http://www.mkyong.com/maven/how-to-create-a-web-application-project-with-maven/

不念不忘少年蓝@ 2022-08-13 12:39 250阅读 0赞



In this tutorial, we will show you how to use Maven to create a Java web application (with Spring MVC) project, and make it support Eclipse IDE.

Tools used :

  1. Maven 3.0.5
  2. Eclipse 4.2
  3. JDK 6
  4. Spring 3.2.0.RELEASED
  5. Tomcat 7

1. Web Application Project from Maven Template

In a terminal (*uix or Mac) or command prompt (Windows), navigate to the folder you want to store the project. Issue following command :

  1. mvn archetype:generate -DgroupId={ project-packaging} -DartifactId={ project-name} -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false

This tell Maven to create a Java web application project from “maven-archetype-webapp” template.

For example,

  1. $ pwd
  2. /Users/mkyong/Documents/workspace
  4. $ mvn archetype:generate -DgroupId=com.mkyong -DartifactId=CounterWebApp -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false
  5. [INFO] Scanning for projects...
  6. [INFO]                                                                         
  7. [INFO] ------------------------------------------------------------------------
  8. [INFO] Building Maven Stub Project (No POM) 1
  9. [INFO] ------------------------------------------------------------------------
  10. [INFO] 
  11. [INFO] Generating project in Batch mode
  12. [INFO] ----------------------------------------------------------------------------
  13. [INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-webapp:1.0
  14. [INFO] ----------------------------------------------------------------------------
  15. [INFO] Parameter: groupId, Value: com.mkyong
  16. [INFO] Parameter: packageName, Value: com.mkyong
  17. [INFO] Parameter: package, Value: com.mkyong
  18. [INFO] Parameter: artifactId, Value: CounterWebApp
  19. [INFO] Parameter: basedir, Value: /Users/mkyong/Documents/workspace
  20. [INFO] Parameter: version, Value: 1.0-SNAPSHOT
  21. [INFO] project created from Old (1.x) Archetype in dir: /Users/mkyong/Documents/workspace/CounterWebApp
  22. [INFO] ------------------------------------------------------------------------
  23. [INFO] BUILD SUCCESS
  24. [INFO] ------------------------------------------------------------------------
  25. [INFO] Total time: 3.147s
  26. [INFO] Finished at: Thu Dec 20 20:35:19 MYT 2012
  27. [INFO] Final Memory: 12M/128M
  28. [INFO] ------------------------------------------------------------------------

In above case, a new web application project named “CounterWebApp“, and the entire project directory structure is created automatically.

2. Maven Directory Layout

Maven created following web application directory layout. A standard deployment descriptorweb.xml and Maven pom.xml are created.

  1. CounterWebApp
  2.    |-src
  3.    |---main
  4.    |-----resources
  5.    |-----webapp
  6.    |-------index.jsp
  7.    |-------WEB-INF
  8.    |---------web.xml
  9.    |-pom.xml

Note
Please check this official guide to understand more.

pom.xml

  1. <project xmlns="http://maven.apache.org/POM/4.0.0" 
  2.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.       xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
  4.  http://maven.apache.org/maven-v4_0_0.xsd">
  5.   <modelVersion>4.0.0</modelVersion>
  6.   <groupId>com.mkyong</groupId>
  7.   <artifactId>CounterWebApp</artifactId>
  8.   <packaging>war</packaging>
  9.   <version>1.0-SNAPSHOT</version>
  10.   <name>CounterWebApp Maven Webapp</name>
  11.   <url>http://maven.apache.org</url>
  12.   <dependencies>
  13.     <dependency>
  14.       <groupId>junit</groupId>
  15.       <artifactId>junit</artifactId>
  16.       <version>3.8.1</version>
  17.       <scope>test</scope>
  18.     </dependency>
  19.   </dependencies>
  20.   <build>
  21.     <finalName>CounterWebApp</finalName>
  22.   </build>
  23. </project>

web.xml – Servlet 2.3 is too old, consider upgrade to 2.5

  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" >
  5. <web-app>
  6.   <display-name>Archetype Created Web Application</display-name>
  7. </web-app>

index.jsp – A simple hello world html file

  1. <html>
  2. <body>
  3. <h2>Hello World!</h2>
  4. </body>
  5. </html>

3. Eclipse IDE Support

To convert the Maven web project to support Eclipse IDE, in terminal, navigate to “CounterWebAPp” folder, issue this command :

  1. mvn eclipse:eclipse -Dwtpversion=2.0

You must add the -Dwtpversion=2.0 argument to make it as a Eclipse web project. Imports it into Eclipse IDE, a globe icon on top of project, means this is a web project in Eclipse.

project structure

You want Eclipse web project NOT Eclipse Java project.
Many users are confused, again, if you just issue mvn eclipse:eclipse, it will only convert the project as Eclipse Java project, add extra -Dwtpversion=2.0 argument to make it as Eclipse web project.

Done. This web project is ready to deploy. Attached to Eclipse’s Tomcat server plugin, and start it.

tomcat in eclipse

You can access the hello world jsp via – http://localhost:8080/CounterWebApp/

4. Update POM

To make above Maven web project to support Spring MVC framework, we need to touch up on the existingpom.xml :

  1. Add compiler plugin to specify JDK6 to compile this project (default is using JDK1.4).
  2. Add Spring frameworks dependencies.
  3. Update jUnit to latest 4.11.

pom.xml

  1. <project xmlns="http://maven.apache.org/POM/4.0.0" 
  2.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
  4.  http://maven.apache.org/maven-v4_0_0.xsd">
  5.     <modelVersion>4.0.0</modelVersion>
  6.     <groupId>com.mkyong</groupId>
  7.     <artifactId>CounterWebApp</artifactId>
  8.     <packaging>war</packaging>
  9.     <version>1.0-SNAPSHOT</version>
  10.     <name>CounterWebApp Maven Webapp</name>
  11.     <url>http://maven.apache.org</url>
  13.     <properties>
  14.         <spring.version>3.0.5.RELEASE</spring.version>
  15.         <junit.version>4.11</junit.version>
  16.         <jdk.version>1.6</jdk.version>
  17.     </properties>
  19.     <dependencies>
  21.         <!-- Spring 3 dependencies -->
  22.         <dependency>
  23.             <groupId>org.springframework</groupId>
  24.             <artifactId>spring-core</artifactId>
  25.             <version>${spring.version}</version>
  26.         </dependency>
  28.         <dependency>
  29.             <groupId>org.springframework</groupId>
  30.             <artifactId>spring-web</artifactId>
  31.             <version>${spring.version}</version>
  32.         </dependency>
  34.         <dependency>
  35.             <groupId>org.springframework</groupId>
  36.             <artifactId>spring-webmvc</artifactId>
  37.             <version>${spring.version}</version>
  38.         </dependency>
  40.         <dependency>
  41.             <groupId>junit</groupId>
  42.             <artifactId>junit</artifactId>
  43.             <version>${junit.version}</version>
  44.             <scope>test</scope>
  45.         </dependency>
  46.     </dependencies>
  47.     <build>
  48.         <finalName>CounterWebApp</finalName>
  49.         <plugins>
  50.             <plugin>
  51.                 <groupId>org.apache.maven.plugins</groupId>
  52.                 <artifactId>maven-compiler-plugin</artifactId>
  53.                 <version>3.0</version>
  54.                 <configuration>
  55.                     <source>${jdk.version}</source>
  56.                     <target>${jdk.version}</target>
  57.                 </configuration>
  58.             </plugin>
  59.         </plugins>
  60.     </build>
  61. </project>

5. Spring MVC REST

Create a Spring MVC controller class, with two simple methods to print a message.

/src/main/java/com/mkyong/controller/BaseController.java

  1. package com.mkyong.controller;
  3. import org.springframework.stereotype.Controller;
  4. import org.springframework.ui.ModelMap;
  5. import org.springframework.web.bind.annotation.RequestMapping;
  6. import org.springframework.web.bind.annotation.RequestMethod;
  8. @Controller
  9. @RequestMapping("/")
  10. public class BaseController { 
  12.     @RequestMapping(value="/welcome", method = RequestMethod.GET)
  13.     public String welcome(ModelMap model) { 
  15.         model.addAttribute("message", "Maven Web Project + Spring 3 MVC - welcome()");
  17.         //Spring uses InternalResourceViewResolver and return back index.jsp
  18.         return "index";
  20.     }
  22.     @RequestMapping(value="/welcome/{name}", method = RequestMethod.GET)
  23.     public String welcomeName(@PathVariable String name, ModelMap model) { 
  25.         model.addAttribute("message", "Maven Web Project + Spring 3 MVC - " + name);
  26.         return "index";
  28.     }
  30. }

Create a Spring configuration file, defines the Spring view resolver.

/src/main/webapp/WEB-INF/mvc-dispatcher-servlet.xml

  1. <beans xmlns="http://www.springframework.org/schema/beans"
  2.     xmlns:context="http://www.springframework.org/schema/context"
  3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.     xsi:schemaLocation="
  5.  http://www.springframework.org/schema/beans 
  6.  http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
  7.  http://www.springframework.org/schema/context 
  8.  http://www.springframework.org/schema/context/spring-context-3.0.xsd">
  10.     <context:component-scan base-package="com.mkyong.controller" />
  12.     <bean
  13.         class="org.springframework.web.servlet.view.InternalResourceViewResolver">
  14.         <property name="prefix">
  15.             <value>/WEB-INF/pages/</value>
  16.         </property>
  17.         <property name="suffix">
  18.             <value>.jsp</value>
  19.         </property>
  20.     </bean>
  22. </beans>

Update existing web.xml to support Servlet 2.5 (the default Servlet 2.3 is too old), and also integrates Spring framework into this web application project via Spring’s listenerContextLoaderListener.

/src/main/webapp/WEB-INF/web.xml

  1. <web-app xmlns="http://java.sun.com/xml/ns/javaee"
  2.           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.           xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
  4.  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
  5.           version="2.5">    
  7.     <display-name>Counter Web Application</display-name>
  9.     <servlet>
  10.         <servlet-name>mvc-dispatcher</servlet-name>
  11.         <servlet-class>
  12.             org.springframework.web.servlet.DispatcherServlet
  13.         </servlet-class>
  14.         <load-on-startup>1</load-on-startup>
  15.     </servlet>
  17.     <servlet-mapping>
  18.         <servlet-name>mvc-dispatcher</servlet-name>
  19.         <url-pattern>/</url-pattern>
  20.     </servlet-mapping>
  22.     <context-param>
  23.         <param-name>contextConfigLocation</param-name>
  24.         <param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
  25.     </context-param>
  27.     <listener>
  28.         <listener-class>
  29.             org.springframework.web.context.ContextLoaderListener
  30.         </listener-class>
  31.     </listener>
  32. </web-app>

Move existing index.jsp inside folder WEB-INF, to protect user access it directly. In additional, edit the file to print out the${message} variable that pass by the controller.

/src/main/webapp/WEB-INF/pages/index.jsp

  1. <html>
  2. <body>
  3. <h2>Hello World!</h2>
  5. <h4>Message : ${message}</h1>    
  6. </body>
  7. </html>

Review the final directory structure

final project structure

6. Eclipse + Tomcat

In order to start or debug this project via Eclipse server plugin (Tomcat or other container). You need to issue following command again, in order to make all dependencies attached to the project web deployment assembly.

  1. mvn eclipse:eclipse -Dwtpversion=2.0

Before this command, project dependencies are empty.

web deployment assembly

After this command, now project dependdencies are here!

web deployment assembly

Important!
Many developers are trapped here, and failed to perform the starting or debugging in Eclipse server plugin, all failed by showing dependencies not found error message. Right click on your project properties, make sure all dependencies are inside the web deployment assembly, otherwise issue mvn eclipse:eclipse -Dwtpversion=2.0 again!

7. Maven Packaging

Review the pom.xml again, the packaging tag defining what is the packaging format or output.

pom.xml

  1. <project ...>
  2.     <modelVersion>4.0.0</modelVersion>
  3.     <groupId>com.mkyong</groupId>
  4.     <artifactId>CounterWebApp</artifactId>
  6.     <packaging>war</packaging>
  7.     <version>1.0-SNAPSHOT</version>

Package the project to deploy is easy, just issue mvn package, it compiles and package the web project into a “war” file and store inproject/target folder.

For example :

  1. $pwd
  2. /Users/mkyong/Documents/workspace/CounterWebApp
  4. Yongs-MacBook-Air:CounterWebApp mkyong$ mvn package
  5. [INFO] Scanning for projects...
  6. [INFO]                                                                         
  7. [INFO] ------------------------------------------------------------------------
  8. [INFO] Building CounterWebApp Maven Webapp 1.0-SNAPSHOT
  9. [INFO] ------------------------------------------------------------------------
  10. [INFO] -- omitted for readability
  11. [INFO] 
  12. [INFO] --- maven-war-plugin:2.1.1:war (default-war) @ CounterWebApp ---
  13. [INFO] Packaging webapp
  14. [INFO] Assembling webapp [CounterWebApp] in [/Users/mkyong/Documents/workspace/CounterWebApp/target/CounterWebApp]
  15. [INFO] Processing war project
  16. [INFO] Copying webapp resources [/Users/mkyong/Documents/workspace/CounterWebApp/src/main/webapp]
  17. [INFO] Webapp assembled in [87 msecs]
  18. [INFO] Building war: /Users/mkyong/Documents/workspace/CounterWebApp/target/CounterWebApp.war
  19. [INFO] WEB-INF/web.xml already added, skipping
  20. [INFO] ------------------------------------------------------------------------
  21. [INFO] BUILD SUCCESS
  22. [INFO] ------------------------------------------------------------------------
  23. [INFO] Total time: 3.936s
  24. [INFO] Finished at: Thu Dec 20 22:28:53 MYT 2012
  25. [INFO] Final Memory: 14M/206M
  26. [INFO] ------------------------------------------------------------------------

Done, just copy the project/target/CounterWebApp.war file and deploy to your container.

8. Demo

Start the web application.

http://localhost:8080/CounterWebApp/welcome

demo1

http://localhost:8080/CounterWebApp/welcome/mkyong

demo2

Download Source Code

Download it – CounterWebApp.zip (13 KB)

References

  1. Apache Maven Project
  2. How To Create A Java Project With Maven
  3. Spring 3 REST Hello World Example
  4. A Simple Web Application

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