Java之JSON处理（JSONObject、JSONArray）

依赖包：json-20180130.jar

MAVEN地址：

        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20180130</version>
        </dependency>

比较简单，一看就懂，源码如下：

package json;

import org.json.JSONArray;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

/**
 * JSONObject和JSONArray使用：进行JSON对象转换和操作
 * JSONObject：处理JSON串，多种构造方法，可用于多类型转账。
 * JSONArray：JSON数组，有顺序
 */
public class JsonFirst {
    public static void main(String[] args) {
        // 1、定义一个json对象
        JSONObject jo = new JSONObject();
        jo.put("id", "1");
        jo.put("name", "tom");
        jo.put("age", "25");
        System.out.println("1、JSONObject: " + jo);
        // 获取name值
        String name = jo.getString("name");
        System.out.println("查询name:" + name);

        // 2、定义一个Json数组，数组有顺序
        JSONArray ja = new JSONArray();
        ja.put(0, "yang");
        ja.put(1, "li");
        ja.put(2, "zhang");
        ja.put(4, "fouth");
        System.out.println("2、JSONArray数组: " + ja);
        // 获取第四个值
        String fouth = ja.getString(4);
        System.out.println("查询第四个：" + fouth);

        // 3、json中添加json对象组成复杂JSON
        jo.put("Object", ja);
        System.out.println("3、添加JSON对象后: " + jo);

        // 4、String转换为JSON（复杂JSON处理）
        String str = "{"name":"tom","Object":["yang","li","zhang",null,"fouth"],"id":"1","age":"25"}";
        JSONObject jo2 = new JSONObject(str);
        System.out.println("4、String转换为JSON:" + jo2);
        System.out.println("name属性值:" + jo2.getString("name"));
        System.out.println("Object属性值:" + jo2.get("Object").toString());
        // 删除Object属性值
        jo.remove("Object");
        System.out.println("删除Object属性值:" + jo);

        // 5、map和JSON转换
        Map<String, String> map1 = new HashMap<String, String>();
        map1.put("name", "Alexia");
        map1.put("sex", "female");
        map1.put("age", "23");
        JSONObject jo3 = new JSONObject(map1);
        System.out.println("5.1 map转JSON:" + jo3);
        Map<String, Object> map2 = new HashMap<String, Object>();
        map2 = jo3.toMap();
        System.out.println("5.2 JSON转map:" + map2);

        // 6、JSONArray中添加map和JSON对象
        JSONArray jo4 = new JSONArray();
        jo4.put(map1);
        jo4.put(1, "333");
        jo4.put(jo);
        System.out.println("6、JSONArray中添加map和JSON对象：" + jo4);

    }
}

运行结果：

1、JSONObject: {"name":"tom","id":"1","age":"25"}
查询name:tom
2、JSONArray数组: ["yang","li","zhang",null,"fouth"]
查询第四个：fouth
3、添加JSON对象后: {"name":"tom","Object":["yang","li","zhang",null,"fouth"],"id":"1","age":"25"}
4、String转换为JSON:{"name":"tom","Object":["yang","li","zhang",null,"fouth"],"id":"1","age":"25"}
name属性值:tom
Object属性值:["yang","li","zhang",null,"fouth"]
删除Object属性值:{"name":"tom","id":"1","age":"25"}
5.1 map转JSON:{"name":"Alexia","age":"23","sex":"female"}
5.2 JSON转map:{sex=female, name=Alexia, age=23}
6、JSONArray中添加map和JSON对象：[{"name":"Alexia","age":"23","sex":"female"},"333",{"name":"tom","id":"1","age":"25"}]