How To Install Ant

Ant can be installed on almost any operating system in a few easy steps:

1. Install Java Runtime Environment(JRE) or Java Development Kit(JDK). Ant need a JRE or JDK in order to run.
2. 2. Download the ant binary distribution from this link and unzip it to a directory of your choice.
3. 3. Add the location of the bin folder to the path environment variable. For example in windows: PATH=%PATH%;c:\ant\bin
4. 4. Set ANT_HOME environment variable to the location where ant is installed. For example: ANT_HOME=c:\ant

How to create your first ANT project

Any ant project consist of one or more xml files containing the ant tasks. Lets create a small file named “build.xml”, containing only one task to print a small “Hello World!!!”. In order to run you have to go to the directory containing the build.xml file and type and run “ant”.

<project name="how-to-use-ant" basedir="." default="hello-world">

    <target name="hello-world">
        <echo message="Hello World!!!"/>
    </target>
	
</project>

As you noticed we defined in this and project one task named hello-world and this is the default task. If everything goes well, the ant will run (we added in the path the ant bin directory when we installed it) and will print the following text:

Buildfile: build.xml

hello-world:
     [echo] Hello World!!!

BUILD SUCCESSFUL
Total time: 0 seconds

How To Compile and Build Using Ant

In real life we use Ant as the build tool for our applications and Ant is used in 90 percent of the cases for that. I’ve created a separate post to serve as a tutorial. You can check How to Create Jar Files from Ant.

Lets take this time in consideration a real life project. Most of the time Ant is used to compile and build java projects. This means generating, compiling and building jar files. For this we are going to define severals tasks. Lets consider the we create a buid.xml file in the directory where sources are located. The sources are put in the subdirectory called src. We also need to include a jar in the classpath while compiling. We are going to create a separate property file to define the location of this file:

#===================================
#	File Name: build.properties
#===================================

env.LIB=c://java//thirdparty//lib

The ant task contains a few tasks for doing the following operations:
1. Clean the build directory if exists.
2. Create the build directory where the new classes will be built.
3. Compile the java classes.
4. Build a jar file from the java classes.

Here is the build.xml file. Note the dependencies between the tasks and how the properties are defined in the ant xml file or loaded from the properties file:

<project name="how-to-use-ant" basedir="." default="hello-world">

	<property name="build" value="build"/>
	<property file="build.properties"/>
	
	<target name="clean">
		<delete dir="${build}"/>
	</target>

	<target name="init" depends="clean">
		<mkdir dir="${build}"/>
	</target>	
	
	<target name="compile" depends="init">
		<!-- Compile the java code -->
		<javac srcdir="src" destdir="${build}">
			<classpath>
				<pathelement location="${env.LIB}/required-jar1.jar"/>
				<pathelement location="${env.LIB}/required-jar2.jar"/>
			</classpath>
		</javac>
	</target>	
	
	<target name="jar" depends="compile">
		<!-- Build the jar file -->
		<jar basedir="${build}" destfile="${build}/new-jar.jar"/>
	</target>
	
</project>

Now that you’ve seen how to create an ant task you might ask why you need an ant build file for building a jar file. This can be done as well with a few batch commands which will take only a 4 lines bat file. There are certain advantages. The ant files can be easily parametrized and reused, sub projects cand be created, lots of tasks are implemented, covering most of the operations you want to do (junits, sql operations, zip file tasks, tasks for replacing and editing text and xml files, …) and new tasks can be implemented in java and used in any ant file.

Mainly you have to use 2 ant tasks after the java code is generated, one for compiling the classes, the other one to package them. In the following example I’m using ant to generate some jaxb classes, then to compile them and build a jar file. In this task there are 2 ant tasks, named compile and jar, responsible for compiling and generating the ant file:

<?xml version="1.0"?>
<project name="bbindings.jaxb" default="jar" basedir=".">

<property name="home" value="."/>
<property name="build" value="build"/>
<property name="logs" value="logs"/>
<property name="src" value="src"/>
<property file="build.properties"/> 

<target name="clean">
	<delete dir="${logs}"/>
	<delete dir="${build}"/>
	<delete dir="${src}"/>
</target>

<target name="init" depends="clean">
	<mkdir dir="${build}"/>
	<mkdir dir="${logs}"/>
	<mkdir dir="${src}"/>
</target>

<target name="copy_xsd" depends="init">
	<copy file="${env.XSD_FILE}" todir="${src}"/>
</target>       

<target name="generate_jaxb" depends="copy_xsd">
	<java jar="${env.JWSDP_HOME_LIB}\jaxb-xjc.jar" fork="true" dir="${src}">
		<arg value="-p"/>
		<arg value="com.bbindings.jaxb"/>
		<arg value="${home}/${env.XSD_FILE}"/>
	</java>
</target>  

<target name="compile" depends="init,generate_jaxb">
	<!-- Compile the java code -->
	<javac srcdir="${src}" destdir="${build}">
		<classpath>
			<pathelement location="${env.JWSDP_HOME_LIB}/jaxb-api.jar"/>
			<pathelement location="${env.JWSDP_HOME_LIB}/jaxb-impl.jar"/>
			<pathelement location="${env.JWSDP_HOME_LIB}/jaxb-xjc.jar"/>
			<pathelement location="${env.JWSDP_HOME_LIB}/jsr173_api.jar"/>
		</classpath>
	</javac>
</target>
  
<target name="jar" depends="compile">
	<!-- Build the jar file -->
	<jar basedir="${build}" destfile="${build}/${env.JAR_FILE}"/>
</target>

</project>

#===================================
#	File Name: build.properties
#===================================

env.LIB=c://java//thirdparty//lib

The ant task contains a few tasks for doing the following operations:
1. Clean the build directory if exists.
2. Create the build directory where the new classes will be built.
3. Compile the java classes.
4. Build a jar file from the java classes.

Here is the build.xml file. Note the dependencies between the tasks and how the properties are defined in the ant xml file or loaded from the properties file:

<project name="how-to-use-ant" basedir="." default="jar">

	<property name="build" value="build"/>
	<property file="build.properties"/>
	
	<target name="clean">
		<delete dir="${build}"/>
	</target>

	<target name="init" depends="clean">
		<mkdir dir="${build}"/>
	</target>	
	
	<target name="compile" depends="init">
		<!-- Compile the java code -->
		<javac srcdir="src" destdir="${build}">
			<classpath>
				<pathelement location="${env.LIB}/required-jar1.jar"/>
				<pathelement location="${env.LIB}/required-jar2.jar"/>
			</classpath>
		</javac>
	</target>	
	
	<target name="jar" depends="compile">
		<!-- Build the jar file -->
		<jar basedir="${build}" destfile="${build}/new-jar.jar"/>
	</target>
	
</project>

Now that you’ve seen how to create an ant task you might ask why you need an ant build file for building a jar file. This can be done as well with a few batch commands which will take only a 4 lines bat file. There are certain advantages. The ant files can be easily parametrized and reused, sub projects cand be created, lots of tasks are implemented, covering most of the operations you want to do (junits, sql operations, zip file tasks, tasks for replacing and editing text and xml files, …) and new tasks can be implemented in java and used in any ant file.

<project name="springapp" basedir="." default="gen_hibernate">

	<taskdef name="hibernatetool"
			classname="org.hibernate.tool.ant.HibernateToolTask"> 
			<classpath>
				<fileset dir="lib">
					<include name="**/*.jar"/>
				</fileset>
			</classpath>
	</taskdef> 

	<target name="gen_hibernate"
			description="generate hibernate classes">
		<hibernatetool>
		
			<jdbcconfiguration
				configurationfile="hibernate.cfg.xml"
				packagename="com.openversion.bus"  
				detectmanytomany="true"
			/>
			<hbm2hbmxml destdir="src" /> 
			<hbm2java  destdir="src" />
		</hibernatetool>
	</target>

</project>

The following files should be in the lib directory added to classpath (the taskdef section in the above ant task file). Another way to use them is to copy directly in the ant lib folder.

commons-collections.jar
commons-logging.jar
dom4j-1.6.1.jar
freemarker.jar
hibernate-annotations.jar
hibernate-tools.jar
hibernate3.jar
jtidy-r8-20060801.jar
log4j-1.2.14.jar
mysql-connector-java-5.1.5-bin.jar

If you want to generate POJO files and Hibernate .hbm.xml mapping files not for all the tables, then a new hibernate reverse engineering file has to be created specifying the table that should be used and it should be used in the ant script:

...
	<jdbcconfiguration
		configurationfile="hibernate.cfg.xml"
		packagename="com.openversion.bus"
		revengfile="tables.reveng.xml"
		detectmanytomany="true"/>
...

And here is sample tables.reveng.xml file inlcuding all the tables using a matching pattern match-name=”.*”. If you want to select only a few tables you can filter by putting match-name=”table_name” and add as many table-filter tags as many tables you want to include. You also should take care what because the tables names are case sensitive, I lost some time figuring it out.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-reverse-engineering PUBLIC 
	"-//Hibernate/Hibernate Reverse Engineering DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-reverse-engineering-3.0.dtd" >

<hibernate-reverse-engineering>
	<type-mapping>
		<sql-type jdbc-type="BIGINT" hibernate-type="java.lang.Long" not-null="true"></sql-type>
	</type-mapping>
	<table-filter match-name=".*" match-catalog="openversion"></table-filter>
</hibernate-reverse-engineering>

For further reference you can check Chapter 4. Ant Tools and if you need more details about reverse engineering file () you can check Chapter 5. Controlling reverse engineering of the Hibernate Tools Reference Guide.