获取服务器上格式为JSON和XML两种格式的信息的小程序

首先写一个应用服务器端的jsp程序，用jsp和servlet简单实现，如下图所示

[java]
package cn.roco.domain;

public class News {
    private Integer id;
    private String title;
    private Integer timelength;

    public News() {
    }

    public News(Integer id, String title, Integer timelength) {
        this.id = id;
        this.title = title;
        this.timelength = timelength;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Integer getTimelength() {
        return timelength;
    }

    public void setTimelength(Integer timelength) {
        this.timelength = timelength;
    }

}

package cn.roco.domain;

public class News {
private Integer id;
private String title;
private Integer timelength;

public News() {
}

public News(Integer id, String title, Integer timelength) {
  this.id = id;
  this.title = title;
  this.timelength = timelength;
}

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public Integer getTimelength() {
return timelength;
}

public void setTimelength(Integer timelength) {
this.timelength = timelength;
}

}

[java]
package cn.roco.service;

import java.util.List;

import cn.roco.domain.News;

public interface VideoNewsService {

    /**
     * 获取最新视频资讯
     * @return
     */
    public List<News> getLastNews();

}

package cn.roco.service;

import java.util.List;

import cn.roco.domain.News;

public interface VideoNewsService {

/**
* 获取最新视频资讯
* @return
*/
public List<News> getLastNews();

}

[java]
package cn.roco.service.impl;

import java.util.ArrayList;
import java.util.List;

import cn.roco.domain.News;
import cn.roco.service.VideoNewsService;

public class VideoNewsServiceBean implements VideoNewsService{
    /**
     * 模拟从服务器中获取数据返回
     */
    public List<News> getLastNews(){
        List<News> newses=new ArrayList<News>();
        for (int i = 1; i < 30; i++) {
            newses.add(new News(i,"Xili"+i,i+90));
        }
        return newses;
    }
}

package cn.roco.service.impl;

import java.util.ArrayList;
import java.util.List;

import cn.roco.domain.News;
import cn.roco.service.VideoNewsService;

public class VideoNewsServiceBean implements VideoNewsService{
/**
* 模拟从服务器中获取数据返回
*/
public List<News> getLastNews(){
  List<News> newses=new ArrayList<News>();
  for (int i = 1; i < 30; i++) {
   newses.add(new News(i,"Xili"+i,i+90));
  }
  return newses;
}
}

[java]
package cn.roco.servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.roco.domain.News;
import cn.roco.service.VideoNewsService;
import cn.roco.service.impl.VideoNewsServiceBean;

public class ListServlet extends HttpServlet {

    private VideoNewsService newsService=new VideoNewsServiceBean();

    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        List<News> videos=newsService.getLastNews();
        String format=req.getParameter("format");
        //返回JSON格式
        if ("json".equals(format)) {
            StringBuilder builder=new StringBuilder();
            builder.append('[');
            for (News news : videos) {
                builder.append('{');
                builder.append("id:").append(news.getId()).append(',');
                //转义 ""双引号
                builder.append("title:\"").append(news.getTitle()).append("\",");

补充：web前端 , JavaScript ,