适配器模式（Adapter Pattern）
适配器模式是就和现实一个样子，给你一个电脑适配器，它就能提供给你一个电源使用的稳定电压，不管外界是多少F，它的输出电压是不变的。
适配器模式分为4个部分
1.功能适配器(定义必须要用接口)
2.对象适配器(进行转换)
3.目标适配对象
4.源适配对象
如图，使用适配器之后，系统对待外来数据和内部数据没啥两样不用做任何更改。
下面就以抓取度娘和谷哥的网页数据来牛刀小试一把。
IHtml 类适配器
BaiduHtmlAdapter、GoogleHtmlAdapter 对象适配器
Html 目标适配对象
BaiduHtml、GoogleHtml 源适配对象
IHtml
package j2se.pattern;
/**
* class Adapter
* @author Lyon Yao
*
*/
public interface IHtml {
public abstract String getTitle();
public abstract String getBody();
}
Html
package j2se.pattern;
/**
* target object
* @author Lyon Yao
*
*/
public class Html implements IHtml {
private String title;
private String body;
/* (non-Javadoc)
* @see j2se.pattern.IHtml#getTitle()
*/
@Override
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
/* (non-Javadoc)
* @see j2se.pattern.IHtml#getBody()
*/
@Override
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
}
GoogleHtml
package j2se.pattern;
import java.util.HashMap;
/**
* source object
* @author Lyon Yao
*
*/
public class GoogleHtml {
protected HashMap<String, Object> data=new HashMap<String, Object>();
public void setTitle(String title){
data.put("title",title);
}
public void setBody(String body){
data.put("body",body);
}
}
BaiduHtml
package j2se.pattern;
/**
* source object
* @author Lyon Yao
*
*/
public class BaiduHtml {
protected String[] data=new String[2];
public void setTitle(String title){
data[0]=title;
}
public void setBody(String body){
data[1]=body;
}
}
GoogleHtmlAdapter
package j2se.pattern;
/**
* object Adapter
* @author Lyon Yao
*
*/
public class GoogleHtmlAdapter extends GoogleHtml implements IHtml {
public GoogleHtmlAdapter(GoogleHtml googleHtml) {
// TODO Auto-generated constructor stub
super.data=googleHtml.data;
}
@Override
public String getTitle() {
// TODO Auto-generated method stub
return super.data.get("title").toString();
}
@Override
public String getBody() {
// TODO Auto-generated method stub
return super.data.get("body").toString();
}
}
BaiduHtmlAdapter
package j2se.pattern;
/**
* object Adapter
* @author Lyon Yao
*
*/
public class BaiduHtmlAdapter extends BaiduHtml implements IHtml{
public BaiduHtmlAdapter(BaiduHtml baiduHtml) {
// TODO Auto-generated constructor stub
super.data=baiduHtml.data;
}
@Override
public String getTitle() {
// TODO Auto-generated method stub
return super.data[0];
}
@Override
public String getBody() {
// TODO Auto-generated method stub
return super.data[1];
}
}
App
package j2se.pattern;
import java.util.ArrayList;
/**
* Client
* @author Lyon Yao
*
*/
public class App {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
java.util.List<IHtml> list=new ArrayList<IHtml>(0);
Html html=new Html();
html.setTitle("this is our html");
list.add(html);
GoogleHtml googleHtml=new GoogleHtml();
googleHtml.setTitle("this is googleHtml");
GoogleHtmlAdapter googleHtmlAdapter=new GoogleHtmlAdapter(googleHtml);
list.add(googleHtmlAdapter);
BaiduHtml baiduHtml=new BaiduHtml();
baiduHtml.setTitle("this is baiduHtml");
BaiduHtmlAdapter baiduHtmlAdapter=new BaiduHtmlAdapter( baiduHtml);
list.add(baiduHtmlAdapter);
for(IHtml iHtml:list){
System.out.println(iHtml.getTitle());
}
}
}
呵呵，大功告成，运行一下看看是不是没有什么问题吧？我们的App只抓title 没做任何更改。