JSONObject解析demo.json格式文件

利用JSONObject解析xxx.json格式文件

准备两个工具依赖
操作文件的io依赖jar包
JSONObject相关jar包

<dependencies>
  <!-- https://mvnrepository.com/artifact/org.json/json -->
  <!--json解析依赖-->
  <dependency>
      <groupId>org.json</groupId>
      <artifactId>json</artifactId>
      <version>20160810</version>
  </dependency>

  <!--引入io包,对文件进行解析-->
  <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
  </dependency>
</dependencies>

测试结构

pom.xml文件

test.json文件内容

{
  "hobbies": [
    "hiking",
    "swimming"
  ],
  "sex": "male",
  "name": "John",
  "is_student": true,
  "age": 22
}

代码测试片段

public class Exam01 {
    public static void main(String[] args) throws IOException {
        //准备file文件
        File file = new File("D:\\idea_work\\practise\\src\\main\\java\\test.json");
        //通过fileutils拿到文件的字符串
        String str = FileUtils.readFileToString(file);
        System.out.println(str);

        //对基本类型的解析
        JSONObject obj = new JSONObject(str);
        Object name = obj.get("name");
        System.out.println("name:"+name);
        System.out.println("---------------");
        Object hobbies = obj.get("hobbies");
        System.out.println("hobbies:"+hobbies);
    }
}

测试结果,先代码后分析

{
  "hobbies": [
    "hiking",
    "swimming"
  ],
  "sex": "male",
  "name": "John",
  "is_student": true,
  "age": 22
}

name:John
---------------
hobbies:["hiking","swimming"]

完整解析代码

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

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

public class Exam01 {
    public static void main(String[] args) throws IOException {
        //准备file文件
        File file = new File("D:\\idea_work\\practise\\src\\main\\java\\test.json");
        //通过fileutils拿到文件的字符串
        String str = FileUtils.readFileToString(file);

        //对基本类型的解析
        JSONObject obj = new JSONObject(str);
        //获取名字然后打印
        Object name = obj.get("name");
        System.out.println("name:"+name);
        //获取性别,然后打印
        Object sex = obj.get("sex");
        System.out.println("sex:"+sex);
        //获取是否是学生,然后打印
        Object is_student = obj.get("is_student");
        System.out.println("is_student:"+is_student);
        //获取年龄,然后打印
        Object age = obj.get("age");
        System.out.println("age:"+age);
        //获取数组,然后打印
        Object hobbies = obj.get("hobbies");
        System.out.println("hobbies数组:"+hobbies);

        //对数组进行解析,拿到里面的值
        JSONArray hobbiesArray = obj.getJSONArray("hobbies");

        //通过for循环遍历数组的内容
        for(int i=0;i<hobbiesArray.length();i++){
            String s = (String)hobbiesArray.get(i);
            System.out.println("hobbiesArray["+i+"]:"+s);
        }
    }
}

结果

name:John
sex:male
is_student:true
age:22
hobbies数组:["hiking","swimming"]
hobbiesArray[0]:hiking
hobbiesArray[1]:swimming

Process finished with exit code 0

解析xxx.json格式文件思路回顾

1.导入需要的工具类jar包JSONObject common-io

2.构建file文件,然后解析该文件

3.拿到json解析对象,调用get(“key”),obj.getJSONArray(“hobbies”)方法拿到对应的值,值的结果根据json文件可能为string字符串,或者数组

4.拿到字符串做其他操作
5.拿到数组进行操作,比如解析该数组,拿到索引对应的值

ok,tata!