Develop GWT application and Deploy it on Google App Engine using Maven

The main goal of this article is to give a complete example in order to develop a complete GWT application , using JSP,JSTL,JPA,GWT-RPC .... , and deploy it on [Google App Engine|http://code.google.com/appengine/] using [maven|http://maven.apache.org/] version either 2 or 3


h2. POM

h3. Dependencies

{code:xml|title=dependencies}

<properties>
<gae.version>1.3.2</gae.version>
<gae.sdk.version>1.3.8</gae.sdk.version>
<datanucleus-jpa.version>2.1.3</datanucleus-jpa.version>
<project_charset>UTF-8</project_charset>
<gwt.version>2.1.0</gwt.version>
</properties>

<dependencies>
<!--
===========================================
TEST DEPS
===========================================
-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
<scope>test</scope>
</dependency>

<!--
===========================================
GAE-API-1.0 DEPS
===========================================
-->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-labs</artifactId>
<version>${gae.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-stubs</artifactId>
<version>${gae.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-runtime</artifactId>
<version>${gae.version}</version>
<scope>test</scope>
</dependency>
<!--
===========================================
GAE-SDK DEPS
===========================================
-->

<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-tools-sdk</artifactId>
<version>${gae.sdk.version}</version>
<scope>test</scope>
</dependency>

<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${gae.sdk.version}</version>
<scope>runtime</scope>
</dependency>
<!--
=======================
DATANUCLEUS
=======================
-->
<dependency>
<groupId>com.google.appengine.orm</groupId>
<artifactId>datanucleus-appengine</artifactId>
<version>1.0.7</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-jta_1.1_spec</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-jpa_3.0_spec</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>javax.jdo</groupId>
<artifactId>jdo2-api</artifactId>
<version>2.3-eb</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-core</artifactId>
<version>2.2.0-m3</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-jpa</artifactId>
<version>${datanucleus-jpa.version}</version>
</dependency>

<!--
=======================
SERVLET,JSP,JSTL
=======================
-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>

<!--
====================================================
GWT DEPS
====================================================
-->
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-servlet</artifactId>
<version>${gwt.version}</version>
<scope>runtime</scope>
</dependency>

<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-user</artifactId>
<version>${gwt.version}</version>
<scope>provided</scope>
</dependency>

<!--
====================================================
JAKARTA COMMONS DEPS
====================================================
-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1.1</version>
<exclusions>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
<exclusion>
<groupId>logkit</groupId>
<artifactId>logkit</artifactId>
</exclusion>
<exclusion>
<groupId>avalon-framework</groupId>
<artifactId>avalon-framework</artifactId>
</exclusion>
</exclusions>
</dependency>
<!--
====================================================
SPRING DEPS
====================================================
-->
<!--
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jpa</artifactId>
<version>2.0.8</version>
<exclusions>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</exclusion>
</exclusions>
</dependency>
-->

<!--
====================================================
STRUTS2 DEPS
====================================================
-->
<!--
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.1.8.1</version>
</dependency>
<dependency>
<groupId>com.opensymphony</groupId>
<artifactId>xwork</artifactId>
<version>2.1.2</version>
<exclusions>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-spring-plugin</artifactId>
<version>2.1.8.1</version>
<exclusions>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</exclusion>
</exclusions>
</dependency>
-->

<!--
====================================================
CUSTOM DEPS
====================================================
-->

</dependencies>


{code}

h3. Plugins

{code:xml|title=plugins}

<plugins>

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.0.2</version>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>

<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>2.1.0</version>
<dependencies>
</dependencies>
<configuration>
<runTarget>it.softphone.rpt.Application/Application.html</runTarget>
<hostedWebapp>${project.build.directory}/${project.build.finalName}</hostedWebapp>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>generateAsync</goal>
<!-- goal>test</goal -->
</goals>
</execution>
</executions>
</plugin>

<plugin>
<groupId>org.datanucleus</groupId>
<artifactId>maven-datanucleus-plugin</artifactId>
<version>2.2.0-release</version>
<dependencies>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-jpa</artifactId>
<version>${datanucleus-jpa.version}</version>
</dependency>
</dependencies>
<configuration>
<mappingIncludes>**/*.class</mappingIncludes>
<verbose>true</verbose>
<enhancerName>ASM</enhancerName>
<api>JPA</api>
</configuration>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>enhance</goal>
</goals>
</execution>
</executions>
</plugin>

<!-- <plugin>
<groupId>org.datanucleus</groupId>
<artifactId>maven-datanucleus-plugin</artifactId>
<version>2.2.0-release</version>
<configuration>
<mappingIncludes>**/Snippet.class</mappingIncludes>
<verbose>true</verbose>
<enhancerName>ASM</enhancerName>
<api>JDO</api>
</configuration>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>enhance</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-core</artifactId>
<version>1.1.5</version>
<exclusions>
<exclusion>
<groupId>javax.transaction</groupId>
<artifactId>transaction-api</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-rdbms</artifactId>
<version>1.1.5</version>
</dependency>
<dependency>
<groupId>org.datanucleus</groupId>
<artifactId>datanucleus-enhancer</artifactId>
<version>1.1.4</version>
</dependency>
</dependencies>
</plugin> -->

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.3</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>2.0-beta-5</version>
<configuration>
<outputEncoding>${project_charset}</outputEncoding>
<inputEncoding>${project_charset}</inputEncoding>
</configuration>
</plugin>

<plugin>
<groupId>net.kindleit</groupId>
<artifactId>maven-gae-plugin</artifactId>
<version>0.7.2</version>
<configuration>
<port>81</port>
<splitJars>true</splitJars>
</configuration>
</plugin>

</plugins>
{code}


h3. Repositories

{code:xml|title=repositories}

<repositories>
<repository>
<id>mvnsearch</id>
<url>http://www.mvnsearch.org/maven2</url>
</repository>
<repository>
<id>datanucleus</id>
<url>http://www.datanucleus.org/downloads/maven2</url>
</repository>
<repository>
<id>gae-plugin</id>
<url>http://maven-gae-plugin.googlecode.com/svn/repository</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>datanucleus</id>
<url>http://www.datanucleus.org/downloads/maven2</url>
</pluginRepository>
<pluginRepository>
<id>gae-plugin</id>
<url>http://maven-gae-plugin.googlecode.com/svn/repository</url>
</pluginRepository>
<pluginRepository>
<id>mvnsearch</id>
<url>http://www.mvnsearch.org/maven2</url>
</pluginRepository>
</pluginRepositories>

{code}