springBoot 学习记录(二)-返回json数据的几种方式

一：新建maven项目

pom.xml 代码：

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.phpfzh2</groupId>

  <artifactId>spring-boot01</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <packaging>war</packaging>

  

  <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.0.RELEASE</version>
</parent>

  

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

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>fastjson</artifactId>
   <version>1.2.20</version>
</dependency>

</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

启动类App代码：

package com.phpfzh;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class ApplicationTest {

public static void main(String[] args) {
SpringApplication.run(ApplicationTest.class, args);
}

}

实体类代码：

package com.phpfzh.mode;

import java.math.BigDecimal;

public class User {

private BigDecimal id;
private String username;
private String sex;

public BigDecimal getId() {
return id;
}

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

public String getUsername() {
return username;
}

public void setUsername(String username) {
this.username = username;
}

public String getSex() {
return sex;
}

public void setSex(String sex) {
this.sex = sex;
}

 }

第一种方式@RestController：

package com.phpfzh.web;

import java.math.BigDecimal;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import com.phpfzh.mode.User;

@RestController

public class TestController {

@RequestMapping("/")

  public User test(){
User user = new User();
user.setId(new BigDecimal(12));
user.setSex("12");
user.setUsername("phpfzh");
return user;
}

}

运行项目：

右击项目 点击 run As   ==> Maven clear    ====> maven install  

 右击项目 点击 run As ===>
java application ===》 在浏览器输入：localhost：8080/ 

输出：

{"id":12,"username":"phpfzh","sex":"12"}

第二种方式@ResponseBody：

package com.phpfzh.web;

import java.math.BigDecimal;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.ResponseBody;

import com.phpfzh.mode.User;

@Controller

public class TestController2 {

@ResponseBody
@RequestMapping("/test2")
public User test2(){
User user = new User();
user.setId(new BigDecimal(12));
user.setSex("12");
user.setUsername("phpfzh-test2");
return user;
}

}

运行项目：

右击项目 点击 run As   ==> Maven clear    ====> maven install  

 右击项目 点击 run As ===> java application ===》 在浏览器输入：localhost：8080/test2 

浏览器输出：

{"id":12,"username":"phpfzh-test2","sex":"12"}

第三种方式response：

在pom.xml 添加 阿里巴巴json jar包：

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>fastjson</artifactId>
   <version>1.2.20</version>
</dependency>

Controller代码：

package com.phpfzh.web;

import java.io.PrintWriter;

import java.math.BigDecimal;

import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import com.alibaba.fastjson.JSON;

import com.phpfzh.mode.User;

@Controller

public class TestController3 {

@RequestMapping("/test3")

  public String test(HttpServletResponse response){
User user = new User();
user.setId(new BigDecimal(12));
user.setSex("12");
user.setUsername("phpfzh-test3");
String date = JSON.toJSONString(user);
try {
sendJsonData(response, date);
} catch (Exception e) {

  e.printStackTrace();
}
return null;
}

protected void sendJsonData(HttpServletResponse response, String data)
throws Exception
{
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.println(data);
out.flush();
out.close();
}

}

运行项目：

右击项目 点击 run As   ==> Maven clear    ====> maven install  

 右击项目 点击 run As ===> java application ===》 在浏览器输入：localhost：8080/test3 

浏览器输出：

{"id":12,"sex":"12","username":"phpfzh-test3"}