SpringMVC实现Restful风格的WebService

1.环境

• JDK7
• MyEclipse2014
• tomcat8
• maven 3.3.3
• spring4.1.4

2.创建maven工程

3.指定依赖文件

 1 <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">
 2   <modelVersion>4.0.0</modelVersion>
 3   <groupId>com.dy.xidian</groupId>
 4   <artifactId>transport</artifactId>
 5   <version>0.0.1-SNAPSHOT</version>
 6   <packaging>war</packaging>
 7   <name>transport Maven Webapp</name>
 8   <url>http://maven.apache.org</url>
 9
10   <properties>
11     <spring.version>4.1.4.RELEASE</spring.version>
12   </properties>
13
14   <dependencies>
15       <dependency>
16          <groupId>junit</groupId>
17       <artifactId>junit</artifactId>
18       <version>3.8.1</version>
19       <scope>test</scope>
20     </dependency>
21     <dependency>
22         <groupId>org.springframework</groupId>
23         <artifactId>spring-core</artifactId>
24         <version>${spring.version}</version>
25     </dependency>
26     <dependency>
27       <groupId>org.springframework</groupId>
28       <artifactId>spring-context</artifactId>
29       <version>${spring.version}</version>
30     </dependency>
31     <dependency>
32       <groupId>org.springframework</groupId>
33       <artifactId>spring-webmvc</artifactId>
34       <version>${spring.version}</version>
35     </dependency>
36     <!-- web项目编译时需要，部署到tomcat中就不需要了 -->
37     <dependency>
38       <groupId>javax.servlet</groupId>
39       <artifactId>servlet-api</artifactId>
40       <version>2.5</version>
41       <scope>provided</scope>
42     </dependency>
43     <dependency>
44     <groupId>javax.servlet.jsp</groupId>
45       <artifactId>jsp-api</artifactId>
46       <version>2.2</version>
47     <scope>provided</scope>
48     </dependency>
49
50     <dependency>
51          <groupId>com.fasterxml.jackson.core</groupId>
52       <artifactId>jackson-databind</artifactId>
53       <version>2.3.4</version>
54     </dependency>
55     <dependency>
56       <groupId>com.fasterxml.jackson.core</groupId>
57        <artifactId>jackson-annotations</artifactId>
58       <version>2.4.0</version>
59     </dependency>
60     <dependency>
61       <groupId>com.fasterxml.jackson.core</groupId>
62       <artifactId>jackson-core</artifactId>
63       <version>2.4.3</version>
64     </dependency>
65   </dependencies>
66
67   <build>
68     <finalName>transport</finalName>
69   </build>
70 </project>

4.配置web.xml

 1 <!DOCTYPE web-app PUBLIC
 2  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 3  "http://java.sun.com/dtd/web-app_2_3.dtd" >
 4
 5 <web-app>
 6   <display-name>Archetype Created Web Application</display-name>
 7
 8   <context-param>
 9        <param-name>contextConfigLocation</param-name>
10      <param-value>/WEB-INF/transport-servlet.xml</param-value>
11   </context-param>
12   <servlet>
13         <servlet-name>transport</servlet-name>
14         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
15         <load-on-startup>1</load-on-startup>
16     </servlet>
17    <servlet-mapping>
18        <servlet-name>transport</servlet-name>
19        <url-pattern>/</url-pattern>
20     </servlet-mapping>
21   <listener>
22       <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
23   </listener>
24 </web-app>

5.配置spring的配置文件(spring-servlet.xml)

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:mvc="http://www.springframework.org/schema/mvc"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans
 7         http://www.springframework.org/schema/beans/spring-beans.xsd
 8         http://www.springframework.org/schema/context
 9         http://www.springframework.org/schema/context/spring-context-4.1.xsd
10         http://www.springframework.org/schema/mvc
11          http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
12
13     <mvc:annotation-driven />
14     <context:component-scan base-package="com.dy.xidian" />
15 </beans>

6.controller的实现

6.1建立bean类

　　在开始的图片中，我们可以看到有个Greeting.java类，它其实就是一个bean类，具体代码如下。

 1 package com.dy.xidian;
 2
 3 public class Greeting {
 4     private final long id;
 5     private final String content;
 6
 7     public Greeting(long id, String content) {
 8         this.id = id;
 9         this.content = content;
10     }
11
12     public long getId() {
13         return id;
14     }
15
16     public String getContent() {
17         return content;
18     }
19 }

6.2 在控制器中处理请求

　　SpringMVC会将请求交给一个控制器来处理，所以我们必须实现这样一个控制器，不过这个控制器在编写时要遵循restful风格。

　　GreetingController.java

 1 package com.dy.xidian;
 2
 3 import java.util.concurrent.atomic.AtomicLong;
 4
 5 import org.springframework.web.bind.annotation.RequestMapping;
 6 import org.springframework.web.bind.annotation.RequestParam;
 7 import org.springframework.web.bind.annotation.RestController;
 8
 9 @RestController
10 public class GreetingController {
11     private static final String template = "Hello, %s!";
12     private final AtomicLong counter = new AtomicLong();
13
14     @RequestMapping("/getuser")
15     public Greeting greeting(
16             @RequestParam(value = "name", defaultValue = "World") String name) {
17         return new Greeting(counter.incrementAndGet(), String.format(template,
18                 name));
19     }
20 }

虽然控制器返回的是一个Greeting对象，但是Spring会通过Jackson工具将其转换为一个json串。

7.访问

8.参考文章