Tutorial Setup

To complete this tutorial, you'll need the proper versions of Java and Maven. Maven is a useful build automation/packaging tool for Java projects that manages build execution and also dependencies.

Required Java version

We recommend using Java 7, preferably the Enterprise Edition.

If you have Java 8, you must specify Java 7 as the source and the target. In Maven, you do this in the pom.xml file for your project, within the maven-compiler-plugin configuration settings:

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <version>3.2</version>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>7</source>
                <target>7</target>
            </configuration>
        </plugin>

This will result in an application you can deploy and run on production App Engine, since the production instances are Java 7. However, if you have Java 8 on your development machine, and you try to run this app locally using the development server, you'll be running on Java 8 and so you may experience some compatibility issues even with the application compiled for Java 7 as described. For local testing, we recommend the use of the Java 7 SDK.

Downloading Java

If you don't have Java, follow these instructions to download the Java Development Kit (JDK) for Java version 7:

1. Download and install the JDK.

2. Set your JAVA_HOME environment variable. If you use the bash shell:

   1. For a typical Linux installation, add a line similar to the following to your .bashrc file:

      export JAVA_HOME=/usr/local/tools/java/<jdk_version>
      

      where <jdk_version> is your JDK version, for example, jdk1.7.0_45.jdk.

   2. If you use Mac OSX and the default Terminal app, your shell session doesn't load .bashrc by default. So you may need to add a line similar to the following to your .bash_profile:

      [ -r ~/.bashrc ] && source ~/.bashrc
      

   3. If you use Mac OSX but you use a different terminal application such as tmux, you may need to add a line similar to the following line to your .bashrc file:

      export JAVA_HOME=/Library/Java/JavaVirtualMachines/<jdk_version>/Contents/Home
      

      where <jdk_version> is your JDK version, for example, jdk1.7.0_45.jdk.

      Alternatively, if your OS supports /usr/libexec/java_home, you can request the current JDK version in your export command line, as follows:

      export JAVA_HOME=$(/usr/libexec/java_home -v 1.7)
      

Required Maven version

This tutorial requires Apache Maven 3.1 or greater. To determine whether Maven is installed and which version you have, invoke the following command:

 mvn -v

This command should display a long string of information beginning with something like Apache Maven 3.1.0.

If Maven isn't installed on your machine, you can download Maven from the Apache Maven website, and install it using the Apache Maven instructions.

The Google App Engine SDK and Maven

When you use Maven, you don't need to download the Java libraries from the Google App Engine SDK. Maven does that for you. You'll also use Maven to test your app locally and upload (deploy) it to production App Engine.

Creating the Project >>