cglib是個(gè)好東東,說牛刀,是因?yàn)樗軓?qiáng)大,用途很廣。小試,是因?yàn)閮H僅用它做了個(gè)類似hello world的小程序。
cglib是Spring、Hibernate依賴的核心包,但是cglib還算不上最底層的,因?yàn)樗窃赼sm包之上做了封裝,以增強(qiáng)易用性。據(jù)了解,Hibernate3.2已經(jīng)不再依賴cglib了,而直接依賴asm。這些都不影響cglib的強(qiáng)大功能。
很希望將spring、JDK、cglib的動(dòng)態(tài)代理三者放到一起做個(gè)比較(實(shí)際上,spring、jdk的代理已經(jīng)比較過了),也許是地震原因,心情一直沒有平靜下來,無心去寫。下面就先給個(gè)地震前例子看看,因?yàn)楹芎唵危跃筒患?xì)說了,有空了再做深入研究。
其實(shí)所有代理道理都是一樣,就是通過代理對象去調(diào)用目標(biāo)對象,并且在代理對象中做點(diǎn)“手腳”--加入一些其他操作。
下面看例子:
目標(biāo)對象
/**
* Created by IntelliJ IDEA.<br>
* <b>User</b>: leizhimin<br>
* <b>Date</b>: 2008-5-14 0:38:35<br>
* <b>Note</b>: Please add comment here!
*/
public class Target {
public String execute() {
String message = "----------test()----------";
System.out.println(message);
return message;
}
}
攔截器
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
/**
* Created by IntelliJ IDEA.<br>
* <b>User</b>: leizhimin<br>
* <b>Date</b>: 2008-5-14 0:39:08<br>
* <b>Note</b>: Please add comment here!
*/
public class MyMethodInterceptor implements MethodInterceptor {
public Object intercept(Object object, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
System.out.println(">>>MethodInterceptor start...");
Object result = methodProxy.invokeSuper(object,args);
System.out.println(">>>MethodInterceptor ending...");
return "hahahh";
}
}
import net.sf.cglib.proxy.Enhancer;
/**
* Created by IntelliJ IDEA.<br>
* <b>User</b>: leizhimin<br>
* <b>Date</b>: 2008-5-14 0:41:01<br>
* <b>Note</b>: Please add comment here!
*/
public class TestCglibProxy {
public static void main(String rags[]){
Target target = new Target();
TestCglibProxy test = new TestCglibProxy();
Target proxyTarget = (Target)test.createProxy(Target.class);
String res=proxyTarget.execute();
System.out.println(res);
}
public Object createProxy(Class targetClass){
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(targetClass);
enhancer.setCallback(new MyMethodInterceptor());
return enhancer.create();
}
}
運(yùn)行結(jié)果:
C:\classes>java -cp .;C:\classes\cglib-nodep-2.1_3.jar TestCglibProxy
>>>MethodInterceptor start...
----------test()----------
>>>MethodInterceptor ending...
hahahh
C:\classes>