For functionality that is not directly available from Eclipse, Ant provides a back door. Ant is an XML- and Java-based automation tool. Recently, I've been using Ant to auto-deploy application changes to Tomcat and restart that Web application. This tip covers Eclipse's Ant integration, and the following tip, "Automating Tomcat Application Restarts with Ant," explains how to set up Ant to auto-deploy Web application changes and to restart the Web app.
Ant is often executed from the command line, but we Eclipse users can execute Ant directly from our workbench. Eclipse 2.1 and 3.0 will put an Ant icon (which is an image of an actual bug) beside each Ant XML file. The default editor for Ant also nicely color-codes your Ant XML and validates its syntax. The Eclipse Ant editor will also provide an Outline view that lists each Ant target that exists within the XML. Just like with a Java source Outline view, the Ant outline makes it easy to navigate source.
To run an Ant XML script, click your right mouse button on the file in the Package Explorer and select Run Ant from the pop-up menu. A panel labeled "Modify attributes and launch" will be presented; that panel contains six tabs: Main, Refresh, Targets, Classpath, Properties, and Common. The following are short descriptions for each tab:
- Main: This allows for the settings of arguments and directories for the invocation of the Ant main method.
- Refresh: You can use this tab to specify whether or not you want your workspace to automatically be refreshed after the execution of the Ant script.
- Targets: When you click on this tab, it will all the Ant target with checkboxes that you can use to select which targets are to be executed.
- Classpath: This lets you set the classpath to be used by the Ant execution. It also lets you set or override the ANT_HOME environment variable.
- Properties: This lets you set properties that will be accessible to the current execution of the Ant script.
- Common: This tab lets you specify what Eclipse perspective to switch to when Ant is launched. It also lets you add the Ant targets selected to the favorites menu.
To execute my Ant scripts, I select the build.xml file from the Package Explorer by clicking the right mouse button, selecting the Run Ant option, clicking the appropriate target, and clicking the Run button. However, there is a faster way to select the build.xml file. In the icon toolbar, there is a small running man icon that appears to be carrying a brief case. (In Eclipse 2.1, the briefcase is black, but in Eclipse 3.0, it's red.) A single click on the running business man icon will launch Ant. Note that when Ant is launched, its output is placed in the Eclipse console view.