springmvc返回json数据-蒲公英云

springmvc返回json数据

港控/mmm° 2022-06-01 08:20 356阅读 0赞

先去http://mvnrepository.com/搜索fastjson，jackson-annotations，jackson-databind，jackson-core这几个库，根据对应的版本号拿到pom.xml中dependency标签内容，然后复制到项目中的pom.xml中

项目的pom.xml如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.springdemo</groupId>
  <artifactId>demo</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>demo Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.2.4.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.0</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.0</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.9.0</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.41</version>
    </dependency>
  </dependencies>
  <build>
    <finalName>demo</finalName>
  </build>
  <properties>  
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
  </properties>  
</project>

然后项目maven install下载库

编写controller，使用@Responsebody注解，指定返回内容

使用了@ResponseBody能够直接将controller返回的bean对象或map对象等自动进行json或xml格式的转换，无需再使用JSONObject或者
response.setContentType（”application/json”）+PrintWriter来将返回的bean、String、map对象转换成JSON格式，再输出到页面上

代码，World.java:

package com.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class World {
    @RequestMapping(value="/hworld",method = RequestMethod.GET)
    public @ResponseBody
    String sayHello(){
        return "{\"returncode\":0,\"message\":\"hello world\"}";
    }
}