使用Spring boot 创建RestFul服务
准备工作 1.JDK8
程序要实现的简单功能 当用户访问
http://localhost:8080/greeting
返回一个默认的Json字符串
{"id":1,"content":"Hello, World!"}
当用户访问
http://localhost:8080/greeting?name=User
返回 name后面的参数在后台组成的字符串
{"id":1,"content":"Hello, User!"}
创建Maven项目 创建一个普通的maven项目，添加maven依赖如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 <?xml version="1.0" encoding="UTF-8" ?> <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.zeusjava</groupId > <artifactId > SpringMVCRESTFul</artifactId > <version > 1.0-SNAPSHOT</version > <properties > <java.version > 1.8</java.version > </properties > <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 > </dependencies > <build > <plugins > <plugin > <groupId > org.springframework.boot</groupId > <artifactId > spring-boot-maven-plugin</artifactId > </plugin > </plugins > </build > <repositories > <repository > <id > spring-releases</id > <url > https://repo.spring.io/libs-release</url > </repository > </repositories > <pluginRepositories > <pluginRepository > <id > spring-releases</id > <url > https://repo.spring.io/libs-release</url > </pluginRepository > </pluginRepositories > </project >
各个包之间的依赖关系如下图：
创建一个User类，有id和name两个属性
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 package com.zeusjava;public class User { private final long id; private final String name; public User (long id, String name) { this .id = id; this .name = name; } public long getId () { return id; } public String getName () { return name; } }
当用户访问URL的时候，程序后台会自动获得URL上附带的名为name的参数。
创建一个resource controller 在Spring4中新增了一个@RestController注解，相当于Spring3中的@Controller和@ResponseBody两个注解一起的效果
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 package com.zeusjava;import java.util.concurrent.atomic.AtomicLong;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;@RestController public class UserController { private static final String template = "Hello, %s!" ; private final AtomicLong counter = new AtomicLong (); @RequestMapping("/greeting") public User greeting (@RequestParam(value="name", defaultValue="World") String name) { return new User (counter.incrementAndGet(), String.format(template, name)); } }
执行程序 main方法使用Spring Boot 的SpringApplication.run()来加载程序。
1 2 3 4 5 6 7 8 9 10 11 12 13 package com.zeusjava;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication public class Application { public static void main (String[] args) { SpringApplication.run(Application.class, args); } }
测试程序 在Application的main方法中运行application，在地址栏输入
http://localhost:8080/greeting
结果为：
再输入一次
http://localhost:8080/greeting?name=Zhaohongxuan
结果为：
不用配置繁琐的xml，一个简单的Restful风格的程序就创建好了。
