Android访问网络系列之--服务端返回XML或JSON格式数据，Android 进行解析并显示-白红宇

Android访问网络系列之--服务端返回XML或JSON格式数据，Android 进行解析并显示

阅读量：5309 次

发布时间：2019-06-14

本文共 10330 字，大约阅读时间需要 34 分钟。

例子说明：用户通过访问web资源的最新电影资讯，服务器端生成XML或JSON格式数据，返回Android客户端进行显示。

此案例开发需要两个方面 WEB开发和android开发.

一.web开发相对比较简单，只是模拟一下

相关代码如下：

1.实体Bean

package ygc.yxb.domain;/** * 电影资讯实体Bean * @author YXB * */public class News {    private Integer id;              //id    private String title;        //电影名称    private Integer timelenght; //时长            public News() {            }            public News(Integer id, String title, Integer timelenght) {        this.id = id;        this.title = title;        this.timelenght = timelenght;    }    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 getTimelenght() {        return timelenght;    }    public void setTimelenght(Integer timelenght) {        this.timelenght = timelenght;    }        }

2.业务逻辑

package ygc.yxb.service.impl;import java.util.ArrayList;import java.util.List;import ygc.yxb.domain.News;import ygc.yxb.service.VideoNewsService;public class VideoNewsServiceImpl implements VideoNewsService {            /**     * 获取电影资讯的业务方法     */    public List
     
       getLastNews(){                        List
      
        newses = new ArrayList
       
        ();        newses.add(new News(32, "大话西游", 90));        newses.add(new News(12, "轩辕剑", 40));        newses.add(new News(56, "爱情公寓", 30));        return newses;            }}

3.Servlet

package ygc.yxb.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 ygc.yxb.domain.News;import ygc.yxb.service.VideoNewsService;import ygc.yxb.service.impl.VideoNewsServiceImpl;/** * 用最原始的web开发servlet请求服务器，并返回客户端数据 */public class ListServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    private VideoNewsService service = new VideoNewsServiceImpl();       protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doPost(request, response);    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {                List
     
       videos = service.getLastNews();        String format=request.getParameter("format");        //如果用户请求的是这个路径，则返回JSON格式的数据.http://192.168.1.113:8080/videonews/ListServlet?format=json                if("json".equals(format)){            //[{id:56,title:"xxxx",timelength:90}]            //组拼一个JSON格式的对象            StringBuilder builder = new StringBuilder();            builder.append('[');                for (News news : videos) {                    builder.append('{');                        builder.append("id:").append(news.getId()).append(',');                        builder.append("title:\"").append(news.getTitle()).append("\",");                        builder.append("timelength:").append(news.getTimelenght());                    builder.append("},");                }                builder.deleteCharAt(builder.length()-1);            builder.append(']');                        request.setAttribute("json", builder.toString());            request.getRequestDispatcher("/WEB-INF/page/jsonvideonews.jsp").forward(request, response);                                //如果用户请求的是这个路径，则返回XML格式的数据.http://192.168.1.113:8080/videonews/ListServlet        }else{            request.setAttribute("videos", videos);            request.getRequestDispatcher("/WEB-INF/page/videonews.jsp").forward(request, response);        }    }}

4.jsp页面

4.1.jsonvideonews.jsp

<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%>${json}

4.2.videonews.jsp XML数据

<%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
     
         
              
                   
        ${video.title }            
        
         ${video.timelenght}

到此为止web开发完毕，现在Android开发相关代码

1.实体Bean

package ygc.yxb.domain;public class News {    private Integer id;    private String title;    private Integer timelenght;            public News() {            }            public News(Integer id, String title, Integer timelenght) {        this.id = id;        this.title = title;        this.timelenght = timelenght;    }    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 getTimelenght() {        return timelenght;    }    public void setTimelenght(Integer timelenght) {        this.timelenght = timelenght;    }        }

2.业务逻辑

package ygc.yxb.service;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.ArrayList;import java.util.List;import org.json.JSONArray;import org.json.JSONObject;import org.xmlpull.v1.XmlPullParser;import android.util.Xml;import ygc.yxb.domain.News;import ygc.yxb.utils.StreamTool;public class VideoNewsService {        /**     * 获取最新的视频资讯接受服务器端XML格式的数据     * @return     * @throws Exception     */    public static List
     
       getLastNews() throws Exception{        String path="http://192.168.1.113:8080/videonews/ListServlet";        URL url = new URL(path);        HttpURLConnection conn = (HttpURLConnection)url.openConnection();        conn.setConnectTimeout(5000);        conn.setRequestMethod("GET");        if(conn.getResponseCode()==200){            InputStream inStream=conn.getInputStream();            return parseXML(inStream);        }        return null;    }        /**     * 获取最新的视频资讯 接受服务器端JSON格式的数据     * @return     * @throws Exception     */    public static List
      
        getJSONLastNews() throws Exception{        String path="http://192.168.1.113:8080/videonews/ListServlet?format=json";        URL url = new URL(path);        HttpURLConnection conn = (HttpURLConnection)url.openConnection();        conn.setConnectTimeout(5000);        conn.setRequestMethod("GET");        if(conn.getResponseCode()==200){            InputStream inStream=conn.getInputStream();            return parseJSON(inStream);        }        return null;    }    /**     * 解析JSON数据     * @param inStream     * @return     */    private static List
       
         parseJSON(InputStream inStream) throws Exception {        List
        
          newses = new ArrayList
         
          ();        byte[] data =StreamTool.read(inStream);        //将字节数组转换成字符串        String json= new String(data);        //将json对象转换成json的数组对象        JSONArray array = new JSONArray(json);        for (int i = 0; i < array.length(); i++) {            JSONObject jsonObject=array.getJSONObject(i);            News news=new News(jsonObject.getInt("id"),jsonObject.getString("title"),jsonObject.getInt("timelength"));            newses.add(news);        }                return newses;    }    /**     * 解析服务器返回的XML数据     * @param inStream     * @return     */    private static List
          
            parseXML(InputStream inStream) throws Exception{ List
           
             newses = new ArrayList
            
             (); News news = null; //用Pull解析器解析XML文件 XmlPullParser parser= Xml.newPullParser(); parser.setInput(inStream, "UTF-8"); //得到开始文档XML事件 int event = parser.getEventType(); //不等于结束事件，循环读取XML文件并封装成对象 while(event !=XmlPullParser.END_DOCUMENT){ switch (event) { case XmlPullParser.START_TAG: if("news".equals(parser.getName())){ int id = new Integer(parser.getAttributeValue(0)); news = new News(); news.setId(id); }else if("title".equals(parser.getName())){ news.setTitle(parser.nextText()); }else if("timelength".equals(parser.getName())){ news.setTimelenght(new Integer(parser.nextText())); } break; case XmlPullParser.END_TAG: if("news".equals(parser.getName())){ newses.add(news); news = null; } break; } event = parser.next(); } return newses; } }

3.Activity

package ygc.yxb.news;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import ygc.yxb.domain.News;import ygc.yxb.service.VideoNewsService;import android.app.Activity;import android.os.Bundle;import android.widget.ListView;import android.widget.SimpleAdapter;public class MainActivity extends Activity {    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                ListView listView=(ListView)this.findViewById(R.id.listView);                try {            List
     
       videos=VideoNewsService.getJSONLastNews();            List
      
       
        > data = new ArrayList
        
         
          >();            for (News news : videos) {                HashMap
          
            item = new HashMap
           
            (); item.put("id", news.getId()); item.put("title", news.getTitle()); item.put("timelength", getResources().getString(R.string.timelength)+ news.getTimelenght()+getResources().getString(R.string.min)); data.add(item); } //用SimpleAdapter 绑定ListView控件 SimpleAdapter adapter = new SimpleAdapter(this,data, R.layout.item,new String[]{"title","timelength"}, new int[]{R.id.title,R.id.timelength}); listView.setAdapter(adapter); } catch (Exception e) { e.printStackTrace(); } }}

4读取数据流工具类:

package ygc.yxb.utils;import java.io.ByteArrayOutputStream;import java.io.InputStream;public class StreamTool {    /**     * 读取流中的数据     * @param inStream     * @return     * @throws Exception     */    public static byte[] read(InputStream inStream) throws Exception {        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();        byte[] buffer = new byte[1024];        int len = 0;        //如果字节流中的数据不等于-1，就说明一直有，然后循环读出        while( (len=inStream.read(buffer)) !=-1){            //将读出的数据放入内存中            outputStream.write(buffer);                    }        inStream.close();        return outputStream.toByteArray();    }}

这里android 开发完毕，而显示的控件是ListView 最后在清单文件中，配置访问网络的权限即可。

运行效果如下：