//org.json.JSONArray;
//org.json.JSONObject;
private void parseJSONWithJSONObject(String jsonData){
try {
//将json字符串jsonData装入JSON数组，即JSONArray
//jsonData可以是从文件中读取，也可以从服务器端获得
JSONArray jsonArray = new JSONArray(jsonData);
for (int i = 0; i< jsonArray.length(); i++) {
//循环遍历，依次取出JSONObject对象
//用getInt和getString方法取出对应键值
JSONObject jsonObject = jsonArray.getJSONObject(i);
int stu_no = jsonObject.getInt("stu_no");
String stu_name = jsonObject.getString("stu_name");
String stu_sex = jsonObject.getString("stu_sex");
Log.d("MainActivity","stu_no: " + stu_no);
Log.d("MainActivity","stu_name: " + stu_name);
Log.d("MainActivity","stu_sex: " + stu_sex);
}
} catch (Exception e) {
e.printStackTrace();
}
}

[{ "stu_no":12345,"stu_name":"John","stu_sex":"male"
},{ "stu_no":12346,"stu_name":"Tom","stu_sex":"male"
},{"stu_no":12347,"stu_name":"Lily","stu_sex":"female"}]

public class Student {
private int stu_no;
private String stu_name;
private String stu_sex;
Student(int stu_no,String stu_name,String stu_sex){
this.stu_no = stu_no;
this.stu_name = stu_name;
this.stu_sex = stu_sex;
}
}
// 序列化，将Student对象stu转换为字符串str
Student stu = new Student(123,"Tom","male");
Gson gson = new Gson();
String str = gson.toJson(stu); 
//反序列化，将字符串转换为Student对象
jsonData = "{ "stu_no":12345,"stu_name":"John","stu_sex":"male" }";
Gson gson = new Gson();
Student student = gson.fromJson(jsonData,Student.class); 

Gson gson = new Gson();
int[] ints = {1, 2, 3, 4, 5};
String[] strings = {"abc", "def", "ghi"};
//序列化（serialization）
//将整数数组转换为JSON数组
gson.toJson(ints); // ==> [1,2,3,4,5]
//将字符串数组转换为JSON数组
gson.toJson(strings); // ==> ["abc", "def", "ghi"]
// 反序列化（Deserialization）
// 将JSON数组转换为原生类数组
// ints2、string2与ints、strings相等
int[] ints2 = gson.fromJson("[1,2,3,4,5]", int[].class); 
String[] strings2 = gson.fromJson("["abc", "def", "ghi"]",String[].class); 

//对于类似于2.2中的jsonData，包含3个Student对象
//与原生类不同，需要借助TypeToken获得期望解析成的数据类型
//下列代码运行后，students包含三个Student对象
Gson gson = new Gson();
List<Student> students;
students = gson.fromJson(jsonData, new TypeToken<List<Student>>(){}.getType()); // ==>[stu0,stu1,stu2]