json---简单入门

1.推荐使用第三种方式JAVABEAN的方式（使用前引入org.json）

package day05;

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

import org.json.JSONException;
import org.json.JSONObject;

import Bean.Diaosi;
public class JsonObjectSample {
    public static void main(String[] args) {
        JSONObject1();
        //createJsonByBean();
        //createJsonByMap();
    }

    private static void JSONObject1() {
        // TODO Auto-generated method stub
        JSONObject wangxiaoer=new JSONObject();
        Object nullObject=null;
        try {
            wangxiaoer.put("name", "wangxiaoer");
            wangxiaoer.put("age",25.2);
            wangxiaoer.put("birthday", "1990-01-01");
            wangxiaoer.put("school", "蓝翔");
            wangxiaoer.put("major", new String[]{"理发","挖掘机"});
            wangxiaoer.put("has_girlfriend",false);
            wangxiaoer.put("car", nullObject);
            wangxiaoer.put("comment", "这是一个注释");
            System.out.println(wangxiaoer.toString());
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    //MAP的方式
    private static void createJsonByMap(){
        Map<String,Object> wangxiaoer=new HashMap<String,Object>();
        Object nullObject=null;
        wangxiaoer.put("name", "wangxiaoer");
        wangxiaoer.put("age",25.2);
        wangxiaoer.put("birthday", "1990-01-01");
        wangxiaoer.put("school", "蓝翔");
        wangxiaoer.put("major", new String[]{"理发","挖掘机"});
        wangxiaoer.put("has_girlfriend",false);
        wangxiaoer.put("car", nullObject);
        wangxiaoer.put("comment", "这是一个注释");
        System.out.println(new JSONObject(wangxiaoer).toString());
    }
    //JAVABEAN的方式

    private static void createJsonByBean(){
        Diaosi wangxiaoer=new Diaosi();
        Object nullObject=null;
        wangxiaoer.setName("wangxiaoer");
        wangxiaoer.setAge(25.2);
        wangxiaoer.setBirthday("1990-01-01");
        wangxiaoer.setSchool("蓝翔");
        wangxiaoer.setMajor(new String[]{"理发","挖掘机"});
        wangxiaoer.setHas_girlfriend(false);
        wangxiaoer.setCar(nullObject);
        wangxiaoer.setComment("这是一个注释");
        System.out.println(new JSONObject(wangxiaoer));
    }
}

bean

package Bean;

public class Diaosi {
    private String name;
    private String school;
    private boolean has_girlfriend;
    private double age;
    private Object car;
    private String[] major;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSchool() {
        return school;
    }
    public void setSchool(String school) {
        this.school = school;
    }
    public boolean isHas_girlfriend() {
        return has_girlfriend;
    }
    public void setHas_girlfriend(boolean has_girlfriend) {
        this.has_girlfriend = has_girlfriend;
    }
    public double getAge() {
        return age;
    }
    public void setAge(double age) {
        this.age = age;
    }
    public Object getCar() {
        return car;
    }
    public void setCar(Object car) {
        this.car = car;
    }
    public String[] getMajor() {
        return major;
    }
    public void setMajor(String[] major) {
        this.major = major;
    }
    public String getComment() {
        return comment;
    }
    public void setComment(String comment) {
        this.comment = comment;
    }
    public String getBirthday() {
        return birthday;
    }
    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }
    private String comment;
    private String birthday;

}

2.解析json

wangxiaoer.json

{
"car":null,
"birthday": "1990-01-01",
"school":"蓝翔",
"has_girlfrend":false,
"age":25.2,
"name":"王小二",
"comment":"这是一个注释",
"major":["理发","挖掘机"]

}

readjsonsample.java

package day05;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class ReadJSONSample {
    public static void main(String[] args) throws IOException, JSONException {
        File file = new File(ReadJSONSample.class.getResource("/wangxiaoer.json").getFile());
        String content = FileUtils.readFileToString(file);
        JSONObject jsonObject = new JSONObject(content);
        if (!jsonObject.isNull("name")) {
            System.out.println("姓名 ：" + jsonObject.getString("name"));
        }
        System.out.println("年龄 ：" + jsonObject.getDouble("age"));
        System.out.println("有没有女朋友 ：" + jsonObject.getBoolean("has_girlfrend"));
        JSONArray list = jsonObject.getJSONArray("major");
        for (int i = 0; i < list.length(); i++) {
            String m = (String) list.get(i);
            System.out.println("专业-" + (i + 1) + m);
        }
    }

}

结果：

姓名 ：王小二

年龄 ：25.2

有没有女朋友 ：false

专业-1理发

专业-2挖掘机