前面学习过了使用SAX解析XML数据(点击进入:SAX解析XML数据),今天学习Json解析；
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
public class JsonService { public static List<Person> getListPerson() { List<Person> mLists = new ArrayList<Person>(); mLists.add(new Person("张三", "北京", 20)); mLists.add(new Person("李四", "上海", 30)); mLists.add(new Person("王五", "深圳", 35)); return mLists; } 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 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); response.setCharacterEncoding("UTF-8"); PrintWriter out = response.getWriter(); List<Person> persons = JsonService.getListPerson(); StringBuffer sb = new StringBuffer(); sb.append('['); for (Person person : persons) { sb.append('{').append("\"name\":").append("\""+person.getName()+"\"").append( ","); sb.append("\"address\":").append("\""+person.getAddress()+"\"").append(","); sb.append("\"age\":").append(person.getAge()); sb.append('}').append(","); } sb.deleteCharAt(sb.length() - 1); sb.append(']'); out.write(new String(sb)); out.flush(); out.close(); } ③:部署到Tomact 浏览器输入http://localhost/JsonWeb/JsonServlet直接访问结果如下: 
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
public class JsonParse { /** * 解析Json数据 * * @param urlPath * @return mlists * @throws Exception */ public static List<Person> getListPerson(String urlPath) throws Exception { List<Person> mlists = new ArrayList<Person>(); byte[] data = readParse(urlPath); JSONArray array = new JSONArray(new String(data)); for (int i = 0; i < array.length(); i++) { JSONObject item = array.getJSONObject(i); String name = item.getString("name"); String address = item.getString("address"); int age = item.getInt("age"); mlists.add(new Person(name, address, age)); } return mlists; } /** * 从指定的url中获取字节数组 * * @param urlPath * @return 字节数组 * @throws Exception */ public static byte[] readParse(String urlPath) throws Exception { ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] data = new byte[1024]; int len = 0; URL url = new URL(urlPath); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); InputStream inStream = conn.getInputStream(); while ((len = inStream.read(data)) != -1) { outStream.write(data, 0, len); } inStream.close(); return outStream.toByteArray(); } } ②:主Activity类
public class MainActivity extends Activity { private Button mButton; private ListView mListView; //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 private static final String urlPath = "http://10.16.31.207/JsonWeb/JsonServlet"; private static final String TAG = "MainActivity"; private List<Person> persons; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mButton = (Button) findViewById(R.id.button1); mListView = (ListView) findViewById(R.id.listView1); mButton.setOnClickListener(new MyOnClickListener()); } private class MyOnClickListener implements OnClickListener { @Override public void onClick(View v) { try { // 得到Json解析成功之后数据 persons = JsonParse.getListPerson(urlPath); List<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>(); for (int i = 0; i < persons.size(); i++) { HashMap<String, Object> map = new HashMap<String, Object>(); map.put("name", persons.get(i).getName()); map.put("address", persons.get(i).getAddress()); map.put("age", persons.get(i).getAge()); data.add(map); } //初始化适配器，并且绑定数据 SimpleAdapter _Adapter = new SimpleAdapter(MainActivity.this, data, R.layout.listview_item, new String[] { "name", "address", "age" }, new int[] { R.id.textView1, R.id.textView2, R.id.textView3 }); mListView.setAdapter(_Adapter); } catch (Exception e) { Toast.makeText(MainActivity.this, "解析失败", 2000).show(); Log.i(TAG, e.toString()); } } }
至此服务器端和客户端编码介绍，运行android应用结果截图:
源代码下载链接:http://download.csdn.net/detail/jiangqq781931404/4087194
