Here is a small example:
<?xml version="1.0" encoding="UTF-8"?>
<project name="compile" default="main" basedir="../.">
<property name="build.compiler" value="org.eclipse.jdt.core.JDTCompilerAdapter"/>
<property name="root" value="${basedir}/src"/>
<property name="destdir" value="d:/temp/bin" />
<target name="main">
<javac srcdir="${root}" destdir="${destdir}" debug="on" nowarn="on" extdirs="d:/extdirs" source="1.4">
<classpath>
<pathelement location="${basedir}/../org.eclipse.jdt.core/bin"/>
</classpath>
</javac>
</target>
</project>
The syntax used for the javac Ant task can be found in the Ant javac task documentation. The current adapter supports the Javac Ant task 1.4.1 up to 1.6.5 versions.
If you are using a version above 1.5.0, you can use the nested compiler argument element (<compilerarg>) to specify compiler specific options.
...
<javac srcdir="${root}" destdir="${destdir}" debug="on" nowarn="on" extdirs="d:/extdirs" source="1.4">
<classpath>
<pathelement location="${basedir}/../org.eclipse.jdt.core/bin"/>
</classpath>
<compilerarg compiler="org.eclipse.jdt.core.JDTCompilerAdapter" line="-1.5 -warn:+boxing"/>
</javac>
...
Note:
1. To prevent compiler dependant buildfiles, we strongly advise you to use a <compilerarg> whose "compiler" attribute value is org.eclipse.jdt.core.JDTCompilerAdapter. If this is not set, the buildfile can only be used with the Eclipse compiler. If set, the nested compiler argument is ignored if the name is different from the compiler name specified by the build.compiler property.
2. <compilerarg> should not be used to set values like target value, source value, debug options, or any options that could be set using the defined attributes of the javac ant task. Its usage must be reserved to pass compiler specific options like warning options. When a command-line argument is specified more than once, the Eclipse batch compiler can report errors like:
duplicate target compliance setting specification: 1.5