Eclipse 中 external tools configuration 编译项目?

1.eclipse external tools configuration 添加了 如下 xml 文件；

图一

图二

执行 StoreWebWork buildjida.xml ，控制台 输出 内容如下：

StoreWebWork buildjida.xml 代码如下：

<?xml version="1.0"?>

<!-- ======================================================================= -->
<!-- EJB3 EntityBean build file           eclipse  external tools configuration                                            -->
<!-- ======================================================================= -->

<project name="com" default="ejbjar" basedir="..">

    <property environment="env" />
    <property name="app.dir" value="${basedir}/StoreWebWork" />
    <property name="src.dir" value="D:\workspace-yaoxiao2\StoreWebWork\src" />
    <property name="src.dir1" value="D:\workspace-yaoxiao2\StoreWebWork\src\com\jida" />
    <property name="jboss.home" value="D:\jboss-4.2.3.GA\server\yaoxiao2Test\deploy\web.war\WEB-INF\lib" />
    <property name="jboss.server.config" value="all" />
    <property name="build.dir" value="${app.dir}/bin" />
    <property name="build.classes.dir" value="${build.dir}" />

    <!-- Build classpath -->
    <path id="build.classpath">
        <fileset dir="D:\workspace-yaoxiao2\StoreWebWork">
            <include name="*.jar" />
        </fileset>
        <fileset dir="D:\workspace-yaoxiao2\StoreWebWork">
               <include name="comjida.jar" />
        </fileset>
        <pathelement location="${build.classes.dir}" />
    </path>



    <!-- =================================================================== -->
    <!-- Prepares the build directory                                        -->
    <!-- =================================================================== -->
    <target name="prepare" depends="clean">
        <mkdir dir="${build.dir}" />
        <mkdir dir="${build.classes.dir}" />
    </target>

    <!-- =================================================================== -->
    <!-- Compiles the source code                                            -->
    <!-- =================================================================== -->
    <target name="compile" depends="prepare" description="编绎">
        <javac srcdir="${src.dir1}" destdir="${build.classes.dir}" debug="on" deprecation="on" optimize="off" includes="**">
            <classpath refid="build.classpath" />
        </javac>
    </target>

    <target name="ejbjar" depends="compile" description="创建EJB发布包">
        <jar jarfile="${app.dir}/comjida.jar">
            <fileset dir="${build.classes.dir}">
                <include name="**/*.class" />
            </fileset>
            <metainf dir="${src.dir}/META-INF">
                <include name="**" />
            </metainf>
        </jar>
    </target>

    

    <!-- =================================================================== -->
    <!-- Cleans up generated stuff                                           -->
    <!-- =================================================================== -->
    <target name="clean">
        <delete dir="${build.dir}" />
        <delete file="${jboss.home}\comjida.jar" />
    </target>
    <target name="deploy" depends="ejbjar">
            <copy file="${app.dir}\comjida.jar" todir="${jboss.home}" />
    </target>

</project>

问题1： StoreWebWork buildjida.xml 文件 的作用 是什么？ 里面的 参数 、变量 都分别是什么意思？

问题2：图2 中的 参数 、变量 都分别是什么意思？

**

请大神解答，或 提供学习网址 ，感激不尽……

**