springboot 返回JSON数据_springboot返回json对象

JSON是目前主流的前后端数据传输方式，Spring MVC中使用消息转换器HttpMessageConverter对JSON的转换提供了很好的支持，在Spring Boot中更进一步，对相关配置做了更进一步的简化。默认情况下，当开发者新创建一个Spring Boot项目后，添加Web依赖，代码如下：

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

这个依赖中默认加入了jackson-databind作为JSON处理器，此时不需要添加额外的JSON处理器就能返回一段JSON了。

新建一个springboot项目，具体截图

创建一个Book实体类：

Book.java

package com.shrimpking.code01;
 
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonIgnore;
 
import java.util.Date;
 
/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/6/4 11:02
 */
public class Book
{
    private String name;
    private String author;
    /**
     * 忽略此项
     */
    @JsonIgnore
    private Float price;
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date publicationDate;
 
    public Book()
    {
    }
 
    public Book(String name, String author, Float price, Date publicationDate)
    {
        this.name = name;
        this.author = author;
        this.price = price;
        this.publicationDate = publicationDate;
    }
 
    public String getName()
    {
        return name;
    }
 
    public void setName(String name)
    {
        this.name = name;
    }
 
    public String getAuthor()
    {
        return author;
    }
 
    public void setAuthor(String author)
    {
        this.author = author;
    }
 
    public Float getPrice()
    {
        return price;
    }
 
    public void setPrice(Float price)
    {
        this.price = price;
    }
 
    public Date getPublicationDate()
    {
        return publicationDate;
    }
 
    public void setPublicationDate(Date publicationDate)
    {
        this.publicationDate = publicationDate;
    }
 
    @Override
    public String toString()
    {
        return "Book{" + "name='" + name + '\'' + ", author='" + author + '\'' + ", price=" + price + ", publicationDate=" + publicationDate + '}';
    }
}

然后创建BookController，返回Book对象即可：

BookController.java

package com.shrimpking.code01;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
import java.util.Date;
 
/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/6/4 11:05
 */
@Controller
public class BookController
{
    @GetMapping("/book")
    @ResponseBody
    public Book test()
    {
        Book book = new Book();
        book.setAuthor("作者");
        book.setName("图书名");
        book.setPrice(999.00f);
        book.setPublicationDate(new Date());
        return book;
    }
}

------------------------------------------------------------------------------------------------------------------------------

 当然，如果需要频繁地用到@ResponseBody注解，那么可以采用@RestController组合注解代替@Controller和@ResponseBody，代码如下：

Book.java

package com.shrimpking.code02;
 
/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/6/4 11:11
 */
public class Book
{
    private String name;
    private String author;
 
    public String getName()
    {
        return name;
    }
 
    public void setName(String name)
    {
        this.name = name;
    }
 
    public String getAuthor()
    {
        return author;
    }
 
    public void setAuthor(String author)
    {
        this.author = author;
    }
 
    @Override
    public String toString()
    {
        return "Book{" + "name='" + name + '\'' + ", author='" + author + '\'' + '}';
    }
}

OtherController.java

package com.shrimpking.code02;
 
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
 
/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/6/4 11:11
 */
@RestController
/*
使用@RestController替代@Controller 和@ResponseBody
 */
public class OtherController
{
    @GetMapping("/otherbook")
    public Book test()
    {
        Book book = new Book();
        book.setName("什么书");
        book.setAuthor("哪个作者");
        return book;
    }
}