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>