gson在android中的应用

首先需要建一个实体类 Person.java 来对应json

需要注意的是实体类中的变量名必须和json传过来的key值完全一样（大小写）

public class Person {
    private String name;
    private int age;
    private String city;

    public Person(String name, int age, String city){
        this.name = name;
        this.age = age;
        this.city = city;
    }

    public Person(){}

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getAge() {
        return age;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCity() {
        return city;
    }
}

然后这是编码和解码的具体实现

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        List<Person> list = new ArrayList<Person>();
        Person person = new Person("Thh", 23, "CHENGDU");
        list.add(person);
        person = new Person("CBB", 22, "CHENGDU");
        list.add(person);
        person = new Person("CMT", 18, "TIANJIN");
        list.add(person);

        Gson gson = new Gson();

        Log.e("ABC", "" + gson.toJson(list));

        Person person1 = new Person();
        Gson gson1 = new Gson();

        String s=gson.toJson(list);
        Type lt=new TypeToken<List<Person>>(){}.getType();//获取一个泛型的数据类型
        List<Person> l=gson1.fromJson(s,lt);
        for(Person p1:l){
            Log.e("ABC",p1.getName() + " " + p1.getAge() + " " + p1.getCity());
        }
    }
}

Logcat中显示结果：

10-22 01:22:01.444 16669-16669/? E/ABC: [{"age":23,"city":"CHENGDU","name":"Thh"},{"age":22,"city":"CHENGDU","name":"CBB"},{"age":18,"city":"TIANJIN","name":"CMT"}]
10-22 01:22:01.448 16669-16669/? E/ABC: Thh 23 CHENGDU
10-22 01:22:01.448 16669-16669/? E/ABC: CBB 22 CHENGDU
10-22 01:22:01.449 16669-16669/? E/ABC: CMT 18 TIANJIN