我按照gwt-maven-plugin的说明，生成然后导入下面的项目，
1) 生成项目
$ mvn archetype:generate \
-DarchetypeGroupId=org.codehaus.mojo \
-DarchetypeArtifactId=gwt-maven-plugin \
-DarchetypeVersion=2.5.0
...
Define value for property 'groupId': : org.codehaus.mojo
Define value for property 'artifactId': : gwt-maven-plugin-sample
Define value for property 'version': 1.0-SNAPSHOT: :
Define value for property 'package': org.codehaus.mojo: :
Define value for property 'module': : Sample
...
2）检查生成的POM
<?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/maven-v4_0_0.xsd">
<!-- POM file generated with GWT webAppCreator -->
<modelVersion>4.0.0</modelVersion>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin-sample</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>GWT Maven Archetype</name>
<properties>
<!-- Convenience property to set the GWT version -->
<gwtVersion>2.5.0</gwtVersion>
<!-- GWT needs at least java 1.5 -->
<webappDirectory>${project.build.directory}/${project.build.finalName}</webappDirectory>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-servlet</artifactId>
<version>${gwtVersion}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-user</artifactId>
<version>${gwtVersion}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.0.0.GA</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.0.0.GA</version>
<classifier>sources</classifier>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<!-- Generate compiled stuff in the folder used for developing mode -->
<outputDirectory>${webappDirectory}/WEB-INF/classes</outputDirectory>
<plugins>
<!-- GWT Maven Plugin -->
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>2.5.0</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>test</goal>
<goal>i18n</goal>
<goal>generateAsync</goal>
</goals>
</execution>
</executions>
<!-- Plugin configuration. There are many available options, see
gwt-maven-plugin documentation at codehaus.org -->
<configuration>
<runTarget>Sample.html</runTarget>
<hostedWebapp>${webappDirectory}</hostedWebapp>
<i18nMessagesBundle>org.codehaus.mojo.client.Messages</i18nMessagesBundle>
</configuration>
</plugin>
<!-- Copy static web files before executing gwt:run -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.1.1</version>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>exploded</goal>
</goals>
</execution>
</executions>
<configuration>
<webappDirectory>${webappDirectory}</webappDirectory>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
3）检查生成的项目
gwt-maven-plugin-sample/
├── .classpath
├── pom.xml
├── .project
├── SampleTest-dev.launch
├── SampleTest-prod.launch
├── .settings
│ ├── com.google.appengine.eclipse.core.prefs
│ ├── com.google.gdt.eclipse.core.prefs
│ ├── com.google.gwt.eclipse.core.prefs
│ ├── .jsdtscope
│ ├── org.eclipse.jdt.core.prefs
│ ├── org.eclipse.wst.common.component
│ ├── org.eclipse.wst.common.project.facet.core.xml
│ ├── org.eclipse.wst.jsdt.ui.superType.container
│ └── org.maven.ide.eclipse.prefs
├── src
│ ├── main
│ │ ├── java
│ │ │ └── org
│ │ │ └── codehaus
│ │ │ └── mojo
│ │ │ ├── client
│ │ │ │ ├── GreetingService.java
│ │ │ │ └── Sample.java
│ │ │ ├── server
│ │ │ │ └── GreetingServiceImpl.java
│ │ │ └── shared
│ │ │ └── FieldVerifier.java
│ │ ├── resources
│ │ │ └── org
│ │ │ └── codehaus
│ │ │ └── mojo
│ │ │ ├── client
│ │ │ │ ├── Messages_fr.properties
│ │ │ │ └── Messages.properties
│ │ │ └── Sample.gwt.xml
│ │ └── webapp
│ │ ├── Sample.css
│ │ ├── Sample.html
│ │ └── WEB-INF
│ │ └── web.xml
│ └── test
│ ├── java
│ │ └── org
│ │ └── codehaus
│ │ └── mojo
│ │ └── client
│ │ └── GwtTestSample.java
│ └── resources
│ └── org
│ └── codehaus
│ └── mojo
│ └── SampleJUnit.gwt.xml
└── target
└── generated-sources
└── gwt
└── org
└── codehaus
└── mojo
33 directories, 26 files
4) 在 Eclipse 上，选择“将现有项目导入工作区”
5) 根据gwt-maven-plugin的说明，导入的项目应该有类似下面的项目结构，
最后通过我们比较 4) 和 5)，看到的问题似乎是导入根本没有添加任何 maven 依赖项，换句话说，生成的项目没有被验证为 maven 项目。那么，上面的步骤和下面的配置有什么问题呢？
gwt-maven-plugin 2.5.0
m2e 1.2.0.20120903-1050
eclipse 3.7.2
maven 3.0.4
@编辑
成功运行“mvn gwt:run” ，但未能启动DevMode，GWT Eclipse Plugin
@编辑 2
参考来自的链接@Sachin Shekhar R，我查看了官方 GWT Wiki：使用 maven，按照说明进行操作并测试了 DynaTable RequestFactory 示例。太好了，它确实有效！
不幸的是，Wiki 回应gwt-maven-plugin确实存在archetype使用中的问题。