JSON简单快速入门

一.什么是JSON

JSON是一种与开发语言无关的，轻量级的数据格式。全称 JavaScript Object Notation

1.标准的JSON数据表示：

• 数据结构：

object
Array

• 基本类型：

String
number
true
false
null

2.Objext

使用花括号{ }包含的键值对结构，Key必须为String类型，value为任何基本类型或者数据结构。

3.array 和 value

4.String 和 number

二.如何通过JavaBean构建Json对象

百度云链接：http://pan.baidu.com/s/1eRK5IAe 密码：badq
提供了除JSONObject的jar之外依赖的其他6个jar包，一共7个jar文件

javaBeanJson.java

package com.huan.json;

/**
* Created by pc on 2017/5/8.
*/
public class javaBeanJson {
   private String name;
   private String school;
   private boolean hasGirlfriend;
   private double age ;
   private Object car;
   private Object house;
   private String [] major;
   private String comment;
   private String birthday;

   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 isHasGirlfriend() {
       return hasGirlfriend;
   }

   public void setHasGirlfriend(boolean hasGirlfriend) {
       this.hasGirlfriend = hasGirlfriend;
   }

   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 Object getHouse() {
       return house;
   }

   public void setHouse(Object house) {
       this.house = house;
   }

   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;
   }
}

jsonObject.java

package com.huan.json;

import net.sf.json.JSONObject;
import org.junit.Test;

/**
 * Created by pc on 2017/5/8.
 */
public class jsonObject {

    private static void createJsonBean(){
        javaBeanJson javabeanjson = new javaBeanJson();
        javabeanjson.setName("张飞");
        javabeanjson.setAge(25.0);
        javabeanjson.setBirthday("1999-09-29");
        javabeanjson.setSchool("西安交通大学");
        javabeanjson.setMajor(new String[]{"软件工程","通信工程"});
        javabeanjson.setHasGirlfriend(false);
        javabeanjson.setCar(null);
        javabeanjson.setHouse(null);
        JSONObject json =  JSONObject.fromBean(javabeanjson);

        System.out.println(json.toString());
    }

    public static void main(String[] args) {
        createJsonBean();
    }
}

打印输出：

json解析：

三.如何读取解析Json对象

导包commons-io-2.5-bin.zip下载：

链接：http://pan.baidu.com/s/1eRDKf8Q 密码：a7x0

从文件JsonFile.json中读取并解析Json

JsonFile.json

{
  "birthday": "1999-09-29",
  "major": [
    "软件工程",
    "通信工程"
  ],
  "car": null,
  "school": "西安交通大学",
  "hasGirlfriend": false,
  "name": "张飞",
  "comment": "",
  "house": null,
  "age": 25
}

ReadJsonSample.java

package com.huan.json;

import net.sf.json.JSON;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import org.apache.commons.io.FileUtils;

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

/**
 * Created by pc on 2017/5/8.
 */
public class ReadJsonSample {
    public static void main(String[] args) throws IOException {
        readJson();
    }
    public static void readJson() throws IOException {
        //读取JSON文件
        File file = new File(ReadJsonSample.class.getResource("/JsonFile.json").getFile());
            String content = FileUtils.readFileToString(file,"utf-8");
        JSONObject jsonObject = JSONObject.fromObject(content);
        System.out.println("name："+jsonObject.getString("name"));
        System.out.println("age："+jsonObject.getString("age"));
        System.out.println("comment："+jsonObject.getString("comment"));
        System.out.println("hasGirlfriend："+jsonObject.getString("hasGirlfriend"));
        System.out.println("school："+jsonObject.getString("school"));
        System.out.println("car："+jsonObject.getString("car"));
        System.out.println("birthday："+jsonObject.getString("birthday"));
        JSONArray major= jsonObject.getJSONArray("major");
        for(int i = 0; i<major.length();i++){
            String m = (String) major.get(1);
            System.out.println("专业-"+(i+1)+m);
        }
    }
}