代理模式 & Java原生动态代理技术 & CGLib动态代理技术

 1 package net.battier.dao.impl;
 2 
 3 import net.battier.dao.BookFacade;
 4 
 5 public class BookFacadeImpl implements BookFacade {
 6 
 7     @Override
 8     public void addBook() {
 9         System.out.println("增加图书方法。。。");
10     }
11 
12 }
13 
14 、BookFacadeProxy.java
15 
16 package net.battier.proxy;
17 
18 import java.lang.reflect.InvocationHandler;
19 import java.lang.reflect.Method;
20 import java.lang.reflect.Proxy;
21 
22 /**
23  * JDK动态代理代理类
24  * 
25  * @author student
26  * 
27  */
28 public class BookFacadeProxy implements InvocationHandler {
29     private Object target;
30     /**
31      * 绑定委托对象并返回一个代理类
32      * @param target
33      * @return
34      */
35     public Object bind(Object target) {
36         this.target = target;
37         //取得代理对象
38         return Proxy.newProxyInstance(target.getClass().getClassLoader(),
39                 target.getClass().getInterfaces(), this);   //要绑定接口(这是一个缺陷，cglib弥补了这一缺陷)
40     }
41 
42     @Override
43     /**
44      * 调用方法
45      */
46     public Object invoke(Object proxy, Method method, Object[] args)
47             throws Throwable {
48         Object result=null;
49         System.out.println("事物开始");
50         //执行方法
51         result=method.invoke(target, args);
52         System.out.println("事物结束");
53         return result;
54     }
55 
56 }

 1 public final class $Proxy0 extends Proxy implements Subject {
 2     private static Method m1;
 3     private static Method m0;
 4     private static Method m3;
 5     private static Method m2;
 6 
 7     static {
 8         try {
 9             m1 = Class.forName("java.lang.Object").getMethod("equals",
10                     new Class[] { Class.forName("java.lang.Object") });
11 
12             m0 = Class.forName("java.lang.Object").getMethod("hashCode",
13                     new Class[0]);
14 
15             m3 = Class.forName("***.RealSubject").getMethod("request",
16                     new Class[0]);
17 
18             m2 = Class.forName("java.lang.Object").getMethod("toString",
19                     new Class[0]);
20 
21         } catch (NoSuchMethodException nosuchmethodexception) {
22             throw new NoSuchMethodError(nosuchmethodexception.getMessage());
23         } catch (ClassNotFoundException classnotfoundexception) {
24             throw new NoClassDefFoundError(classnotfoundexception.getMessage());
25         }
26     } //static
27 
28     public $Proxy0(InvocationHandler invocationhandler) {
29         super(invocationhandler);
30     }
31 
32     @Override
33     public final boolean equals(Object obj) {
34         try {
35             return ((Boolean) super.h.invoke(this, m1, new Object[] { obj })) .booleanValue();
36         } catch (Throwable throwable) {
37             throw new UndeclaredThrowableException(throwable);
38         }
39     }
40 
41     @Override
42     public final int hashCode() {
43         try {
44             return ((Integer) super.h.invoke(this, m0, null)).intValue();
45         } catch (Throwable throwable) {
46             throw new UndeclaredThrowableException(throwable);
47         }
48     }
49 
50     public final void request() {
51         try {
52             super.h.invoke(this, m3, null);
53             return;
54         } catch (Error e) {
55         } catch (Throwable throwable) {
56             throw new UndeclaredThrowableException(throwable);
57         }
58     }
59 
60     @Override
61     public final String toString() {
62         try {
63             return (String) super.h.invoke(this, m2, null);
64         } catch (Throwable throwable) {
65             throw new UndeclaredThrowableException(throwable);
66         }
67     }
68 }

package net.battier.dao;

public interface BookFacade {
    public void addBook();
}

package net.battier.dao.impl;

/**
 * 这个是没有实现接口的实现类
 * 
 * @author student
 * 
 */
public class BookFacadeImpl1 {
    public void addBook() {
        System.out.println("增加图书的普通方法...");
    }
}

 1 package net.battier.proxy;
 2 
 3 import java.lang.reflect.Method;
 4 
 5 import net.sf.cglib.proxy.Enhancer;
 6 import net.sf.cglib.proxy.MethodInterceptor;
 7 import net.sf.cglib.proxy.MethodProxy;
 8 
 9 /**
10  * 使用cglib动态代理
11  * 
12  * @author student
13  * 
14  */
15 public class BookFacadeCglib implements MethodInterceptor {
16     private Object target;
17 
18     /**
19      * 创建代理对象
20      * 
21      * @param target
22      * @return
23      */
24     public Object getInstance(Object target) {
25         this.target = target;
26         Enhancer enhancer = new Enhancer();
27         enhancer.setSuperclass(this.target.getClass());
28         // 回调方法
29         enhancer.setCallback(this);
30         // 创建代理对象
31         return enhancer.create();
32     }
33 
34     @Override
35     // 回调方法
36     public Object intercept(Object obj, Method method, Object[] args,
37             MethodProxy proxy) throws Throwable {
38         System.out.println("事物开始");
39         proxy.invokeSuper(obj, args);
40         System.out.println("事物结束");
41         return null;
42 
43 
44     }
45 
46 }