面试题与答案

ANT full form is Another Needed Tool. Ant is a build tool that is java based. A build tool performs the following tasks:

Compiling java code into byte code
Placing this byte code in a package
Deployment to production systems
Document creation and release notes preparation.

Ant is an open source project available under the Apache license. Therefore, its source code can be downloaded and modified. 

Before start using ANT, we should be clear about the project name and the .java files and most importantly, the path where the .class files are to be placed.

For example, we want the application HelloWorld to be used with ant. The Java source files are in a subdirectory called Dirhelloworld, and the .class files are to put into a sub directory called Helloworldclassfiles.

1. The build file by name build.xml is to be written. The script is as follows

The following is the code snippet to set the classpath in ant:

<path id=�build.classpath�>
<fileset dir=�${build.lib}� includes=�**/*.jar/>
<fileset dir=�${build.class�}/>
</path>

<target�.>
<javac�.>
<classpath field=�build.classpath�/>
</javac>
</target>

<target�.>
<javac�.>
<classpath field=�build.classpath�/>
</javac>
</target>

<target name="compile" depends="-init">
<mkdir dir="${build.dir}/classes" />
<javac destdir="${build.dir}/classes" includeantruntime="false" debug="true" optimize="true" verbose="false" deprecation="false" source="1.5" target="1.5">
<classpath refid="classpath.base" />
<src path="${src.dir}/main/java" />
</javac>
</target>

<target name="test" depends="-copytestresources, compile">
<mkdir dir="${build.dir}/junit-reports" />
<junit printsummary="false"
fork="on"
haltonfailure="false"
failureproperty="test.failure">
<classpath refid="classpath.junit" />
<formatter type="plain" />
<batchtest todir="${build.dir}/junit-reports">
<fileset dir="${build.dir}/test-classes" includes="**/*Test.class" />
</batchtest>
</junit>
<junitreport tofile="target/junit-reports/TEST.xml">
<fileset dir="${target}/junit-reports" includes="TEST-*.xml" />
<report format="frames" todir="${target}/junit-reports" />
</junitreport>
</target>

<!-- Import properties from build.properties -->
<property name="build.properties" value="${basedir}/conf/build.properties" />
<fail message="Missing build.properties file: please use -Dbuild.properties=/path/to/file">
<condition>
<not>
<available file="${build.properties}" type="file" />
</not>
</condition>
</fail>
<property file="${build.properties}" />

<path id="classpath.base">
<pathelement location="${glassfish.home}/lib/javaee.jar" />
<fileset dir="${lib.dir}">
<include name="log4j-1.2.15.jar" />
<include name="el-impl-1.0.jar" />
</fileset>
</path>

<target name="clean" depends="-clean" />
<target name="-clean">
<delete dir="${build.dir}/*" />
<delete dir="${build.dir}/classes" />
<delete dir="${build.dir}/test-classes" />
<delete dir="${build.dir}/release" />
<delete file="${build.dir}/*.jar" />
<delete file="${build.dir}/VERSION.txt" />
</target>

<target name="validate" depends="-init">
<mkdir dir="${build.dir}/pmd-reports" />
<pmd shortFilenames="true" rulesetfiles="${basedir}/.ruleset">
<formatter type="xml" tofile="${build.dir}/pmd-reports/report.xml" />
<fileset dir="${src.dir}/main/java/com/" includes="**/*.java" />
<fileset dir="${src.dir}/test/java" includes="**/*.java" />
</pmd>
<xslt style="${ant.home}/etc/xslt/pmd-report-per-class.xslt"
in="${build.dir}/pmd-reports/report.xml"
out="${build.dir}/pmd-reports/report.html" />
</target>