JSON

1、简介

JSON : JavaScript Object Notation

2、对象格式

一本书
	书名
	作者
	出版社

2.1、java

//java
public class Book{
    private String name;
    private String writer;
    private String publisher;
}

Book book = new Book();
book.setName("我是书名")；
book.setWriter("我是作者")；
book.setPublisher("我是出版社")；

2.2 、javascript

//javascript
var book = new Object();
book.name = "我是书名";
book.writer = "我是作者";
book.publisher = "我是出版社";

2.3、XML

<books>
    <book>
        <name>"我是书名"</name>
        <writer>"我是作者"</writer>
        <publisher>"我是出版社"</publisher>
    </book>
</books>

2.4、JSON

{
    "name":"我是书名",
    "writer" : "我是作者",
	"publisher" : "我是出版社"
}

3、Java与JSON

3.1、Java与JSON能做什么

• 将java中的对象转换成JSON格式的字符串
• 将JSON的字符串转换成为Java对象

3.2、Gson

• 将java中的对象转换成JSON格式的字符串

import com.google.gson.Gson;
public class GaonJava2Json {
    public static void main(String[] args) {

        Book book = new Book("我是书","我是作者","我是出版社");
        Gson gson = new Gson();
        String bookJson = gson.toJson(book);
        System.out.println(bookJson);
        //{"name":"我是书","writer":"我是作者","publisher":"我是出版社"}
    }
}

• 将JSON的字符串转换成为Java对象

import com.google.gson.Gson;

public class GsonJson2Java {

    public static void main(String[] args) {

        String str =
                "{\"name\":\"我是书\",\"writer\":\"我是作者\",\"publisher\":\"我是出版社\"}";
        Gson gson = new Gson();
        Book book = gson.fromJson(str, Book.class);
        System.out.println(book);
        //Book{name='我是书', writer='我是作者', publisher='我是出版社'}
    }
}

3.3、FastJson

• 将java中的对象转换成JSON格式的字符串

import com.alibaba.fastjson.JSON;

public class FastJsonJava2Json {

    public static void main(String[] args) {

        Book book = new Book("我是书","我是作者","我是出版社");
        String jsonString = JSON.toJSONString(book);
        
        System.out.println(jsonString);
        //{"name":"我是书","publisher":"我是出版社","writer":"我是作者"}
    }   
}

• 将JSON的字符串转换成为Java对象

import com.alibaba.fastjson.JSON;


public class FastJsonJson2Java {

    public static void main(String[] args) {

        String str =
                "{\"name\":\"我是书\",\"writer\":\"我是作者\",\"publisher\":\"我是出版社\"}";

        Book book = JSON.parseObject(str, Book.class);
        System.out.println(book);
        //Book{name='我是书', writer='我是作者', publisher='我是出版社'}
    }
}