5分钟构建基于Spring Web MVC REST风格HelloWorld示例

当然写本文的目的不是为了速度，只是表明现在构建一个Spring web mvc Rest风格的HelloWorld应用会很简单。不过如果看过Spring Boot这个项目，可能只需要最多3分钟就能构建一个简单的Rest风格应用。回头研究下，然后分享下。

我的构建环境

JDK 7

Maven 3

Servlet3容器

创建项目

首先使用Maven创建一个普通Maven应用即可，不必是web的。

添加依赖

        <!-- servlet 3 -->          <dependency>              <groupId>javax.servlet</groupId>              <artifactId>javax.servlet-api</artifactId>              <version>3.0.1</version>          </dependency>            <!--spring context -->          <dependency>              <groupId>org.springframework</groupId>              <artifactId>spring-context-support</artifactId>              <version>4.0.0.RELEASE</version>          </dependency>            <!--spring webmvc -->          <dependency>              <groupId>org.springframework</groupId>              <artifactId>spring-webmvc</artifactId>              <version>4.0.0.RELEASE</version>          </dependency>            <!--jackson -->          <dependency>              <groupId>com.fasterxml.jackson.core</groupId>              <artifactId>jackson-databind</artifactId>              <version>2.2.3</version>          </dependency>

 servlet3依赖scope是provided表示环境提供，然后添加spring-context-support和spring-webmvc依赖，最后用于json的jackson依赖。非常简单明了。

添加maven插件

为了方便测试，添加jetty的maven插件，这样直接使用mvn jetty:run即可运行。

    <build>          <finalName>springmvc</finalName>          <plugins>              <plugin>                  <groupId>org.mortbay.jetty</groupId>                  <artifactId>jetty-maven-plugin</artifactId>                  <version>8.1.8.v20121106</version>                  <configuration>                      <reload>manual</reload>                      <webAppConfig>                          <contextPath>/${project.build.finalName}</contextPath>                      </webAppConfig>                      <connectors>                          <connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector">                              <port>9080</port>                              <!--<maxIdleTime>60000</maxIdleTime>-->                          </connector>                      </connectors>                  </configuration>              </plugin>          </plugins>      </build>

实体 

package com.sishuok.entity;    import java.io.Serializable;    /**   * <p>User: Zhang Kaitao   * <p>Date: 13-12-19   * <p>Version: 1.0   */  public class User implements Serializable {      private Long id;      private String name;        public Long getId() {          return id;      }        public void setId(Long id) {          this.id = id;      }        public String getName() {          return name;      }        public void setName(String name) {          this.name = name;      }        @Override      public boolean equals(Object o) {          if (this == o) return true;          if (o == null || getClass() != o.getClass()) return false;            User user = (User) o;            if (id != null ? !id.equals(user.id) : user.id != null) return false;            return true;      }        @Override      public int hashCode() {          return id != null ? id.hashCode() : 0;      }  }

控制器

package com.sishuok.controller;    import com.sishuok.entity.User;  import org.springframework.web.bind.annotation.PathVariable;  import org.springframework.web.bind.annotation.RequestMapping;  import org.springframework.web.bind.annotation.RequestMethod;  import org.springframework.web.bind.annotation.RestController;    /**   * <p>User: Zhang Kaitao   * <p>Date: 13-12-19   * <p>Version: 1.0   */  @RestController  @RequestMapping("/user")  public class UserController {        @RequestMapping(value = "/{id}", method = RequestMethod.GET)      public User view(@PathVariable("id") Long id) {          User user = new User();          user.setId(id);          user.setName("zhang");          return user;      }  }

SpringMVC注解风格配置

@Configuration  @EnableWebMvc  @ComponentScan  public class AppConfig {  }

Servlet3容器启动初始化器

在Servlet容器启动时编程式注册Servlet

package com.sishuok;    import org.springframework.web.WebApplicationInitializer;  import org.springframework.web.context.WebApplicationContext;  import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;  import org.springframework.web.servlet.DispatcherServlet;    import javax.servlet.ServletContext;  import javax.servlet.ServletException;  import javax.servlet.ServletRegistration;    /**   * <p>User: Zhang Kaitao   * <p>Date: 13-12-19   * <p>Version: 1.0   */  public class AppInitializer implements WebApplicationInitializer {        @Override      public void onStartup(ServletContext servletContext) throws ServletException {          AnnotationConfigWebApplicationContext webApplicationContext =                  new AnnotationConfigWebApplicationContext();          webApplicationContext.register(AppConfig.class);              DispatcherServlet dispatcherServlet = new DispatcherServlet(webApplicationContext);          ServletRegistration.Dynamic dynamic = servletContext.addServlet("dispatcherServlet", dispatcherServlet);          dynamic.addMapping("/");        }  }

然后运行 mvn jetty:run运行即可，浏览器输入如下地址即可得到我们的json数据。

http://localhost:9080/springmvc/user/1

参考示例的github地址：springmvc-rest-helloworld

非常简单的一个Rest风格的web应用就搭建完了，接下来再完善即可。