今天稍微看了下JDK與CGLib動態(tài)代理，對兩者的區(qū)別有所了解。
但是同樣是生成字節(jié)碼，在哪里會有所不同，粗略的思考了一下，記錄如下(暫時記錄，以后有時間再細細研究)

JDK動態(tài)代理

生成的字節(jié)碼示例如下：

//這里很清楚了,代理類繼承了Proxy類,并且實現(xiàn)了Proxy.newProxyInstance這個方法中傳入的接口    
public final class $Proxy0 extends Proxy implements ITest {
    private static Method m1;
    private static Method m2;
    private static Method m3;
    private static Method m0;

    public $Proxy0(InvocationHandler var1) throws  {
        super(var1);
    }

    public final boolean equals(Object var1) throws  {
        try {
            return ((Boolean)super.h.invoke(this, m1, new Object[]{var1})).booleanValue();
        } catch (RuntimeException | Error var3) {
            throw var3;
        } catch (Throwable var4) {
            throw new UndeclaredThrowableException(var4);
        }
    }

    public final String toString() throws  {
        try {
            return (String)super.h.invoke(this, m2, (Object[])null);
        } catch (RuntimeException | Error var2) {
            throw var2;
        } catch (Throwable var3) {
            throw new UndeclaredThrowableException(var3);
        }
    }

    public final void test(String var1) throws  {
        try {
            super.h.invoke(this, m3, new Object[]{var1});
        } catch (RuntimeException | Error var3) {
            throw var3;
        } catch (Throwable var4) {
            throw new UndeclaredThrowableException(var4);
        }
    }

    public final int hashCode() throws  {
        try {
            return ((Integer)super.h.invoke(this, m0, (Object[])null)).intValue();
        } catch (RuntimeException | Error var2) {
            throw var2;
        } catch (Throwable var3) {
            throw new UndeclaredThrowableException(var3);
        }
    }

    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("ITest").getMethod("test", new Class[]{Class.forName("java.lang.String")});
            m0 = Class.forName("java.lang.Object").getMethod("hashCode", new Class[0]);
        } catch (NoSuchMethodException var2) {
            throw new NoSuchMethodError(var2.getMessage());
        } catch (ClassNotFoundException var3) {
            throw new NoClassDefFoundError(var3.getMessage());
        }
    }
}

利用java反射調(diào)用目標類方法：super.h.invoke(this, m3, new Object[]{var1});

Cglib動態(tài)代理

生成的字節(jié)碼文件會有多個文件：

1528041767270.png

public class Test$$EnhancerByCGLIB$$4e16a0e7 extends Test implements net.sf.cglib.proxy.Factory {
    private boolean CGLIB$BOUND;
    private static final java.lang.ThreadLocal CGLIB$THREAD_CALLBACKS;
    private static final net.sf.cglib.proxy.Callback[] CGLIB$STATIC_CALLBACKS;
    private net.sf.cglib.proxy.MethodInterceptor CGLIB$CALLBACK_0;
    private static final java.lang.reflect.Method CGLIB$test$0$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$test$0$Proxy;
    private static final java.lang.Object[] CGLIB$emptyArgs;
    private static final java.lang.reflect.Method CGLIB$finalize$1$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$finalize$1$Proxy;
    private static final java.lang.reflect.Method CGLIB$equals$2$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$equals$2$Proxy;
    private static final java.lang.reflect.Method CGLIB$toString$3$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$toString$3$Proxy;
    private static final java.lang.reflect.Method CGLIB$hashCode$4$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$hashCode$4$Proxy;
    private static final java.lang.reflect.Method CGLIB$clone$5$Method;
    private static final net.sf.cglib.proxy.MethodProxy CGLIB$clone$5$Proxy;

    static void CGLIB$STATICHOOK1() { /* compiled code */ }

    final void CGLIB$test$0(java.lang.String s) { /* compiled code */ }

    public final void test(java.lang.String s) { /* compiled code */ }

    final void CGLIB$finalize$1() throws java.lang.Throwable { /* compiled code */ }

    protected final void finalize() throws java.lang.Throwable { /* compiled code */ }

    final boolean CGLIB$equals$2(java.lang.Object o) { /* compiled code */ }

    public final boolean equals(java.lang.Object o) { /* compiled code */ }
    ...

方法中沒有具體的代碼，看來得借助其他工具查看class文件(待續(xù))
參看 cglib原理分析
Jdk動態(tài)代理的攔截對象是通過反射的機制來調(diào)用被攔截方法的，反射的效率比較低，所以cglib采用了FastClass的機制來實現(xiàn)對被攔截方法的調(diào)用。FastClass機制就是對一個類的方法建立索引，通過索引來直接調(diào)用相應(yīng)的方法，