Android中数据文件解析（Json解析【从服务器端获取数据并且解析，显示在客户端上面】）

首先说一下Json数据的最基本的特点，Json数据是一系列的键值对的集合,和XML数据来比，Json数据的体积更加小，传输效率高，易解析，不过可读性不高;

因为这次要从服务器端得到Json数据，并且通过解析之后把解析后的数据显示在Android客户端中，首先部署服务器端代码(直接使用Jsp/Servlet):

构造的Json数据如下:

[{"name":"张三","address":"北京","age":20},{"name":"李四","address":"上海","age":30},{"name":"王五","address":"深圳","age":35}]

[一]服务器端(Person.java省略):

①:数据构造JsonService.java

1. public class JsonService {
   
2. public static List getListPerson() {
   
3. List mLists = new ArrayList();
   
4. mLists.add(new Person("张三", "北京", 20));
   
5. mLists.add(new Person("李四", "上海", 30));
   
6. mLists.add(new Person("王五", "深圳", 35));
   
7. return mLists;
   
8. }

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②:Servlet的代码（包括构造Json数据，没有使用Json数据转换方法）JsonServlet.java

1. public void doGet(HttpServletRequest request, HttpServletResponse response)
   
2. throws ServletException, IOException {
   
3. response.setContentType("text/html");
   
4. response.setCharacterEncoding("UTF-8");
   
5. PrintWriter out = response.getWriter();
   
6. List persons = JsonService.getListPerson();
   
7. StringBuffer sb = new StringBuffer();
   
8. sb.append('[');
   
9. for (Person person : persons) {
   
10. sb.append('{').append("\"name\":").append("\""+person.getName()+"\"").append(
    
11. ",");
    
12. sb.append("\"address\":").append("\""+person.getAddress()+"\"").append(",");
    
13. sb.append("\"age\":").append(person.getAge());
    
14. sb.append('}').append(",");
    
15. }
    
16. sb.deleteCharAt(sb.length() - 1);
    
17. sb.append(']');
    
18. out.write(new String(sb));
    
19. out.flush();
    
20. out.close();
    
21. }

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1. 
   

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③:部署到Tomact 浏览器输入http://localhost/JsonWeb/JsonServlet直接访问结果如下:

2012-3-15 09:13:51 上传

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至此服务器端代码编码完成，下面进行客户端代码编写; (二)客户端(Person类，和展示数据的布局文件因为简单省去)
①:获取服务器端的Json数据并且解析的工具类JsonParse.java
必要的需要导入的包省去

1. public class JsonParse {
   
2. /**
   
3. * 解析Json数据
   
4. *
   
5. * @param urlPath
   
6. * @return mlists
   
7. * @throws Exception
   
8. */
   
9. public static List getListPerson(String urlPath) throws Exception {
   
10. List mlists = new ArrayList();
    
11. byte[] data = readParse(urlPath);
    
12. JSONArray array = new JSONArray(new String(data));
    
13. for (int i = 0; i < array.length(); i++) {
    
14. JSONObject item = array.getJSONObject(i);
    
15. String name = item.getString("name");
    
16. String address = item.getString("address");
    
17. int age = item.getInt("age");
    
18. mlists.add(new Person(name, address, age));
    
19. }
    
20. return mlists;
    
21. }
    
22. /**
    
23. * 从指定的url中获取字节数组
    
24. *
    
25. * @param urlPath
    
26. * @return 字节数组
    
27. * @throws Exception
    
28. */
    
29. public static byte[] readParse(String urlPath) throws Exception {
    
30. ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    
31. byte[] data = new byte[1024];
    
32. int len = 0;
    
33. URL url = new URL(urlPath);
    
34. HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    
35. InputStream inStream = conn.getInputStream();
    
36. while ((len = inStream.read(data)) != -1) {
    
37. outStream.write(data, 0, len);
    
38. }
    
39. inStream.close();
    
40. return outStream.toByteArray();
    
41. }
    
42. }

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②:主Activity类

1. public class MainActivity extends Activity {
   
2. private Button mButton;
   
3. private ListView mListView;
   
4. //使用IP不能使用localhost或者127.0.0.1，因为android模拟器默认绑定这个IP，这里应该访问局域网IP
   
5. private static final String urlPath = "http://10.16.31.207/JsonWeb/JsonServlet";
   
6. private static final String TAG = "MainActivity";
   
7. private List persons;
   
8. @Override
   
9. public void onCreate(Bundle savedInstanceState) {
   
10. super.onCreate(savedInstanceState);
    
11. setContentView(R.layout.main);
    
12. mButton = (Button) findViewById(R.id.button1);
    
13. mListView = (ListView) findViewById(R.id.listView1);
    
14. mButton.setOnClickListener(new MyOnClickListener());
    
15. }
    
16. 
    
17. private class MyOnClickListener implements OnClickListener {
    
18. @Override
    
19. public void onClick(View v) {
    
20. try {
    
21. // 得到Json解析成功之后数据
    
22. persons = JsonParse.getListPerson(urlPath);
    
23. List> data = new ArrayList>();
    
24. for (int i = 0; i < persons.size(); i++) {
    
25. HashMap map = new HashMap();
    
26. map.put("name", persons.get(i).getName());
    
27. map.put("address", persons.get(i).getAddress());
    
28. map.put("age", persons.get(i).getAge());
    
29. data.add(map);
    
30. }
    
31. //初始化适配器，并且绑定数据
    
32. SimpleAdapter _Adapter = new SimpleAdapter(MainActivity.this,
    
33. data, R.layout.listview_item, new String[] { "name",
    
34. "address", "age" }, new int[] { R.id.textView1,
    
35. R.id.textView2, R.id.textView3 });
    
36. mListView.setAdapter(_Adapter);
    
37. } catch (Exception e) {
    
38. Toast.makeText(MainActivity.this, "解析失败", 2000).show();
    
39. Log.i(TAG, e.toString());
    
40. 
    
41. }
    
42. }
    
43. }

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至此服务器端和客户端编码介绍，运行android应用结果截图:

转自:http://www.apkbus.com/android-24098-1-1.html