Most of you have experience that we can use Apache Maven to automate build processes. Also we can use Apache Ant forthe same process. But when we use Maven we can resolve our dependencies of the project easily. The only thing required is adding your dependencies to the pom.xml as given bellow.
means if we know all the dependencies exactly, we can use following command to download all the jar files needed to our project.
<dependencies> <dependency> <groupId>org.apache.cxf</groupId> <artifactId>cxf-rt-frontend-jaxws</artifactId> </dependency> <dependency> <groupId>org.apache.cxf</groupId> <artifactId>cxf-rt-transports-http</artifactId> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>compile</scope> </dependency> </dependencies>But when use Apache Ant, we have to do some specifics tasks to resolve dependencies in a intelligent manner. Why I say in a intelligent manner
means if we know all the dependencies exactly, we can use following command to download all the jar files needed to our project.
<get src="http://repo1.maven.org/maven2/org/apache/ivy/ivy/${ivy.install.version}/ivy-${ivy.install.version}.jar" dest="${ivy.jar.file}" usetimestamp="true"/>
But if don't know all the dependency tree, we are in trouble. So in that case we can use Apache Ivy to resolve all the dependencies. Please look at the given Apache Ant build.xml file.<project default="compile-all" xmlns:ivy="antlib:org.apache.ivy.ant">
<property name="classes" value="classes"/>
<property name="src" value="src"/>
<property name="ivy.install.version" value="2.0.0-beta1" />
<property name="ivy.jar.dir" value="${basedir}/ivy" />
<property name="ivy.jar.file" value="${ivy.jar.dir}/ivy.jar" />
<path id="class.path">
<pathelement path="${java.class.path}"/>
<fileset dir="./lib">
<include name="**"/>
</fileset>
</path>
<target name="clean">
<delete dir="${classes}"/>
<delete dir="${lib}"/>
<delete dir="${ivy}"/>
</target>
<target name="init" depends="clean">
<mkdir dir="${classes}"/>
</target>
<!-- #######Downloading and Installing Apache Ivy#######-->
<target name="download-ivy" unless="skip.download" depends="init">
<mkdir dir="${ivy.jar.dir}"/>
<get src="http://repo1.maven.org/maven2/org/apache/ivy/ivy/${ivy.install.version}/ivy-${ivy.install.version}.jar" dest="${ivy.jar.file}" usetimestamp="true"/>
</target>
<target name="install-ivy" depends="download-ivy" >
<path id="ivy.lib.path">
<fileset dir="${ivy.jar.dir}" includes="*.jar"/>
</path>
<taskdef resource="org/apache/ivy/ant/antlib.xml" uri="antlib:org.apache.ivy.ant" classpathref="ivy.lib.path"/>
</target>
<!-- ######################################-->
<!-- ###########Resolving Dependencies Using Ivy######-->
<target name="getDependency" depends="install-ivy">
<ivy:retrieve />
</target>
<!-- ######################################-->
<target name="compile-all" depends="getDependency">
<javac debug="on" destdir="${classes}">
<src path="${src}"/>
<classpath refid="class.path"/>
</javac>
</target>
</project>
Here in this project we need, Junit and Spring Framework for compile and run the project. To get those jars to our project we use Ivy. First of all we have to get Ivy downloaded.
After downloading Ivy we can retrieve our dependencies. Those dependencies have to be specified in file called ivy.xml which exists in the working directory. For this project this is the ivy.xml,<?xml version="1.0" encoding="UTF-8"?> <ivy-module version="2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://ant.apache.org/ivy/schemas/ivy.xsd"> <info organization="andunslg" module="my_project"/> <dependencies> <dependency org="junit" name="junit" rev="4.0" transitive="false"/> <dependency org="org.springframework" name="spring-context" rev="3.0.7.RELEASE" transitive="false"/> <dependency org="org.springframework" name="spring-core" rev="3.0.7.RELEASE" transitive="false"/> <dependency org="org.springframework" name="spring-beans" rev="3.0.7.RELEASE" transitive="false"/> </dependencies> </ivy-module>Here you can see that dependencies are specified in our manner ,
<dependency org="junit" name="junit" rev="4.0" transitive="false"/>In that org, name, version are very important. Because Ivy use those details to download the jars from the public repo. Also in default Ivy download all the transitive dependencies of the jars. We can stop that by saying transitive="false". Ivy will download all the jars to a called lib in the working directory. After that we can use that in our class path. If you need to find org, name, version of your jars, pleas use this link. http://mvnrepository.com/ In that details are given in this way,
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.0.7.RELEASE</version> </dependency>Here groupId=org, artifactId=name. So you can create your ivy.xml using those details. Hope this helps you.Contact me for further clarifications. The follwoing shell output show how this build.xml works,
andunslg@andunslg-Dell-System-Vostro-3450:~/temp$ ant Buildfile: /home/andunslg/temp/build.xml clean: [delete] Deleting directory /home/andunslg/temp/classes init: [mkdir] Created dir: /home/andunslg/temp/classes download-ivy: [get] Getting: http://repo1.maven.org/maven2/org/apache/ivy/ivy/2.0.0-beta1/ivy-2.0.0-beta1.jar [get] To: /home/andunslg/temp/ivy/ivy.jar [get] Not modified - so not downloaded install-ivy: getDependency: No ivy:settings found for the default reference 'ivy.instance'. A default instance will be used no settings file found, using default... [ivy:retrieve] :: Ivy 2.0.0-beta1 - 20071206070608 :: http://ant.apache.org/ivy/ :: :: loading settings :: url = jar:file:/home/andunslg/temp/ivy/ivy.jar!/org/apache/ivy/core/settings/ivysettings.xml [ivy:retrieve] :: resolving dependencies :: wso2#spring;working@andunslg-Dell-System-Vostro-3450 [ivy:retrieve] confs: [default] [ivy:retrieve] found junit#junit;4.0 in public [ivy:retrieve] found org.springframework#spring-context;3.0.7.RELEASE in public [ivy:retrieve] found org.springframework#spring-core;3.0.7.RELEASE in public [ivy:retrieve] found org.springframework#spring-beans;3.0.7.RELEASE in public [ivy:retrieve] :: resolution report :: resolve 1517ms :: artifacts dl 20ms --------------------------------------------------------------------- | | modules || artifacts | | conf | number| search|dwnlded|evicted|| number|dwnlded| --------------------------------------------------------------------- | default | 4 | 0 | 0 | 0 || 4 | 0 | --------------------------------------------------------------------- [ivy:retrieve] :: retrieving :: wso2#spring [ivy:retrieve] confs: [default] [ivy:retrieve] 0 artifacts copied, 4 already retrieved (0kB/30ms) compile-all: [javac] /home/andunslg/temp/build.xml:39: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds [javac] Compiling 1 source file to /home/andunslg/temp/classes BUILD SUCCESSFUL Total time: 12 seconds
