Android 进行解析并显示服务端返回的数据

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

1. package ygc.yxb.domain;[/font]
2. /**
3. * 电影资讯实体Bean
4. * @author YXB
5. *
6. */
7. public class News {
8. private Integer id;              //id
9. private String title;        //电影名称
10. private Integer timelenght; //时长
11. public News() {
12. }
13. public News(Integer id, String title, Integer timelenght) {
14. this.id = id;
15. this.title = title;
16. this.timelenght = timelenght;
17. }
18. public Integer getId() {
19. return id;
20. }
21. public void setId(Integer id) {
22. this.id = id;
23. }
24. public String getTitle() {
25. return title;
26. }
27. public void setTitle(String title) {
28. this.title = title;
29. }
30. public Integer getTimelenght() {
31. return timelenght;
32. }
33. public void setTimelenght(Integer timelenght) {
34. this.timelenght = timelenght;
35. }

2.业务逻辑

1. package ygc.yxb.service.impl;[/font]
2. import java.util.ArrayList;
3. import java.util.List;[/font]
4. import ygc.yxb.domain.News;
5. import ygc.yxb.service.VideoNewsService;[/font]
6. public class VideoNewsServiceImpl implements VideoNewsService {
7. /**
8. * 获取电影资讯的业务方法
9. */
10. public List<News> getLastNews(){
11. List<News> newses = new ArrayList<News>();
12. newses.add(new News(32, "大话西游", 90));
13. newses.add(new News(12, "轩辕剑", 40));
14. newses.add(new News(56, "爱情公寓", 30));
15. return newses;
16. }

3.Servlet

1. package ygc.yxb.servlet;[/font]
2. import java.io.IOException;
3. import java.util.List;[/font]
4. import javax.servlet.ServletException;
5. import javax.servlet.http.HttpServlet;
6. import javax.servlet.http.HttpServletRequest;
7. import javax.servlet.http.HttpServletResponse;[/font]
8. import ygc.yxb.domain.News;
9. import ygc.yxb.service.VideoNewsService;
10. import ygc.yxb.service.impl.VideoNewsServiceImpl;[/font]
11. /**
12. * 用最原始的web开发servlet请求服务器，并返回客户端数据
13. */
14. public class ListServlet extends HttpServlet {
15. private static final long serialVersionUID = 1L;
16. private VideoNewsService service = new VideoNewsServiceImpl();
17. protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
18. doPost(request, response);
19. }
20. protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
21. List<News> videos = service.getLastNews();
22. String format=request.getParameter("format");
23. //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
24. if("json".equals(format)){
25. //[{id:56,title:"xxxx",timelength:90}]
26. //组拼一个JSON格式的对象
27. StringBuilder builder = new StringBuilder();
28. builder.append('[');
29. for (News news : videos) {
30. builder.append('{');
31. builder.append("id:").append(news.getId()).append(',');
32. builder.append("title:\"").append(news.getTitle()).append("\",");
33. builder.append("timelength:").append(news.getTimelenght());
34. builder.append("},");
35. }
36. builder.deleteCharAt(builder.length()-1);
37. builder.append(']');
38. request.setAttribute("json", builder.toString());
39. request.getRequestDispatcher("/WEB-INF/page/jsonvideonews.jsp").forward(request, response);
40. //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
41. }else{
42. request.setAttribute("videos", videos);
43. request.getRequestDispatcher("/WEB-INF/page/videonews.jsp").forward(request, response);
44. }
45. }

4.jsp页面
4.1.jsonvideonews.jsp

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

4.2.videonews.jsp XML数据

1. <%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><[url=mailto:%@taglib]%@taglib[/url] uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><?xml version="1.0" encoding="UTF-8"?>
2. <videonews>
3. <c:forEach items="${videos}" var="video">
4. <news id ="${video.id }">
5. <title>${video.title }</title>
6. <timelength>${video.timelenght}</timelength>
7. </news>
8. </c:forEach>
9. </videonews>

到此为止web开发完毕，现在Android开发相关代码 1.实体Bean

1. package ygc.yxb.domain;
2. public class News {
3. private Integer id;
4. private String title;
5. private Integer timelenght;
6. public News() {
7. }
8. public News(Integer id, String title, Integer timelenght) {
9. this.id = id;
10. this.title = title;
11. this.timelenght = timelenght;
12. }
13. public Integer getId() {
14. return id;
15. }
16. public void setId(Integer id) {
17. this.id = id;
18. }
19. public String getTitle() {
20. return title;
21. }
22. public void setTitle(String title) {
23. this.title = title;
24. }
25. public Integer getTimelenght() {
26. return timelenght;
27. }
28. public void setTimelenght(Integer timelenght) {
29. this.timelenght = timelenght;
30. }
31. }

2.业务逻辑

1. package ygc.yxb.service;
2. import java.io.InputStream;
3. import java.net.HttpURLConnection;
4. import java.net.URL;
5. import java.util.ArrayList;
6. import java.util.List;
7. import org.json.JSONArray;
8. import org.json.JSONObject;
9. import org.xmlpull.v1.XmlPullParser;
10. import android.util.Xml;
11. import ygc.yxb.domain.News;
12. import ygc.yxb.utils.StreamTool;
13. public class VideoNewsService {
14. /**
15. * 获取最新的视频资讯接受服务器端XML格式的数据
16. * @return
17. * @throws Exception
18. */
19. public static List<News> getLastNews() throws Exception{
20. String path="http://192.168.1.113:8080/videonews/ListServlet";
21. URL url = new URL(path);
22. HttpURLConnection conn = (HttpURLConnection)url.openConnection();
23. conn.setConnectTimeout(5000);
24. conn.setRequestMethod("GET");
25. if(conn.getResponseCode()==200){
26. InputStream inStream=conn.getInputStream();
27. return parseXML(inStream);
28. }
29. return null;
30. }
31. /**
32. * 获取最新的视频资讯 接受服务器端JSON格式的数据
33. * @return
34. * @throws Exception
35. */
36. public static List<News> getJSONLastNews() throws Exception{
37. String path="http://192.168.1.113:8080/videonews/ListServlet?format=json";
38. URL url = new URL(path);
39. HttpURLConnection conn = (HttpURLConnection)url.openConnection();
40. conn.setConnectTimeout(5000);
41. conn.setRequestMethod("GET");
42. if(conn.getResponseCode()==200){
43. InputStream inStream=conn.getInputStream();
44. return parseJSON(inStream);
45. }
46. return null;
47. }
48. /**
49. * 解析JSON数据
50. * @param inStream
51. * @return
52. */
53. private static List<News> parseJSON(InputStream inStream) throws Exception {
54. List<News> newses = new ArrayList<News>();
55. byte[] data =StreamTool.read(inStream);
56. //将字节数组转换成字符串
57. String json= new String(data);
58. //将json对象转换成json的数组对象
59. JSONArray array = new JSONArray(json);
60. for (int i = 0; i < array.length(); i++) {
61. JSONObject jsonObject=array.getJSONObject(i);
62. News news=new News(jsonObject.getInt("id"),jsonObject.getString("title"),jsonObject.getInt("timelength"));
63. newses.add(news);
64. }
65. return newses;
66. }
67. /**
68. * 解析服务器返回的XML数据
69. * @param inStream
70. * @return
71. */
72. private static List<News> parseXML(InputStream inStream) throws Exception{
73. List<News> newses = new ArrayList<News>();
74. News news = null;
75. //用Pull解析器解析XML文件
76. XmlPullParser parser= Xml.newPullParser();
77. parser.setInput(inStream, "UTF-8");
78. //得到开始文档XML事件
79. int event = parser.getEventType();
80. //不等于结束事件，循环读取XML文件并封装成对象
81. while(event !=XmlPullParser.END_DOCUMENT){
82. switch (event) {
83. case XmlPullParser.START_TAG:
84. if("news".equals(parser.getName())){
85. int id = new Integer(parser.getAttributeValue(0));
86. news = new News();
87. news.setId(id);
88. }else if("title".equals(parser.getName())){
89. news.setTitle(parser.nextText());
90. }else if("timelength".equals(parser.getName())){
91. news.setTimelenght(new Integer(parser.nextText()));
92. }
93. break;
94. case XmlPullParser.END_TAG:
95. if("news".equals(parser.getName())){
96. newses.add(news);
97. news = null;
98. }
99. break;
100. }
101. event = parser.next();
102. }
103. return newses;
104. }
105. }

3.Activity

1. package ygc.yxb.news;
2. import java.util.ArrayList;
3. import java.util.HashMap;
4. import java.util.List;
5. import ygc.yxb.domain.News;
6. import ygc.yxb.service.VideoNewsService;
7. import android.app.Activity;
8. import android.os.Bundle;
9. import android.widget.ListView;
10. import android.widget.SimpleAdapter;
11. public class MainActivity extends Activity {
12. /** Called when the activity is first created. */
13. @Override
14. public void onCreate(Bundle savedInstanceState) {
15. super.onCreate(savedInstanceState);
16. setContentView(R.layout.main);
17. ListView listView=(ListView)this.findViewById(R.id.listView);
18. try {
19. List<News> videos=VideoNewsService.getJSONLastNews();
20. List<HashMap<String,Object>> data = new ArrayList<HashMap<String,Object>>();
21. for (News news : videos) {
22. HashMap<String, Object> item = new HashMap<String, Object>();
23. item.put("id", news.getId());
24. item.put("title", news.getTitle());
25. item.put("timelength", getResources().getString(R.string.timelength)+
26. news.getTimelenght()+getResources().getString(R.string.min));
27. data.add(item);
28. }
29. //用SimpleAdapter 绑定ListView控件
30. SimpleAdapter adapter = new SimpleAdapter(this,data,
31. R.layout.item,new String[]{"title","timelength"},
32. new int[]{R.id.title,R.id.timelength});
33. listView.setAdapter(adapter);
34. } catch (Exception e) {
35. e.printStackTrace();
36. }
37. }
38. }

4读取数据流工具类:

1. package ygc.yxb.utils;
2. import java.io.ByteArrayOutputStream;
3. import java.io.InputStream;
4. public class StreamTool {
5. /**
6. * 读取流中的数据
7. * @param inStream
8. * @return
9. * @throws Exception
10. */
11. public static byte[] read(InputStream inStream) throws Exception {
12. ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
13. byte[] buffer = new byte[1024];
14. int len = 0;
15. //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
16. while( (len=inStream.read(buffer)) !=-1){
17. //将读出的数据放入内存中
18. outputStream.write(buffer);
19. }
20. inStream.close();
21. return outputStream.toByteArray();
22. }
23. }

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。