最近做一项目，有很多地方得用到网络数据传输与解析，这里采用的是Json方式，它与传统的XML解析方式比起来，有自己的一些优点，首先，它是比XML更轻量级，再一个，写一个XML文件是个烦人的事儿，而Json则相对轻松些。

????????? Android平台有Jsong相关的类来进行Json数据解析，悲剧的是，它们是Android SDK3.0以后才能用的。不过在谷歌网站：http://code.google.com/p/google-gson/里有一个名为Gson的类库，可以用它来解析Json数据，并且，Adroid 3.0平台里其实也就是把这一部分直接整合进Android里了。我们要解析Json数据，直接去网站上下载个jar包，导入到工程里，就可以解析Json数据了。

下面有个例子,很清晰的解释了这种工作方式：

先看看两个我自己封装的类：

HttpUtils.java:

public class HttpUtils {   //从服务器端下载到Json数据，也就是个字符串

    public static String getData(String url) throws Exception {

        StringBuilder sb = new StringBuilder();

        HttpClient httpClient = new DefaultHttpClient();

        HttpGet httpGet = new HttpGet(url);

        HttpResponse httpResponse = httpClient.execute(httpGet);

        HttpEntity httpEntity = httpResponse.getEntity();

        if (httpEntity != null) {

            InputStream instream = httpEntity.getContent();

            BufferedReader reader = new BufferedReader(new InputStreamReader(

                    instream));

            String line = null;

            while ((line = reader.readLine()) != null) {

                sb.append(line);

            }

            return sb.toString();

        }

        return null;

    }

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JsonUtils.java:

public class JsonUtils {

    public static List<Student> parseStudentFromJson(String data) {

        Type listType = new TypeToken<LinkedList<Student>>() {

        }.getType();

        Gson gson = new Gson();

        LinkedList<Student> list = gson.fromJson(data, listType);

        return list;

    }

}

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里面的Student是一个JavaBean对象：

public class Student {

    private String name;

    private int age;

    private String id;

 

    public Student() {

        super();

    }

 

    public Student(String name, int age, String id) {

        super();

        this.name = name;

        this.age = age;

        this.id = id;

    }

 

    public String getName() {

        return name;

    }

 

    public void setName(String name) {

        this.name = name;

    }

 

    public int getAge() {

        return age;

    }

 

    public void setAge(int age) {

        this.age = age;

    }

 

    public String getId() {

        return id;

    }

 

    public void setId(String id) {

        this.id = id;

    }

 

}

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public class MainActivity extends Activity {

    private TextView textView;

    private List<Student> list;

 

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        textView = (TextView) findViewById(R.id.textView);

        String data = null;

        try {

            data = HttpUtils

                    .getData("http://10.16.12.165:8080/JsonTest/JsonTestServlet");

        } catch (Exception e) {

            e.printStackTrace();

        }

        String result = "";

        list = JsonUtils.parseStudentFromJson(data);

        for (Student s : list) {

            result += "name: " + s.getName() + "   " + "age: " + s.getAge()

                    + "   " + "id: " + s.getId() + "\n";

        }

        textView.setText(result);

    }

}

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这样就可以获取网络数据并加以解析利用了，运行结果如下：

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