1.通过spring在线创建一个maven工程 地址：https://start.spring.io/
2.编写Controller 2.1GreetingController.java
package com.syh; import java.util.concurrent.atomic.AtomicLong; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; @Controller public class GreetingController { private static final String template = "Hello, %s!"; private final AtomicLong counter = new AtomicLong(); @RequestMapping("/greeting") public @ResponseBody Greeting greeting( @RequestParam(value="name", required=false, defaultValue="World") String name) { System.out.println("greeting"); return new Greeting(counter.incrementAndGet(), String.format(template, name)); } }2.2编写POJO类
Greeting .java
package com.syh; public class Greeting { private final long id; private final String content; public Greeting(long id, String content) { this.id = id; this.content = content; } public long getId() { return id; } public String getContent() { return content; } }2.3最终工程结构 3.运行 工程项目右键->RunAs->Spring Boot App 如遇到提示 “找不到或无法加载主类 com.syh.MavenGenarate2Application” 则在项目跟目录下运行已下命令： mvn compile mvn package mvn install 4.测试 http://localhost:8080/greeting?name=world 输出：
{ id: 3, content: "Hello, world!" }