使用ant构建有依赖库的项目

我们来看看一个build脚本

<project xmlns:ivy="antlib:org.apache.ivy.ant"
name="dateUtilsProject" default="main" basedir=".">
<description>
Create a Java Project (JAR) with Ant build script
</description>

<property name="projectName" value="DateUtils" />
<property name="src.dir" location="src" />
<property name="build.dir" location="bin" />
<property name="dist.dir" location="dist" />
<property name="dist.lib.dir" location="dist/lib" />
<property name="lib.dir" value="lib" />
<property name="main-class" value="com.mkyong.core.utils.DateUtils" />

<!-- ivy start -->
<!-- ivy to get dependencies and copy to project lib folder automatically -->
<target name="resolve" description="retrieve dependencies with ivy">
<ivy:retrieve />
</target>

<!-- install ivy -->
<target name="ivy" description="Install ivy">
<mkdir dir="${user.home}/.ant/lib" />
<get dest="${user.home}/.ant/lib/ivy.jar" src="http://search.maven.org/remotecontent?filepath=org/apache/ivy/ivy/2.4.0-rc1/ivy-2.4.0-rc1.jar" />
</target>
<!-- ivy end -->

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

<!-- external libraries classpath, we don't need sources and javadoc -->
<path id="classpath">
<fileset dir="${basedir}/">
<include name="${lib.dir}/*.jar" />
<exclude name="${lib.dir}/*sources.jar"/>
<exclude name="${lib.dir}/*javadoc.jar"/>
</fileset>
</path>

<!-- To work with external libraries, need classpath to compile -->
<target name="compile" depends="init" description="compile the source ">
<javac includeantruntime="false" srcdir="${src.dir}" destdir="${build.dir}" classpathref="classpath" />
</target>

<!-- constructs the external libraries classpath name -->
<pathconvert property="classpath.name" pathsep=" ">
<path refid="classpath" />
<mapper>
<chainedmapper>
<flattenmapper />
<globmapper from="*.jar" to="lib/*.jar" />
</chainedmapper>
</mapper>
</pathconvert>

<target name="copy-dependencies">
<copy todir="${dist.lib.dir}">
<fileset dir="${lib.dir}" includes="**/*.jar" excludes="**/*sources.jar, **/*javadoc.jar" />
</copy>
</target>

<!-- jar it, and declares the ext libraries in manifest.mf file -->
<target name="jar" depends="compile, copy-dependencies" description="package, output to JAR">

<echo message="classpath.name : ${classpath.name} " />

<mkdir dir="${dist.dir}" />
<mkdir dir="${dist.lib.dir}" />

<jar jarfile="${dist.dir}/${projectName}.jar" basedir="${build.dir}">
<manifest>
<attribute name="Main-Class" value="${main-class}" />
<attribute name="Class-Path" value="${classpath.name}" />
</manifest>
</jar>
</target>

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

<!-- Default, run this -->
<target name="main" depends="clean, compile, jar" />

</project>

看起来很复杂,但还是比较简单的, 虽然在此之前我没学过ant, 现在也是看着build脚本学习的, 以后真正在项目使用ant还是需要去看doc的

首先我们看看

<!-- ivy start -->
<!-- ivy to get dependencies and copy to project lib folder automatically -->
<target name="resolve" description="retrieve dependencies with ivy">
<ivy:retrieve />
</target>我们在resolve中添加了ivy的检索, ivy就会

<!-- install ivy -->
<target name="ivy" description="Install ivy">
<mkdir dir="${user.home}/.ant/lib" />
<get dest="${user.home}/.ant/lib/ivy.jar"
src="http://search.maven.org/remotecontent?filepath=org/apache/ivy/ivy/2.4.0-rc1/ivy-2.4.0-rc1.jar" />
</target>
<!-- ivy end -->

接着执行clean, compile

<!-- To work with external libraries, need classpath to compile -->
<target name="compile" depends="init" description="compile the source ">
<javac includeantruntime="false" srcdir="${src.dir}" destdir="${build.dir}" classpathref="classpath" />
</target>

需要理解的是

classpathref="classpath"

classpath指向的是ivy帮我们下载的lib目录

<!-- external libraries classpath, we don't need sources and javadoc -->
<path id="classpath">
<fileset dir="${basedir}/">
<include name="${lib.dir}/*.jar" />
<exclude name="${lib.dir}/*sources.jar"/>
<exclude name="${lib.dir}/*javadoc.jar"/>
</fileset>
</path>

上面中我们的classpath指向ivy下载lib,是没问题的,当是我们程序打包时是需要这些文件的, 所以我们需要把这些文件copy到dist中

<target name="copy-dependencies">
<copy todir="${dist.lib.dir}">
<fileset dir="${lib.dir}" includes="**/*.jar" excludes="**/*sources.jar, **/*javadoc.jar" />
</copy>
</target>

最后打包时我们需要在清单文件(MANIFEST.MF)添加lib的路径

<jar jarfile="${dist.dir}/${projectName}.jar" basedir="${build.dir}">
<manifest>
<attribute name="Main-Class" value="${main-class}" />
<attribute name="Class-Path" value="${classpath.name}" />
</manifest>
</jar>