Java uses dynamic proxies to implement an AOP (logging) Instance code _java

Here is a simple example of an AOP implementation:

First, define some business methods:

Copy Code code as follows:

/**
* Created with IntelliJ idea.
* Author:wangjie email:tiantian.china.2@gmail.com
* date:13-9-23
* Time: 3:49
*/
Public interface Bussinessservice {
public string Login (string username, string password);
Public String find ();
}

public class Bussinessserviceimpl implements Bussinessservice {
Private Logger Logger = Logger.getlogger (This.getclass (). Getsimplename ());

@Override
public string Login (string username, string password) {
Return "Login Success";
}

@Override
Public String Find () {
Return "Find success";
}

}

Copy Code code as follows:

/**
* Created with IntelliJ idea.
* Author:wangjie email:tiantian.china.2@gmail.com
* date:13-9-24
* Time: 10:27
*/
Public interface Workservice {
Public String work ();
Public String sleep ();
}

public class Workserviceimpl implements workservice{
@Override
Public String work () {
Return "work success";
}

@Override
Public String sleep () {
Return to "sleep success";
}
}

Implement Invocationhandler interface, use map to store different Invocationhandler objects, avoid generating too much.

Copy Code code as follows:

Package Com.wangjie.aoptest2.invohandler;

Import Java.lang.reflect.InvocationHandler;
Import Java.lang.reflect.Method;
Import Java.lang.reflect.Proxy;
Import Java.util.Arrays;
Import Java.util.HashMap;
Import Java.util.logging.Logger;

/**
* Created with IntelliJ idea.
* Author:wangjie email:tiantian.china.2@gmail.com
* date:13-9-23
* Time: 3:47
*/
public class Loginvohandler implements invocationhandler{
Private Logger Logger = Logger.getlogger (This.getclass (). Getsimplename ());

Private Object target; Agent Target
Private Object proxy; Proxy Object

private static Hashmap<class<?>, loginvohandler> invohandlers = new Hashmap<class<?> Loginvohandler> ();

Private Loginvohandler () {
}

/**
* Generate dynamic proxy object proxy via class
* @param clazz
* @return
*/
Public synchronized static<t> T getproxyinstance (class<t> clazz) {
Loginvohandler Invohandler = Invohandlers.get (clazz);

if (null = = Invohandler) {


Invohandler = new Loginvohandler ();


try {


T tar = clazz.newinstance ();


Invohandler.settarget (TAR);


Invohandler.setproxy (Proxy.newproxyinstance (Tar.getclass (). getClassLoader (),


Tar.getclass (). Getinterfaces (), Invohandler));


catch (Exception e) {


E.printstacktrace ();


}


Invohandlers.put (Clazz, Invohandler);

}

Return (T) invohandler.getproxy ();
}

@Override
public object invoke (object proxy, Method method, object[] args) throws Throwable {

Object result = Method.invoke (target, args); Perform business processing

Print Log
Logger.info ("____invoke method:" + method.getname ()
+ "; Args: "+ (null = = args?") Null ": Arrays.aslist (args). toString ())
+ "; return: "+ result";

return result;
}

Public Object Gettarget () {
return target;
}

public void Settarget (Object target) {
This.target = target;
}

Public Object GetProxy () {
return proxy;
}

public void SetProxy (Object proxy) {
This.proxy = proxy;
}
}

And then write a test class testing:

Copy Code code as follows:

/**


* Created with IntelliJ idea.


* Author:wangjie email:tiantian.china.2@gmail.com


* date:13-9-24


* Time: 9:54


*/


public class Test {


public static Logger Logger = Logger.getlogger (Test.class.getSimpleName ());


public static void Main (string[] args) {

Bussinessservice bs = loginvohandler.getproxyinstance (Bussinessserviceimpl.class);
Bs.login ("Zhangsan", "123456");
Bs.find ();

Logger.info ("--------------------------------------");

Workservice ws = Loginvohandler.getproxyinstance (Workserviceimpl.class);
Ws.work ();
Ws.sleep ();

Logger.info ("--------------------------------------");

Bussinessservice BSS = loginvohandler.getproxyinstance (Bussinessserviceimpl.class);
Bss.login ("Lisi", "654321");
Bss.find ();

}
}

You will need to add a new business logic Xxxservice later, just call

Xxxservice xs = loginvohandler.getproxyinstance (xxxserviceimpl.class);

Can.

You can also mimic the configuration of a framework such as spring and configure the Bean's class name in an XML file, such as:

<bean id= "Bussinessservice" class= "Com.wangjie.aoptest2.service.impl.BussinessServiceImpl" >

Then parsing the XML in Java code, by Class.forName ("Com.wangjie.aoptest2.service.impl.BussinessServiceImpl"), and getting the class object

Then through Loginvohandler.getproxyinstance (Class.forName ("Com.wangjie.aoptest2.service.impl.BussinessServiceImpl")); Get proxy object Proxy

Then use reflection to invoke the method of the proxy object.

The results of the operation are as follows:

September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:login; args: [Zhangsan, 123456]; Return:login success


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:find; Args:null; Return:find success


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.Test Main


INFO:--------------------------------------


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:work; Args:null; Return:work success


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:sleep; Args:null; Return:sleep success


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.Test Main


INFO:--------------------------------------


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:login; args: [Lisi, 654321]; Return:login success


September 24, 2013 11:08:03 a.m. Com.wangjie.aoptest2.invohandler.LogInvoHandler invoke


INFO: ____invoke method:find; Args:null; Return:find success