Apache ant property files

In Apache Ant, a property file is a file containing a set of key-value pairs that can be used to define properties for a build. Property files can be used to externalize property values from the build file, making it easier to manage and maintain the build process.

Property files are typically stored in plain text format, with each property defined on a separate line using the following syntax:

key=value

Here is an example of a simple property file:

# Sample property file
src.dir=src
build.dir=build

In this example, the property file defines two properties, "src.dir" and "build.dir", with default values of "src" and "build", respectively.

To use a property file in a build, you can use the "property" task to load the properties from the file into the Ant build. Here is an example of how to use the property task to load properties from a file:

<project name="myproject" default="build">
    <property file="build.properties"/>
    
    <target name="compile">
        <javac srcdir="${src.dir}" destdir="${build.dir}"/>
    </target>
    
    <target name="build" depends="compile">
        <property name="jar.name" value="myproject.jar"/>
        <jar destfile="${build.dir}/${jar.name}">
            <fileset dir="${build.dir}">
                <include name="**/*.class"/>
            </fileset>
        </jar>
    </target>
</project>

In this example, the "property" task is used to load the properties from the "build.properties" file, which is located in the same directory as the build file. The properties can then be used in the same way as properties defined in the build file, as shown in the "compile" and "build" targets.

Using property files in this way can make it easier to manage and maintain the build process, as it allows you to externalize configuration values from the build file and easily modify them as needed.