findViewById(R.id.parseBtn).setOnClickListener(new OnClickListener(){
  @Override
  public void onClick(View v) {
    jsonData = "[{\"name\":\"Michael\",\"age\":20},{\"name\":\"Mike\",\"age\":21}]";
    MainActivity.parseJson(jsonData);
  }
});
public static void parseJson(String jsonStr){
  //如果要解析JSON数据，首先要有一个JsonReader对象
  JsonReader jsonReader = new JsonReader(new StringReader(jsonStr));
  try {
  //开始遍历数组（多个JSON对象）
    jsonReader.beginArray();
    while(jsonReader.hasNext()){
    //开始遍历JSON对象(含有多个属性)
      jsonReader.beginObject();
      while(jsonReader.hasNext()){
        String tagName = jsonReader.nextName();
        if(tagName.equals("name")){
          System.out.println("name --> " + jsonReader.nextString());
        }else if(tagName.equals("age")){
          System.out.println("age --> " + jsonReader.nextString());
        }
      }
    //遍历JSON对象结束
      jsonReader.endObject();
    }
    //遍历数组结束
    jsonReader.endArray();
  } catch (IOException e) {
    e.printStackTrace();
  }
}

//先定义一个类
public class User {
  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;
  }
}
//只将一组数据转换的方法
findViewById(R.id.parseObj).setOnClickListener(new OnClickListener(){
  @Override
  public void onClick(View v) {
    String jsonData = "{\"name\":\"Michael\",\"age\":20}";
    Gson gson = new Gson();
    User user = gson.fromJson(jsonData, User.class);
    System.out.println("name--->" + user.getName());
    System.out.println("age---->" + user.getAge());
  }
});
//将多组数据转换的方法
findViewById(R.id.parseObjs).setOnClickListener(new OnClickListener(){
  @Override
  public void onClick(View v) {
    String jsonData = "[{\"name\":\"Michael\",\"age\":20},{\"name\":\"Mike\",\"age\":21}]";
    Type listType = new TypeToken<LinkedList<User>>(){}.getType();
    Gson gson = new Gson();
    LinkedList<User> users = gson.fromJson(jsonData, listType);
    for (Iterator iterator = users.iterator(); iterator.hasNext();) {
      User user = (User) iterator.next();
      System.out.println("name--->" + user.getName());
      System.out.println("age---->" + user.getAge());
    }
  }
});