Springmvc 简明教程

Spring MVC - Hello World Example

以下示例展示了如何使用 Spring MVC 框架编写简单基于 web 的 Hello World 应用程序。首先，我们准备一个可用的 Eclipse IDE，然后遵循以下步骤使用 Spring Web 框架开发一个动态 Web 应用程序。

The following example shows how to write a simple web based Hello World application using the Spring MVC Framework. To start with, let us have a working Eclipse IDE in place and follow the subsequent steps to develop a Dynamic Web Application using the Spring Web Framework.

Step	Description
1	Create a Dynamic Web Project with a name HelloWeb and create a package com.tutorialspoint under the src folder in the created project.
2	Drag and drop the following Spring and other libraries into the folder WebContent/WEB-INF/lib..
3	Create a Java class HelloController under the com.tutorialspoint package.
4	Create Spring configuration files web.xml and HelloWeb-servlet.xml under the WebContent/WEB-INF folder.
5	Create a sub-folder with a name jsp under the WebContent/WEB-INFfolder. Create a view file hello.jsp under this sub-folder.
6	The final step is to create the content of the source and configuration files and export the application as explained below.

HelloController.java

package com.tutorialspoint;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.ui.ModelMap;

@Controller
@RequestMapping("/hello")
public class HelloController{

   @RequestMapping(method = RequestMethod.GET)
   public String printHello(ModelMap model) {
      model.addAttribute("message", "Hello Spring MVC Framework!");

      return "hello";
   }

}

web.xml

<web-app id = "WebApp_ID" version = "2.4"
   xmlns = "http://java.sun.com/xml/ns/j2ee"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://java.sun.com/xml/ns/j2ee
   http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

   <display-name>Spring MVC Application</display-name>

   <servlet>
      <servlet-name>HelloWeb</servlet-name>
      <servlet-class>
         org.springframework.web.servlet.DispatcherServlet
      </servlet-class>
      <load-on-startup>1</load-on-startup>
   </servlet>

   <servlet-mapping>
      <servlet-name>HelloWeb</servlet-name>
      <url-pattern>/</url-pattern>
   </servlet-mapping>

</web-app>

HelloWeb-servlet.xml

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:context = "http://www.springframework.org/schema/context"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "
   http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">

   <context:component-scan base-package = "com.tutorialspoint" />

   <bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name = "prefix" value = "/WEB-INF/jsp/" />
      <property name = "suffix" value = ".jsp" />
   </bean>

</beans>

hello.jsp

<%@ page contentType = "text/html; charset = UTF-8" %>
<html>
   <head>
      <title>Hello World</title>
   </head>
   <body>
      <h2>${message}</h2>
   </body>
</html>

以下是包含在 Web 应用程序中的 Spring 及其他库的列表。我们可以直接将这些文件拖放到 WebContent/WEB-INF/lib 文件夹中。

Following is the list of Spring and other libraries to be included in the web application. We can just drag these files and drop them in – WebContent/WEB-INF/lib folder.

servlet-api-x.y.z.jar
commons-logging-x.y.z.jar
spring-aop-x.y.z.jar
spring-beans-x.y.z.jar
spring-context-x.y.z.jar
spring-core-x.y.z.jar
spring-expression-x.y.z.jar
spring-webmvc-x.y.z.jar
spring-web-x.y.z.jar

完成后创建源代码和配置文件，导出你的应用程序。右键单击你的应用程序，使用 Export → WAR File 选项并保存 HelloWeb.war 文件到 Tomcat 的 webapps 文件夹中。

Once you are done with creating source and configuration files, export your application. Right click on your application, use Export → WAR File option and save your HelloWeb.war file in Tomcat’s webapps folder.

现在，启动 Tomcat 服务器并确保你可以使用标准浏览器访问 webapps 文件夹中的其他网页。然后，尝试访问 URL − http://localhost:8080/HelloWeb/hello 。如果 Spring Web 应用程序一切正常，我们将看到以下屏幕。

Now start your Tomcat server and make sure you are able to access other webpages from webapps folder using a standard browser. Now, try to access the URL − http://localhost:8080/HelloWeb/hello. If everything is fine with the Spring Web Application, we will see the following screen.

你应该注意，在给定的 URL 中， HelloWeb 是应用程序名称，hello 是虚拟子文件夹，我们使用 @RequestMapping("/hello") 在控制器中已经提到了该文件夹。你可以使用 @RequestMapping("/") 将你的 URL 直接映射到根目录，在这种情况下，你可以使用缩写 URL http://localhost:8080/HelloWeb/ 访问同一个页面，但建议在不同的文件夹下有不同的功能。

You should note that in the given URL, HelloWeb is the application name and hello is the virtual subfolder, which we have mentioned in our controller using @RequestMapping("/hello"). You can use direct root while mapping your URL using @RequestMapping("/"), in this case you can access the same page using short URL http://localhost:8080/HelloWeb/, but it is advised to have different functionalities under different folders.