【Android开发】XML传送网络信息

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简述

此技术结合JSP技术,在JSP上的数据,可以用XML传输到安卓客户端,然后用户用手机查询WEB应用上的信息(可以看到数据库保存的讯息)

学到的东西:

如何从网络中得到自定义的数据,得到自定义数据后,又如何完成对它的解析,然后显示出来

WEB应用部分

首先是WEB应用部分,写的是一个视屏网站中视频的信息,为了方便看,没有加入数据库数据,只是自己定义了一些数据来测试:

采用JSP写的WEB应用:

Servlet代码

package deu.hpu.servlet;
 
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import deu.hpu.servise.dima.News;
import deu.hpu.servise.impl.VideoNewsService;
import deu.hpu.servise.impl.VideoNewsServiceImpl;
 
public class ListServlet extends HttpServlet {
    private VideoNewsService service=new VideoNewsServiceImpl();
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException {
        doPost(request,response);
}
 
public void doPost(HttpServletRequest request,IOException {
          //得到所有的视频信息
           List<News> videos=service.getLastNews();
           //把视频信息放在request上
           request.setAttribute("videos",videos);
           //转发至videonews.jsp界面(一个XML)
           request.getRequestDispatcher("/WEB-INF/Page/videonews.jsp").forward(request,response);
}
 
}


JSP界面(其实是一个XML

//注意<?xmlversion="1.0"encoding="UTF-8"?>一定要写在第一行

//此处采用了jstl标签解析技术(详情请看http://blog.csdn.net/acmman/article/details/38750809

//jstl标签解析技术必须导入jstl.jarstandard.jar

<%@ page language="java" import="java.util.*" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><?xml version="1.0" encoding="UTF-8"?><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<videonews><c:forEach items="${videos}" var="video">
<news id="${video.id}">
<title>${video.title}</title>
<timelength>${video.timelength}</timelength>
</news>
</c:forEach>
</videonews>


业务类VideoNewsService接口

package deu.hpu.servise.impl;
 
import java.util.List;
 
import deu.hpu.servise.dima.News;
 
public interface VideoNewsService {
   /*
    * 获取最新视频资讯
    * */
public abstract List<News> getLastNews();
 
}
业务类VideoNewsServiceImpl实现类
package deu.hpu.servise.impl;
 
import java.util.ArrayList;
import java.util.List;
 
import deu.hpu.servise.dima.News;
 
public class VideoNewsServiceImpl implements VideoNewsService {
    public List<News> getLastNews(){
    	 List<News> newses=new ArrayList<News>();
    	 newses.add(new News(12,"古剑奇谭",90));
    	 newses.add(new News(45,"万万没想到",45));
    	 newses.add(new News(89,"超验骇客",120));
    	 return newses;
     }
     
}

News的类

package deu.hpu.servise.dima;
 
public class News {
    private Integer id;
    private String title;
    private Integer timelength;
 
public News(){}
public News(Integer id,String title,Integer timelength) {
super();
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;
}
    
}

一个简单的WEB应用出来了,在浏览器访问Servlet效果

Android客户端部分

主界面布局:

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <ListView 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/listView"
    />
</LinearLayout>


列表元素ListView的布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >
    <TextView 
    android:layout_width="230dp"
    android:layout_height="wrap_content"
    android:id="@+id/title"
        />
    <TextView 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/timelength"
        />
</LinearLayout> 


MainActivity.java

package com.example.vedionewses;
 
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
 
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import deu.hpu.servise.dima.News;
import en.deu.service.VideoService;
 
public class MainActivity extends Activity {
 
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ListView listview=(ListView) findViewById(R.id.listView);
try {
List<News> videos=VideoService.getLastNews();
List<HashMap<String,Object>> data=new ArrayList<HashMap<String,Object>>();
for(News news:videos){
HashMap<String,Object> item=new HashMap<String,Object>();
item.put("id",news.getid());
item.put("title",news.getTitle());
item.put("timelength",news.getTimelength());
data.add(item);
}
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) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
 
}
 


上面出现的VideoService类以及其方法(其中用XML解析器解析传来的XML文件

package en.deu.service;
 
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
 
import org.xmlpull.v1.XmlPullParser;
 
import android.util.Xml;
 
import deu.hpu.servise.dima.News;
 
public class VideoService {
/*
 * 获取最新的视频资讯
 * */
     public static List<News> getLastNews() throws Exception{
    	 String path="http://10.20.124.72:8080/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;
     }
    /*
     * 解析服务器返回的XML数据
     * */
     
     //parser.getName()得到字段的名称,parser.getText()得到字段的内容
     /*如<news id="12">
     <title>古剑奇谭</title>
     <timelength>90</timelength>
     </news>
     parser.getName()可以得到news、title、timelength
     parser.getText()可以得到title、timelength中的“古剑奇谭”和90
     */
private static List<News> parseXML(InputStream instream) throws Exception{
List<News> newses=new ArrayList<News>();
News news=null;
//par技术,通过安卓提供的工具类new一个XML破解器
XmlPullParser parser=Xml.newPullParser();
parser.setInput(instream,"UTF-8");
//得到开始文档事件
int event=parser.getEventType();
//循环,让它不断的进入后面的节点
//只要不等于文档的结束事件,就不断的循环
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.setTimelength(new Integer(parser.nextText()));
}
break;
case XmlPullParser.END_TAG:
if("news".equals(parser.getName())){
//把这一组的new给添加到ArrayList<News>容器中
newses.add(news);
//将news清空,准备下一组
news=null;
}
break;
default:
break;
}
event=parser.next();
}
return newses;
}
}
 

这里也有一个News类,和WEB应用中的一模一样,就不再写了

最后要在配置文件AndroidMainifest.xml中加入访问internet的权限,不然手机访问不了网络:

<uses-permission android:name="android.permission.INTERNET"/>

运行虚拟机,效果如下:

原文链接:https://www.f2er.com/xml/298135.html

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