Ant excels at build process, it is
a build system modeled after make with targets and dependencies. Each target
consists of a set of instructions which are coded in XML. There is a copy task and a javac
task as well as a jar
task.
A Simple Ant build.xml file.
<project name="my-project"
default="dist" basedir=".">
<description>
simple
example build file
</description>
<!-- set
global properties for this build -->
<property
name="src" location="src/main/java"/>
<property
name="build" location="target/classes"/>
<property
name="dist"
location="target"/>
<target
name="init">
<!--
Create the time stamp -->
<tstamp/>
<!--
Create the build directory structure used by compile -->
<mkdir
dir="${build}"/>
</target>
<target
name="compile" depends="init"
description="compile the source " >
<!--
Compile the java code from ${src} into ${build} -->
<javac
srcdir="${src}" destdir="${build}"/>
</target>
<target
name="dist" depends="compile"
description="generate the distribution" >
<!-- Create
the distribution directory -->
<mkdir
dir="${dist}/lib"/>
<!-- Put
everything in ${build} into the MyProject-${DSTAMP}.jar file -->
<jar
jarfile="${dist}/lib/MyProject-${DSTAMP}.jar"
basedir="${build}"/>
</target>
<target
name="clean"
description="clean up" >
<!--
Delete the ${build} and ${dist} directory trees -->
<delete
dir="${build}"/>
<delete
dir="${dist}"/>
</target>
</project>
Contrast the previous Ant example
with a Maven example. In Maven, to create a JAR file from some Java source, all
you need to do is create a simple pom.xml, place your source code
in ${basedir}/src/main/java and then run mvn
install from the command line.
A Sample Maven pom.xml.
That’s all you need in your pom.xml.
Running mvn install from the command
line will process resources, compile source, execute unit tests, create a JAR,
and install the JAR in a local repository for reuse in other projects.
The good thing with Maven that it
is extremely flexible, because it consists of core and numerous plugins that
are accessible in online repositories. Relations between different projects and
subprojects are based on a single source of information POM
(xml) file - Project object Model. One POM
points to another POMs which can have flat or hierarchical structure.
The main advantage to migrate to
Maven are : standardization of
how to handle a project, dependencies are clearly defined, the concept of
artifacts that can be shared to other projects, documentation and reports,
remote and local repository concepts.
A project produces an artifact -
jar, ear, war... The next features are good with Maven:
Dependencies are downloaded
automatically
Standardized, very consistent layout
Standardized, very consistent
naming
Code coverage
Extensive reports
Maven easily works with JUnit tests
