Introduction to ANT

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Introduction to ANT

• Written by James Duncan Davidson• Like GNU Make but specifically for Java• Good for bundling and delivery of groups of classes, jars, wars• Handles dependencies automatically• Written in XML • Works on Unix or Windows• Available from Apache.org

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Ant programs are XML documents

The meaning of the tags is not defined by XML.

XML documents can be programs (we’ll see this again with XSLT).

The software that reads the Ant documents does twothings: -- parses the document (already available to the creator of Ant) -- interprets and executes Ant tasks based on agreed upon semantics

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Some Ant Notes

• Exactly on project element is required• There may be many properties, targets and tasks• At least on target is required• Targets describe broad goals• Tasks are nested within targets• Over 100 core tasks available (e.g. mkdir, javac)• Properties are name-value pairs• Ant interprets the build file with a breadth first traversal across the XML elements under project• Inside a target, Ant performs a depth first traversal• By default, Ant breaks at the first error

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First Example build.xml<?xml version="1.0"?><project basedir="." default="run">

<target name="compile"> <javac srcdir="." destdir="." classpath="." /> </target> <target name="run" depends="compile"> <java classname="MyJava" /> </target></project>

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MyJava.java

public class MyJava {

public static void main(String a[]) {

System.out.println("Hello world"); }}

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Ant Execution

D:\McCarthy\www\95-733\examples\ant2>antBuildfile: build.xml

compile: [javac] Compiling 1 source file to D:\McCarthy\www\95-733 \examples\ant2

run: [java] Hello world

BUILD SUCCESSFULTotal time: 17 seconds

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Second Example build.xml

examples | --- antdir | | | --- SomeCoolClass.class | --- SomeCoolClass.java --- ant2 | --- build.xml --- MyClass.java

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SomeCoolClass.java

D:\McCarthy\www\95-733\examples\antdir>type SomeCoolClass.java

public class SomeCoolClass {

int x;

public SomeCoolClass() { x = 3; } public int getX() { return x; }

}

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MyJava.java

D:\McCarthy\www\95-733\examples\ant2>type MyJava.javapublic class MyJava {

public static void main(String a[]) {

SomeCoolClass p = new SomeCoolClass();

System.out.println("Hello world x == " + p.getX());

}}

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build.xmlD:\McCarthy\www\95-733\examples\ant2>type build.xml<?xml version="1.0"?><project basedir="." default="run"> <target name="compile"> <javac srcdir="." destdir="." > <classpath> <pathelement path="../antdir/"/> <pathelement path="."/> </classpath>

</javac> </target>

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build.xml (Continued)

<target name="run" depends="compile">

<java classname="MyJava"> <classpath> <pathelement path="../antdir/"/> <pathelement path="."/> </classpath> </java> </target></project>

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Ant Exceution

D:\McCarthy\www\95-733\examples\ant2>antBuildfile: build.xml

compile:

run: [java] Hello world x == 3

BUILD SUCCESSFULTotal time: 3 seconds

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Same Example Different build.xml

<?xml version="1.0"?><project basedir="." default="run">

<path id="project.class.path"> <pathelement path="."/> <pathelement path="../antdir/"/> </path>

<target name="compile"> <javac srcdir="." destdir="." > <classpath refid="project.class.path"/> </javac> </target>

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<target name="run" depends="compile">

<java classname="MyJava"> <classpath refid="project.class.path"/> </java> </target></project>

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Ant Example from “Ant The Definitive Guide” O’reilly

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Initial LayoutD:\McCarthy\www\95-733\examples\ant>tree /f

Directory PATH listing

Volume serial number is 0012FC94 486D:D392

D:.

│ build.xml

│

└───src

└───com

└───oreilly

└───sample

Account.java

Person.java

PersonTest.java

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After ant all

D:.│ build.xml│├───build│ ├───classes│ │ └───com│ │ └───oreilly│ │ └───sample│ │ Account.class│ │ Person.class│ │ PersonTest.class│ ││ └───lib│ orielly.jar

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After ant all (continued)

│└───src └───com └───oreilly └───sample Account.java Person.java PersonTest.java

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build.xml<?xml version="1.0" ?><!-- build.xml -->

<project name = "Simple BuildFile" default="compile" basedir=".">

<!-- the directory containing source code -->

<property name = "src.dir" value = "src" />

<!-- Temporary build directories -->

<property name = "build.dir" value = "build" />

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<property name = "build.classes" value = "${build.dir}/classes" />

<property name = "build.lib" value = "${build.dir}/lib" />

<!-- Target to create the build directories prior to compile -->

<target name = "prepare"> <mkdir dir= "${build.dir}" /> <mkdir dir= "${build.classes}" /> <mkdir dir= "${build.lib}" /> </target>

<target name = "clean" description = "Remove all generated files." > <delete dir ="${build.dir}" /> </target>

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<target name = "compile" depends = "prepare" description = "Compiles all source code." >

<javac srcdir = "${src.dir}" destdir= "${build.classes}" /> </target>

<target name = "jar" depends = "compile" description = "Generates oreilly.jar in the 'dist' directory. "> <!-- exclude the test class from the jar file --> <jar jarfile="${build.lib}/orielly.jar" basedir="${build.classes}" excludes = "**/*PersonTest.class" /> </target>

<target name = "all" depends = "clean,jar" description = "Cleans, compiles, then builds the Jar file." /></project>