Command Line Tools

The GWT includes a set of tools that can be run from the command-line to simplify and speed up common tasks.

  1. Configuring Your Path
  2. webAppCreator
  3. i18nCreator

Configuring your PATH

To easily invoke the command-line tools without entering their full path names, add them to your system command search path. To do this, in the PATH environment variable, identify the directory in which you unpacked the GWT distribution.

Windows

  1. Right-click on My Computer and select Properties
  2. Open the Advanced tab.
  3. Click the Environment Variables button.
  4. From the user variables list, select Path and click Edit
  5. At the end of the of the variable value, add a semicolon followed by the full path to the directory where you unpacked the GWT distribution (e.g., ;C:\gwt-2.0.0\).

Mac or Linux

Edit a file named .profile or .bash_profile in your home directory. For example, if you unpacked GWT in /home/user/gwt-2.0.0/, update your profile as follows:

PATH=$PATH:/home/user/gwt-2.0.0/
export PATH

You will need to log out of your account and log back in before the PATH setting takes effect.

webAppCreator

A command-line tool that generates a starter application and scripts for launching development mode and compiling to JavaScript. Use the files generated by these scripts as a starting point for building your own project.

    webAppCreator [-[no]overwriteFiles] [-[no]ignoreExistingFiles] \
                  [-templates template1,template2,...] [-out dir] \
                  [-junit pathToJUnitJar] [-[no]maven] [-[no]ant] moduleName
Parameter Definition
-[no]overwriteFiles Overwrite any existing files. (defaults to OFF)
-[no]ignoreExistingFiles Ignore any existing files; do not overwrite. (defaults to OFF)
-templates Specifies the template(s) to use (comma separeted). Defaults to 'sample,ant,eclipse,readme'
-out The directory to write output files into (defaults to current)
-junit Specifies the path to your junit.jar (optional)
-[no]maven DEPRECATED: Create a maven2 project structure and pom file (default disabled). Equivalent to specifying 'maven' in the list of templates. (defaults to OFF)
-[no]ant DEPRECATED: Create an ant configuration file. Equivalent to specifying 'ant' in the list of templates. (defaults to OFF)
moduleName The name of the module to create (e.g. com.example.myapp.MyApp)

Examples

You can select either ant or maven build system. Based on your selection you will get a different build script, and a different folder structure.

Since nowadays Maven is widely used and importing maven projects in IDE is easier, it's better that you select it for your new GWT projects.

Creating a Maven project.

webAppCreator -out foo -templates maven,sample,readme com.example.foo.Foo

The generated files are used as follows:

  • Running mvn gwt:run from the command-line brings up the new application in superDevMode.
  • Running mvn package from the command-line translates the Java app to JavaScript, creating a war file into the target directory.
  • The other files in src implement a small sample GWT application, with the appropriate web.xml file and tests.

Note: because of a bug in GWT-2.7.0, it generates a broken pom.xml, hence, you have to modify the <dependencyManagement> block to include the <type> parameter:

<dependencyManagement>
  <dependencies>
    <!-- ensure all GWT deps use the same version (unless overridden) -->
    <dependency>
      <groupId>com.google.gwt</groupId>
      <artifactId>gwt</artifactId>
      <version>${gwtVersion}</version>
      <scope>import</scope>
      <type>pom</type>
   </dependency>
 </dependencies>
</dependencyManagement>

Creating an Ant project.

webAppCreator -junit /path/to/junit-3.8.1.jar -out foo com.example.foo.Foo

The generated files are used as follows:

  • Running ant devmode from the command-line brings up the new application in superDevMode.
  • Running ant build from the command-line translates the Java app to JavaScript, creating a web folder called foo in the war directory.
  • Foo.launch is a launch configuration for Eclipse.
  • FooTest-dev.launch is a launch configuration for Eclipse that will run the project's tests in development mode.
  • FooTest-prod.launch is a launch configuration for Eclipse that will run the project's tests in production mode.
  • The other files implement a small sample GWT application.

You will notice that the build.xml file contains a number of rules to compile and deploy your application. These will help to resolve the libraries needed at compile-time and runtime to compile and deploy your application, respectively.

Notice also that there are some properties that you might like to extract to a build.properties file, such as the gwt.sdk property, to make it easier to share the same build script with teammates who may have different configurations on their development machines. Also, this build.xml file serves as an excellent base to grow on as your project takes on more dependencies or requires more specific build targets (for example, unit testing targets).

i18nCreator

A command-line tool that generates scripts to help with static string internationalization, along with sample properties files. Modify the .properties files to suit your project. Run the generated <classname>-i18n script to (re)generate a Java interface for accessing the tags defined in your properties files.

i18nCreator [-eclipse projectName] [-out dir] [-[no]overwriteFiles] \
            [-[no]createConstantsWithLookup] [-[no]createMessages] \
            [-[no]ignoreExistingFiles] interfaceName
Parameter Definition
 -eclipse  Creates a i18n update launch config for the named eclipse project.
 -out  The directory to write output files into (defaults to current)
 -[no]overwriteFiles  Overwrite any existing files. (defaults to OFF)
 -[no]createConstantsWithLookup  Create scripts for a ConstantsWithLookup interface rather than a
 -[no]createMessages  Create scripts for a Messages interface rather than a Constants one. (defaults to OFF)
 -[no]ignoreExistingFiles  Ignore any existing files; do not overwrite. (defaults to OFF)
 interfaceName  The fully qualified name of the interface to create

Example

~/Foo> i18nCreator -eclipse Foo -createMessages com.example.foo.client.FooMessages
 Created file src/com/example/foo/client/FooMessages.properties
 Created file FooMessages-i18n.launch
 Created file FooMessages-i18n

Running FooMessages-i18n will generate an interface class in a file named FooMessages.java from FooMessages.properties that extends Messages (The messages will take parameters, substituting {n} with the nth parameter).

~/Foo> i18nCreator -eclipse Foo com.example.foo.client.FooConstants
 Created file src/com/example/foo/client/FooConstants.properties
 Created file FooConstants-i18n.launch
 Created file FooConstants-i18n

Running FooConstants-i18n will generate an interface from FooConstants.properties that extends Constants (The constants will not take parameters). To create a ConstantsWithLookup class, pass the -createConstantsWithLookup option.

In both examples, The launch configurations do the same thing as the scripts, but are intended to be run from within the Eclipse IDE.

Tip: When new entries are added to the properties file, the -i18n scripts must be run again.

See Also