Gson解析

Android之Gson解析

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提示

JSON的解析-JSONObject和JSONArray 请看: http://blog.youkuaiyun.com/Peng_Hong_fu/article/details/52252986
使用Gson前,导入gson库和使用GsonFormat 请看: Android studio导入gson

Gson的使用是依附一个Bean对象

---

首先建立Person的一个Bean对象

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

    @Override
    public String toString() {
        return "Person{" +
                "age=" + age +
                ", name='" + name + '\'' +
                '}';
    }
    ........Setter and Getter......
}

Gson使用方法

json序列化

添加json数据,将bean里面的内容转换为json内容

• json序列化1

  /**
   *加入的数据是{"name":"peng","age":"19"}
   *一个对象
   */
    Person p =new Person();
    p.setName("peng");
    p.setAge(19);

    Gson gson =new Gson();
    System.out.println(gson.toJson(p));

---

• json序列化2

  /**
   *加入的数据是[{"name":"peng","age":"19"},
   *           {"name":"peng","age":"19"}]
   * 数组里包含两个对象
   */
    List<Person> list =new ArrayList<>();
    Person p =new Person();
    p.setName("peng");
    p.setAge(19);

    Person q =new Person();
    q.setName("jack");
    q.setAge(20);

    list.add(p);
    list.add(q);
    Gson gson =new Gson();
    System.out.println(gson.toJson(list));

---

• json序列化3

这次添加的是一个复杂的json数据,包括数组和对象的组合
这需要一个新的bean类
使用Android studio的GsonFormat 功能可以快速的生成以下的BaoBao类
具体方法在上方的提示给出

public class BaoBao {
    private String name;
    private String age;
    private List<OtherBean> other;

   ....Getter and Setter....

    public static class OtherBean {
        private String name;
        private String age;
        private String id;

        ....Getter and Setter....
    }
}

       /*添加的数据是 {"name":"宝强","age":"32",
                     "other":[{"name":"小马","age":"22","id":"1"},
                         {"name":"小蓉","age":"32","id":"2"},
                         {"name":"小王","age":"42","id":"3"}]}
        */
        BaoBao b =new BaoBao();
        b.setName("宝强");
        b.setAge("32");

        List<BaoBao.OtherBean> list =new ArrayList<>();
        /**
         * 如果你重写了OtherBean的构造函数
         * 你也可以这样加数据
         * BaoBao.OtherBean ob= new BaoBao.OtherBean("小马","22","1");
         */
        BaoBao.OtherBean ob= new BaoBao.OtherBean();
        ob.setName("小马");
        ob.setAge("22");
        ob.setId("1");

        BaoBao.OtherBean ob1= new BaoBao.OtherBean();
        ob1.setName("小荣");
        ob1.setAge("32");
        ob1.setId("2");

        BaoBao.OtherBean ob2= new BaoBao.OtherBean();
        ob2.setName("小王");
        ob2.setAge("42");
        ob2.setId("3");

        list.add(ob);
        list.add(ob1);
        list.add(ob2);

        b.setOther(list);

        Gson gson = new Gson();
        System.out.println(gson.toJson(b));

添加结果

json反序列化

json解析 ,从Json对象封装出一个一个的bean对象

• 解析1

 解析 {'name':'peng','age':'12'}

  String str = "{'name':'zhangsan','age':'12'}";
    Person person =new Person();
    Gson gson =new Gson();

    /*person =gson.fromJson("{name:'zhangsan'}",Person.class);*/
    person =gson.fromJson(str,Person.class);
    System.out.println(person.getName()+"  " + person.getAge());

解析结果

---

• 解析2

 二.解析 [{'name':'peng','age':'23'},{'name':'jack','age':'22'}]

String jsonData = "[{'name':'peng','age':'23'},{'name':'jack','age':'22'}]";
    Gson gson = new Gson();
    Type listType  = new TypeToken<List<Person>>(){}.getType();
    List<Person> list =gson.fromJson(jsonData ,listType);
    //use List or LinkList
    for(Person p:list) {
     System.out.println(p.getName()+" "+p.getAge());
     }
/**
*下面解析的方法和上面的方法有同样的效果
*/
   String jsonData = "[{\"name\":\"baoqiang\",\"age\":23},{\"name\":\"sunyang\",\"age\":34}]";
        Type listType = new TypeToken<LinkedList<Person>>(){}.getType();
        Gson gson = new Gson();
        LinkedList<Person> linklist = gson.fromJson(jsonData, listType);
        for (Iterator iterator = linklist.iterator(); iterator.hasNext();) {
            Person person = (Person) iterator.next();
            System.out.println(person.getName());
            System.out.println(person.getAge());
        }

解析结果

---

• 解析3
  这里解析一个复杂的json数据,包括数组和对象的组合

{"name":"宝强","age":"32",
"other":[{"name":"小马","age":"22","id":"1"},
   {"name":"小蓉","age":"32","id":"2"},
   {"name":"小王","age":"42","id":"3"}]
}

解析代码

            String str = "{\"name\":\"宝强\",\"age\":\"32\",\n" +
                    "\"other\":[{\"name\":\"小马\",\"age\":\"22\",\"id\":\"1\"},\n" +
                    "   {\"name\":\"小蓉\",\"age\":\"32\",\"id\":\"2\"},\n" +
                    "   {\"name\":\"小王\",\"age\":\"42\",\"id\":\"3\"}]\n" +
                    "}";
            Gson gson = new Gson();
            BaoBao js = gson.fromJson(str, BaoBao.class);
            System.out.println("name:" + js.getName() + " age:" + js.getAge());
            List<BaoBao.OtherBean> list = js.getOther();
            for (BaoBao.OtherBean ob : list){
                System.out.println("name:"+ob.getName() + " id:" + ob.getId() + " age:" + ob.getAge());
            }

2016年8月29号更新内容
直接通过GsonFormat生成的bean对象提取

Gson gson = new Gson();
BaoBao js = gson.fromJson(str, BaoBao.class);
//因为定义了bean对象,可以直接通过下面的方法提取,get(0)为第一个数组
System.out.println(js.getOther().get(0).getName()+js.getOther().get(0).getAge());
//取出的结果为 小马 22

解析结果

源码下载

GitHub地址:https://github.com/PengHongfu/Gson.git

参考

android Gson的使用 http://blog.youkuaiyun.com/kongzhichen/article/details/10135051
Android Gson解析json详解 http://www.open-open.com/lib/view/open1407376535942.html