Chapter 12. Extending Ant
There's more to Ant than what comes out of the box because you can extend Ant in various ways. The most common way of extending Ant is by creating your own tasks, and this chapter covers how to do that. You'll learn how to create new tasks, handle task attributes, access property values, work with nested text and elements, make builds fail, work with filesets, use custom tasks as wrappers for external programs, and more.
Besides creating new tasks, you can extend Ant in other ways, such
as using scripting languages such as JavaScript, which I'll explain. You
can even create listeners that respond to build file events by executing
Java code, and create loggers that log data as a build progresses. And you
can create custom filters and selectors, which you can use with some Ant
tasks such as copy
.
Creating a Simple Custom Ant Task
Creating new Ant tasks is simple since all you need is an
execute( )
method. Example 12-1 is a Java class named
Greeting
that displays the text "No
worries.".
Example 12-1. A simple Ant task (ch12/greetingtask/src/Greeting java)
public class Greeting { public void execute( ) { System.out.println("No worries."); } }
To install this class as a new Ant task, you compile this
code and use the taskdef
task to
declare it in Ant. The attributes of the taskdef
task are shown in Table 12-1.
Tip
The taskdef
task is based on
the typedef
task, except that the
values of two attributes, adapter
and adapto
, are preset to fixed values ("org.apache.tools.ant.TaskAdapter" ...
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