build.xml

<?xml version="1.0"?>
<project name="one-nio" default="build" basedir=".">
    <property name="build.dir"      value="build"/>
    <property name="src.dir"        value="src"/>
    <property name="test.dir"       value="test"/>
    <property name="lib.dir"        value="lib"/>
    <property name="target.jar"     value="${build.dir}/${ant.project.name}.jar"/>
    <property name="download.repo"  value="https://repo1.maven.org/maven2"/>
    <property name="gcc.args"       value="-O3 -fno-omit-frame-pointer -momit-leaf-frame-pointer"/>

    <target name="init">
        <mkdir dir="${build.dir}"/>

        <available file="${lib.dir}" type="dir" property="lib.dir.exists"/>
        <path id="classpath.ref">
            <fileset dir="${lib.dir}" includes="*.jar"/>
        </path>
    </target>

    <target name="retrieve-libs" unless="lib.dir.exists">
        <echo message="Downloading external libraries..."/>
        <mkdir dir="${lib.dir}"/>
        <get src="${download.repo}/org/ow2/asm/asm/9.2/asm-9.2.jar" dest="${lib.dir}/asm-9.2.jar"/>
        <get src="${download.repo}/commons-logging/commons-logging/1.2/commons-logging-1.2.jar" dest="${lib.dir}/commons-logging-1.2.jar"/>
        <get src="${download.repo}/log4j/log4j/1.2.17/log4j-1.2.17.jar" dest="${lib.dir}/log4j-1.2.17.jar"/>
    </target>

    <target name="clean">
        <delete dir="${build.dir}"/>
    </target>

    <target name="clean-all" depends="clean">
        <delete dir="${lib.dir}"/>
    </target>

    <target name="build" depends="build-jar"/>

    <target name="compile-classes" depends="init, retrieve-libs">
        <echo message="Compiling classes..."/>
        <mkdir dir="${build.dir}/classes"/>
        <javac srcdir="${src.dir}" destdir="${build.dir}/classes" classpathref="classpath.ref" includeantruntime="false"/>
    </target>

    <target name="compile-native" depends="init">
        <echo message="Compiling native library..."/>
        <mkdir dir="${build.dir}/native"/>

        <pathconvert property="src.native" pathsep=" ">
            <fileset dir="${src.dir}" includes="**/*.c"/>
        </pathconvert>

        <exec os="Linux" executable="gcc">
            <arg line="-D_GNU_SOURCE -fPIC -shared -Wl,-soname,libonenio.so ${gcc.args}
                       -o ${build.native}/libonenio.so
                       -I ${java.home}/include -I ${java.home}/include/linux
                       -I ${java.home}/../include -I ${java.home}/../include/linux
                       ${src.native} -ldl -lrt"/>
        </exec>
    </target>

    <target name="build-jar" depends="compile-classes, compile-native">
        <echo message="Building ${target.jar}..."/>
        <jar destfile="${target.jar}">
            <fileset dir="${build.dir}/classes" includes="**/*.class" />
            <fileset dir="${build.dir}/native" includes="*.so" />
        </jar>
    </target>
</project>