本来已经转贴了.想一想,自己还是再做个笔记吧.印象更深. 好 .....那么 继续
在写好的类中.添加新的功能.一般是怎么做的呢?
1.静态代理
参考代码static-proxy
1)首先写个接口吧
1
package com.zyl.proxy;
2![](/Images/OutliningIndicators/None.gif)
3![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
public interface UserManager
{
4
5
public void addUer(String name,String password);
6
7
public void delUser(String id);
8
9
public void modifyUser(int id, String name, String password);
10
11
}
2)接口类的实现
1
package com.zyl.proxy;
2![](/Images/OutliningIndicators/None.gif)
3![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
public class UserManagerImpl implements UserManager
{
4![](/Images/OutliningIndicators/InBlock.gif)
5![](/Images/OutliningIndicators/InBlock.gif)
6![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void addUer(String name, String password)
{
7
//
添加日志/安全性检查
8
//checksafe();
9
//采用添加代理类的方法会如何?
10
System.out.println("UserManagerImpl.addUser()");
11![](/Images/OutliningIndicators/InBlock.gif)
12
}
13![](/Images/OutliningIndicators/InBlock.gif)
14
@Override
15![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void delUser(String id)
{
16
//
添加日志/安全性检查
17
//checksafe();
18
System.out.println("UserManagerImpl.delUser()");
19
}
20![](/Images/OutliningIndicators/InBlock.gif)
21
@Override
22![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void modifyUser(int id, String name, String password)
{
23
//
添加日志/安全性检查
24
//checksafe();
25
System.out.println("UserManagerImpl.modifyUser()");
26![](/Images/OutliningIndicators/InBlock.gif)
27
}
28
// private void checksafe(){
29
// System.out.println("检查安全性的方法");
30
// }
31
}
比如添加checksafe()方法. 要在每个实现方法中调用checksafe(); (把代码中注释去掉后的效果)
这样做,有人会不满.不希望在实现类中出现其他7788的东西.
那么注释就别去了...加个代理吧.
3)代理类
1
package com.zyl.proxy;
2![](/Images/OutliningIndicators/None.gif)
3![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
public class UserManagerImplProxy implements UserManager
{
4
//通过构造方法
5
private UserManager usermanager;
6![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public UserManagerImplProxy(UserManager usermanager)
{
7
this.usermanager=usermanager;
8
}
9![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void addUer(String name, String password)
{
10
checksafe();
11
usermanager.addUer(name, password);
12
13![](/Images/OutliningIndicators/InBlock.gif)
14
}
15![](/Images/OutliningIndicators/InBlock.gif)
16![](/Images/OutliningIndicators/InBlock.gif)
17![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void delUser(String id)
{
18
checksafe();
19
usermanager.delUser(id);
20
}
21![](/Images/OutliningIndicators/InBlock.gif)
22![](/Images/OutliningIndicators/InBlock.gif)
23![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void modifyUser(int id, String name, String password)
{
24
checksafe();
25
usermanager.modifyUser(id, name, password);
26![](/Images/OutliningIndicators/InBlock.gif)
27
}
28![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
private void checksafe()
{
29
System.out.println("检查安全性的方法");
30
}
31
//代理类的效果: 没有改变真实的实现,添加了需要的功能.可是在代理类中,代码里充斥着checksafe()这样的无关代码
32
//静态代理不适用大量类需要添加功能的项目
33
}
34![](/Images/OutliningIndicators/None.gif)
//代理类的效果: 没有改变真实的实现,添加了需要的功能.可是在代理类中,代码里充斥着checksafe()这样的无关代码;
//静态代理不适用大量类需要添加功能的项目;
// 第3行: 可以看到,代理类UserManagerImplProxy也是实现接口UserManager;
// 第6行:定义构造方法,传入UserManager类型的实例.实现接口的方法(addUser等);
// 在方法中加入安全检查新的方法checksafe()或者日志等7788的方法.
其实大同小异,在代理类中的方法,照样还是要加入添加的方法checksafe();
4)实现client
1
package com.zyl.ooxx;
2![](/Images/OutliningIndicators/None.gif)
3
import com.zyl.proxy.UserManager;
4
import com.zyl.proxy.UserManagerImpl;
5
import com.zyl.proxy.UserManagerImplProxy;
6![](/Images/OutliningIndicators/None.gif)
7![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
public class client
{
8![](/Images/OutliningIndicators/InBlock.gif)
9![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public static void main(String[] args)
{
10
UserManager usermanager =new UserManagerImpl();
11
//采用代理之后
12
UserManagerImplProxy usermanagerimplproxy=new UserManagerImplProxy(usermanager);
13
14
// usermanager.addUer("帅哥", "11");
15
usermanagerimplproxy.addUer("帅哥2", "password");
16
}
17![](/Images/OutliningIndicators/InBlock.gif)
18
}
19![](/Images/OutliningIndicators/None.gif)
打印结果如下:
1
检查安全性的方法
2
UserManagerImpl.addUser()
ok 静态代理就这样.