    32.         case -1659809612:
    33.             if (var10000.equals("CGLIB$test$0()V")) {
    34.                 return 8;
    35.             }
    36.             break;
    37.         case -1457535688:
    38.             if (var10000.equals("CGLIB$STATICHOOK1()V")) {
    39.                 return 7;
    40.             }
    41.             break;
    42.         case -1422510685:
    43.             if (var10000.equals("test()V")) {
    44.                 return 20;
    45.             }
    46.             break;
    47.         case -1411842725:
    48.             if (var10000.equals("CGLIB$hashCode$3()I")) {
    49.                 return 11;
    50.             }
    51.             break;
    52.         case -894172689:
    53.             if (var10000.equals("newInstance(Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
    54.                 return 18;
    55.             }
    56.             break;
    57.         case -623122092:
    58.             if (var10000.equals("CGLIB$findMethodProxy(Lnet/sf/cglib/core/Signature;)Lnet/sf/cglib/proxy/MethodProxy;")) {
    59.                 return 6;
    60.             }
    61.             break;
    62.         case -508378822:
    63.             if (var10000.equals("clone()Ljava/lang/Object;")) {
    64.                 return 16;
    65.             }
    66.             break;
    67.         case -419626537:
    68.             if (var10000.equals("setCallbacks([Lnet/sf/cglib/proxy/Callback;)V")) {
    69.                 return 1;
    70.             }
    71.             break;
    72.         case 560567118:
    73.             if (var10000.equals("setCallback(ILnet/sf/cglib/proxy/Callback;)V")) {
    74.                 return 0;
    75.             }
    76.             break;
    77.         case 811063227:
    78.             if (var10000.equals("newInstance([Ljava/lang/Class;[Ljava/lang/Object;[Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
    79.                 return 19;
    80.             }
    81.             break;
    82.         case 973717575:
    83.             if (var10000.equals("getCallbacks()[Lnet/sf/cglib/proxy/Callback;")) {
    84.                 return 2;
    85.             }
    86.             break;
    87.         case 1221173700:
    88.             if (var10000.equals("newInstance([Lnet/sf/cglib/proxy/Callback;)Ljava/lang/Object;")) {
    89.                 return 17;
    90.             }
    91.             break;
    92.         case 1230699260:
    93.             if (var10000.equals("getCallback(I)Lnet/sf/cglib/proxy/Callback;")) {
    94.                 return 3;
    95.             }
    96.             break;
    97.         case 1306468936:
    98.             if (var10000.equals("CGLIB$toString$2()Ljava/lang/String;")) {
    99.                 return 10;
    100.             }
    101.             break;
    102.         case 1584330438:
    103.             if (var10000.equals("CGLIB$SET_STATIC_CALLBACKS([Lnet/sf/cglib/proxy/Callback;)V")) {
    104.                 return 5;
    105.             }
    106.             break;
    107.         case 1800494055:
    108.             if (var10000.equals("CGLIB$clone$4()Ljava/lang/Object;")) {
    109.                 return 12;
    110.             }
    111.             break;
    112.         case 1826985398:
    113.             if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
    114.                 return 13;
    115.             }
    116.             break;
    117.         case 1913648695:
    118.             if (var10000.equals("toString()Ljava/lang/String;")) {
    119.                 return 14;
    120.             }
    121.             break;
    122.         case 1984935277:
    123.             if (var10000.equals("hashCode()I")) {
    124.                 return 15;
    125.             }
    126.         }
    128.         return -1;
    129.     }
    131.     public int getIndex(String var1, Class[] var2) {
    132.         switch(var1.hashCode()) {
    133.         case -1776922004:
    134.             if (var1.equals("toString")) {
    135.                 switch(var2.length) {
    136.                 case 0:
    137.                     return 14;
    138.                 }
    139.             }
    140.             break;
    141.         case -1295482945:
    142.             if (var1.equals("equals")) {
    143.                 switch(var2.length) {
    144.                 case 1:
    145.                     if (var2[0].getName().equals("java.lang.Object")) {
    146.                         return 13;
    147.                     }
    148.                 }
    149.             }
    150.             break;
    151.         case -1053468136:
    152.             if (var1.equals("getCallbacks")) {
    153.                 switch(var2.length) {
    154.                 case 0:
    155.                     return 2;
    156.                 }
    157.             }
    158.             break;
    159.         case -124978609:
    160.             if (var1.equals("CGLIB$equals$1")) {
    161.                 switch(var2.length) {
    162.                 case 1:
    163.                     if (var2[0].getName().equals("java.lang.Object")) {
    164.                         return 9;
    165.                     }
    166.                 }
    167.             }
    168.             break;
    169.         case -60403779:
    170.             if (var1.equals("CGLIB$SET_STATIC_CALLBACKS")) {
    171.                 switch(var2.length) {
    172.                 case 1:
    173.                     if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
    174.                         return 5;
    175.                     }
    176.                 }
    177.             }
    178.             break;
    179.         case -29025555:
    180.             if (var1.equals("CGLIB$hashCode$3")) {
    181.                 switch(var2.length) {
    182.                 case 0:
    183.                     return 11;
    184.                 }
    185.             }
    186.             break;
    187.         case 3556498:
    188.             if (var1.equals("test")) {
    189.                 switch(var2.length) {
    190.                 case 0:
    191.                     return 20;
    192.                 }
    193.             }
    194.             break;
    195.         case 85179481:
    196.             if (var1.equals("CGLIB$SET_THREAD_CALLBACKS")) {
    197.                 switch(var2.length) {
    198.                 case 1:
    199.                     if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
    200.                         return 4;
    201.                     }
    202.                 }
    203.             }
    204.             break;
    205.         case 94756189:
    206.             if (var1.equals("clone")) {
    207.                 switch(var2.length) {
    208.                 case 0:
    209.                     return 16;
    210.                 }
    211.             }
    212.             break;
    213.         case 147696667:
    214.             if (var1.equals("hashCode")) {
    215.                 switch(var2.length) {
    216.                 case 0:
    217.                     return 15;
    218.                 }
    219.             }
    220.             break;
    221.         case 161998109:
    222.             if (var1.equals("CGLIB$STATICHOOK1")) {
    223.                 switch(var2.length) {
    224.                 case 0:
    225.                     return 7;
    226.                 }
    227.             }
    228.             break;
    229.         case 495524492:
    230.             if (var1.equals("setCallbacks")) {
    231.                 switch(var2.length) {
    232.                 case 1:
    233.                     if (var2[0].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
    234.                         return 1;
    235.                     }
    236.                 }
    237.             }
    238.             break;
    239.         case 543320865:
    240.             if (var1.equals("CGLIB$test$0")) {
    241.                 switch(var2.length) {
    242.                 case 0:
    243.                     return 8;
    244.                 }
    245.             }
    246.             break;
    247.         case 1154623345:
    248.             if (var1.equals("CGLIB$findMethodProxy")) {
    249.                 switch(var2.length) {
    250.                 case 1:
    251.                     if (var2[0].getName().equals("net.sf.cglib.core.Signature")) {
    252.                         return 6;
    253.                     }
    254.                 }
    255.             }
    256.             break;
    257.         case 1543336189:
    258.             if (var1.equals("CGLIB$toString$2")) {
    259.                 switch(var2.length) {
    260.                 case 0:
    261.                     return 10;
    262.                 }
    263.             }
    264.             break;
    265.         case 1811874389:
    266.             if (var1.equals("newInstance")) {
    267.                 switch(var2.length) {
    268.                 case 1:
    269.                     String var10001 = var2[0].getName();
    270.                     switch(var10001.hashCode()) {
    271.                     case -845341380:
    272.                         if (var10001.equals("net.sf.cglib.proxy.Callback")) {
    273.                             return 18;
    274.                         }
    275.                         break;
    276.                     case 1730110032:
    277.                         if (var10001.equals("[Lnet.sf.cglib.proxy.Callback;")) {
    278.                             return 17;
    279.                         }
    280.                     }
    281.                 case 2:
    282.                 default:
    283.                     break;
    284.                 case 3:
    285.                     if (var2[0].getName().equals("[Ljava.lang.Class;") && var2[1].getName().equals("[Ljava.lang.Object;") && var2[2].getName().equals("[Lnet.sf.cglib.proxy.Callback;")) {
    286.                         return 19;
    287.                     }
    288.                 }
    289.             }
    290.             break;
    291.         case 1817099975:
    292.             if (var1.equals("setCallback")) {
    293.                 switch(var2.length) {
    294.                 case 2:
    295.                     if (var2[0].getName().equals("int") && var2[1].getName().equals("net.sf.cglib.proxy.Callback")) {
    296.                         return 0;
    297.                     }
    298.                 }
    299.             }
    300.             break;
    301.         case 1905679803:
    302.             if (var1.equals("getCallback")) {
    303.                 switch(var2.length) {
    304.                 case 1:
    305.                     if (var2[0].getName().equals("int")) {
    306.                         return 3;
    307.                     }
    308.                 }
    309.             }
    310.             break;
    311.         case 1951977610:
    312.             if (var1.equals("CGLIB$clone$4")) {
    313.                 switch(var2.length) {
    314.                 case 0:
    315.                     return 12;
    316.                 }
    317.             }
    318.         }
    320.         return -1;
    321.     }
    323.     public int getIndex(Class[] var1) {
    324.         switch(var1.length) {
    325.         case 0:
    326.             return 0;
    327.         default:
    328.             return -1;
    329.         }
    330.     }
    332.     public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
    333.         4d890297 var10000 = (4d890297)var2;
    334.         int var10001 = var1;
    336.         try {
    337.             switch(var10001) {
    338.             case 0:
    339.                 var10000.setCallback(((Number)var3[0]).intValue(), (Callback)var3[1]);
    340.                 return null;
    341.             case 1:
    342.                 var10000.setCallbacks((Callback[])var3[0]);
    343.                 return null;
    344.             case 2:
    345.                 return var10000.getCallbacks();
    346.             case 3:
    347.                 return var10000.getCallback(((Number)var3[0]).intValue());
    348.             case 4:
    349.                 4d890297.CGLIB$SET_THREAD_CALLBACKS((Callback[])var3[0]);
    350.                 return null;
    351.             case 5:
    352.                 4d890297.CGLIB$SET_STATIC_CALLBACKS((Callback[])var3[0]);
    353.                 return null;
    354.             case 6:
    355.                 return 4d890297.CGLIB$findMethodProxy((Signature)var3[0]);
    356.             case 7:
    357.                 4d890297.CGLIB$STATICHOOK1();
    358.                 return null;
    359.             case 8:
    360.                 var10000.CGLIB$test$0();
    361.                 return null;
    362.             case 9:
    363.                 return new Boolean(var10000.CGLIB$equals$1(var3[0]));
    364.             case 10:
    365.                 return var10000.CGLIB$toString$2();
    366.             case 11:
    367.                 return new Integer(var10000.CGLIB$hashCode$3());
    368.             case 12:
    369.                 return var10000.CGLIB$clone$4();
    370.             case 13:
    371.                 return new Boolean(var10000.equals(var3[0]));
    372.             case 14:
    373.                 return var10000.toString();
    374.             case 15:
    375.                 return new Integer(var10000.hashCode());
    376.             case 16:
    377.                 return var10000.clone();
    378.             case 17:
    379.                 return var10000.newInstance((Callback[])var3[0]);
    380.             case 18:
    381.                 return var10000.newInstance((Callback)var3[0]);
    382.             case 19:
    383.                 return var10000.newInstance((Class[])var3[0], (Object[])var3[1], (Callback[])var3[2]);
    384.             case 20:
    385.                 var10000.test();
    386.                 return null;
    387.             }
    388.         } catch (Throwable var4) {
    389.             throw new InvocationTargetException(var4);
    390.         }
    392.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    393.     }
    395.     public Object newInstance(int var1, Object[] var2) throws InvocationTargetException {
    396.         4d890297 var10000 = new 4d890297;
    397.         4d890297 var10001 = var10000;
    398.         int var10002 = var1;
    400.         try {
    401.             switch(var10002) {
    402.             case 0:
    403.                 var10001.<init>();
    404.                 return var10000;
    405.             }
    406.         } catch (Throwable var3) {
    407.             throw new InvocationTargetException(var3);
    408.         }
    410.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    411.     }
    413.     public int getMaxIndex() {
    414.         return 20;
    415.     }
    416. }

    其实这两个类类似，都是针对某一个类的FastClass代理类，所以我们好好看一下UserService所对应的FastClass，该类主要有：

    1. 一个构造方法
    2. public int getIndex(Signature var1)
    3. public int getIndex(String var1, Class[] var2)
    4. public int getIndex(Class[] var1)
    5. public Object invoke(int var1, Object var2, Object[] var3)
    6. public Object newInstance(int var1, Object[] var2)
    7. public int getMaxIndex()

    顾名思义，FastClass的作用是提高方法的执行速度，按照正常的实现，当我们调用MethodProxy对象的invoke()或invokeSuper()方法时，首先应该要做到的就是找到对应的Method对象，比如：

    1. 执行invoke()，要找到test方法对应的Method对象
    2. 执行invokeSuper()，要找到CGLIB$test$0()方法对应的Method对象

    然后利用反射来执行Method。

    那么FastClass的机制就是预先把UserService类或UserService代理类中的所有方法做一个索引，比如：

    1. public int getIndex(Signature var1) {
    2.         String var10000 = var1.toString();
    3.         switch(var10000.hashCode()) {
    4.         case -1422510685:
    5.             if (var10000.equals("test()V")) {
    6.                 return 0;
    7.             }
    8.             break;
    9.         case 1826985398:
    10.             if (var10000.equals("equals(Ljava/lang/Object;)Z")) {
    11.                 return 1;
    12.             }
    13.             break;
    14.         case 1913648695:
    15.             if (var10000.equals("toString()Ljava/lang/String;")) {
    16.                 return 2;
    17.             }
    18.             break;
    19.         case 1984935277:
    20.             if (var10000.equals("hashCode()I")) {
    21.                 return 3;
    22.             }
    23.         }
    25.         return -1;
    26. }

    一旦调了这个方法，就会得到当前要执行的方法所对应的index，比如test()对应的index为0
    我们再来看init()方法：

    1. private void init() {
    3.         if (fastClassInfo == null) {
    4.             synchronized (initLock) {
    5.                 if (fastClassInfo == null) {
    7.                     CreateInfo ci = createInfo;
    9.                     FastClassInfo fci = new FastClassInfo();
    10.                     fci.f1 = helper(ci, ci.c1); 
    11.                     fci.f2 = helper(ci, ci.c2);
    13.                     fci.i1 = fci.f1.getIndex(sig1); 
    14.                     fci.i2 = fci.f2.getIndex(sig2); 
    15.                     fastClassInfo = fci;
    16.                     createInfo = null;
    17.                 }
    18.             }
    19.         }
    21. }

    两个helper()方法就是分别去生成UserService类和UserService代理类所对应的FastClass代理类。
    接下来的两个getIndex()，就是分别去：

    1. 去UserService类对应的FastClass代理类中找到test()方法的下标i1
    2. 去UserService代理类对应的FastClass代理类中找到CGLIB$test$0()方法的下标i2

    然后把两个下标都记录在fastClassInfo中。

    紧接着就会去执行：

    1. invoke：fci.f1.invoke(fci.i1, obj, args)，执行UserService类对应的FastClass代理类的invoke方法
    2. invokeSuper：fci.f2.invoke(fci.i2, obj, args)，执行UserService代理类对应的FastClass代理类的invoke方法

    比如UserService类对应的FastClass代理类的invoke方法的代码为：

    1. public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
    2.         UserService var10000 = (UserService)var2;
    3.         int var10001 = var1;
    5.         try {
    6.             switch(var10001) {
    7.             case 0:
    8.                 var10000.test();
    9.                 return null;
    10.             case 1:
    11.                 return new Boolean(var10000.equals(var3[0]));
    12.             case 2:
    13.                 return var10000.toString();
    14.             case 3:
    15.                 return new Integer(var10000.hashCode());
    16.             }
    17.         } catch (Throwable var4) {
    18.             throw new InvocationTargetException(var4);
    19.         }
    21.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    22. }

    我们可以发现代码还是比较简单的，比如如果传入的下标是0，那么就会执行var2的test();

    对于UserService代理类对应的FastClass代理类也类似：

    1. public Object invoke(int var1, Object var2, Object[] var3) throws InvocationTargetException {
    2.         4d890297 var10000 = (4d890297)var2;
    3.         int var10001 = var1;
    5.         try {
    6.             switch(var10001) {
    7.             case 0:
    8.                 var10000.setCallback(((Number)var3[0]).intValue(), (Callback)var3[1]);
    9.                 return null;
    10.             case 1:
    11.                 var10000.setCallbacks((Callback[])var3[0]);
    12.                 return null;
    13.             case 2:
    14.                 return var10000.getCallbacks();
    15.             case 3:
    16.                 return var10000.getCallback(((Number)var3[0]).intValue());
    17.             case 4:
    18.                 4d890297.CGLIB$SET_THREAD_CALLBACKS((Callback[])var3[0]);
    19.                 return null;
    20.             case 5:
    21.                 4d890297.CGLIB$SET_STATIC_CALLBACKS((Callback[])var3[0]);
    22.                 return null;
    23.             case 6:
    24.                 return 4d890297.CGLIB$findMethodProxy((Signature)var3[0]);
    25.             case 7:
    26.                 4d890297.CGLIB$STATICHOOK1();
    27.                 return null;
    28.             case 8:
    29.                 var10000.CGLIB$test$0();
    30.                 return null;
    31.             case 9:
    32.                 return new Boolean(var10000.CGLIB$equals$1(var3[0]));
    33.             case 10:
    34.                 return var10000.CGLIB$toString$2();
    35.             case 11:
    36.                 return new Integer(var10000.CGLIB$hashCode$3());
    37.             case 12:
    38.                 return var10000.CGLIB$clone$4();
    39.             case 13:
    40.                 return new Boolean(var10000.equals(var3[0]));
    41.             case 14:
    42.                 return var10000.toString();
    43.             case 15:
    44.                 return new Integer(var10000.hashCode());
    45.             case 16:
    46.                 return var10000.clone();
    47.             case 17:
    48.                 return var10000.newInstance((Callback[])var3[0]);
    49.             case 18:
    50.                 return var10000.newInstance((Callback)var3[0]);
    51.             case 19:
    52.                 return var10000.newInstance((Class[])var3[0], (Object[])var3[1], (Callback[])var3[2]);
    53.             case 20:
    54.                 var10000.test();
    55.                 return null;
    56.             }
    57.         } catch (Throwable var4) {
    58.             throw new InvocationTargetException(var4);
    59.         }
    61.         throw new IllegalArgumentException("Cannot find matching method/constructor");
    62.     }

    比如下标为8，就会执行var10000.CGLIB$test$0();
    比如下标为20，就会执行var10000.test();
    而var10000，是所传入对象强制转化为4d890297类的对象，4d890297其实就是UserService的代理类。

    所以我们可以发现，当执行invokeSuper()这个方法时，不能传入UserService对象，只能传入UserService的代理对象，不然就不能转换成为UserService代理类类型。

    所以FastClass，快的地方就是预先把方法信息都生成好了，在真正调用的时候，不用再去找Method对象，而是直接就执行方法了。