Java日常开发小结-01

一、fastjson2

FastJson对于json格式字符串的解析主要用到三个类
1.JSON：解析器，用于JSON格式字符串与JSON对象及javaBean之间的转换 
2.JSONObject：json对象 
3.JSONArray：  json数组对象

1.1、引入依赖

<dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>fastjson</artifactId>
  <version>1.2.76</version>
</dependency>

1.2、使用

import java.math.BigDecimal;

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONArray;
import com.alibaba.fastjson2.JSONB;
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.annotation.JSONField;

public class Book {

    private Long id;
    @JSONField(name = "name")
    private String name ;

    private BigDecimal price;


    public Book() {
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", price=" + price +
                '}';
    }


    public static void main(String[]args) {
        Book book = new Book();
        book.setId(90L);
        book.setName("Success of mindset");
        book.setPrice(new BigDecimal(88.8));

        // 序列化
        System.out.println("---JSON.toJSONString: "+JSON.toJSONString(book));
        System.out.println("---JSONArray.toJSONString: "+JSONArray.toJSONString(book));
        byte[] bytes = JSONB.toBytes(book);
        System.out.println();
        System.out.println();

        // 反序列化
        String str ="{\"id\": 11,\"name\": \"fastjson2\",\"price\": \"88.8\"}";
        System.out.println("---JSON.parseObject: "+(Book)JSON.parseObject(str,Book.class));
        JSONObject jsonObject = JSON.parseObject(str);
        System.out.println("---jsonObject: "+jsonObject);
        System.out.println("------jsonObject.getIntValue:"+jsonObject.getIntValue("id"));
        System.out.println("---JSONB.parseObject: "+JSONB.parseObject(bytes,Book.class));
        System.out.println();
        System.out.println();

        // JSON解析为JSONObject
        String text = "{\"id\": 11,\"name\": \"fastjson2\",\"price\": \"99.8\"}";
        System.out.println("---JSON.parseObject: "+JSON.parseObject(text));

    }

}

/*
---JSON.toJSONString: {"id":90,"name":"Success of mindset","price":88.7999999999999971578290569595992565155029296875}
---JSONArray.toJSONString: {"id":90,"name":"Success of mindset","price":88.7999999999999971578290569595992565155029296875}


---JSON.parseObject: Book{id=11, name='fastjson2', price=88.8}
---jsonObject: {"id":11,"name":"fastjson2","price":"88.8"}
------jsonObject.getIntValue:11
---JSONB.parseObject: Book{id=90, name='Success of mindset', price=88.7999999999999971578290569595992565155029296875}


---JSON.parseObject: {"id":11,"name":"fastjson2","price":"99.8"}
*/

二、String 的使用

2.1、

2.2、

2.3、

三、