Try to run ant command from project directory where build.xml is located so that our java program will be compiled and run by ant. Inside classes folder we can find.class file generated once compile target executed successfully.

Ant Tutorial

Ant - Executing Java code. Previous Page. You can use Ant to execute Java code. In the following example, the java class takes in an argument (administrator's email address) and sends out an email.
Ant - Executing Java code. Previous Page. You can use Ant to execute Java code. In the following example, the java class takes in an argument (administrator's email address) and sends out an email.

Ant Useful Resources

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ANT stands for Another Neat Tool. It is a Java-based build tool from Apache. Before going into the details of Apache Ant, let us first understand why we need a build tool in the first place.

Need for a Build Tool

On an average, a developer spends a substantial amount of time doing mundane tasks like build and deployment that include:

Compiling the code
Packaging the binaries
Deploying the binaries to the test server
Testing the changes
Copying the code from one location to another

To automate and simplify the above tasks, Apache Ant is useful. It is an Operating System build and deployment tool that can be executed from the command line.

History of Apache Ant

Ant was created by James Duncan Davidson (the original author of Tomcat).
It was originally used to build Tomcat, and was bundled as a part of Tomcat distribution.
Ant was born out of the problems and complexities associated with the Apache Make tool.
Ant was promoted as an independent project in Apache in the year 2000. The latest version of Apache Ant as on May 2014 is 1.9.4.

Features of Apache Ant

Ant is the most complete Java build and deployment tool available.
Ant is platform neutral and can handle platform specific properties such as file separators.
Ant can be used to perform platform specific tasks such as modifying the modified time of a file using 'touch' command.
Ant scripts are written using plain XML. If you are already familiar with XML, you can learn Ant pretty quickly.
Ant is good at automating complicated repetitive tasks.
Ant comes with a big list of predefined tasks.
Ant provides an interface to develop custom tasks.
Ant can be easily invoked from the command line and it can integrate with free and commercial IDEs.

Apache Ant Ant is distributed under the Apache Software License, a fully-fledged open source license certified by the open source initiative.

The latest Apache Ant version, including its full-source code, class files, and documentation can be found at http://ant.apache.org.

Installing Apache Ant

It is assumed that you have already downloaded and installed Java Development Kit (JDK) on your computer. If not, please follow the instructions here.

Ensure that the JAVA_HOME environment variable is set to the folder where your JDK is installed.
Download the binaries from http://ant.apache.org
Unzip the zip file to a convenient location c:folder. using Winzip, winRAR, 7-zip or similar tools.
Create a new environment variable called ANT_HOME that points to the Ant installation folder, in this case c:apache-ant-1.8.2-bin folder.
Append the path to the Apache Ant batch file to the PATH environment variable. In our case this would be the c:apache-ant-1.8.2-binbin folder.

Verifying Apache Ant Installation

To verify the successful installation of Apache Ant on your computer, type ant on your command prompt.

You should see an output similar to:

If you do not see the above output, then please verify that you have followed the installation steps properly.

Installing Eclipse

This tutorial also covers integration of Ant with Eclipse IDE. Hence, if you have not installed Eclipse already, please download and install Eclipse

To install Eclipse:

Download the latest Eclipse binaries from www.eclipse.org
Unzip the Eclipse binaries to a convenient location, say c:folder
Run Eclipse from c:eclipseeclipse.exe

Typically, Ant's build file, called build.xml should reside in the base directory of the project. However there is no restriction on the file name or its location. You are free to use other file names or save the build file in some other location.

For this exercise, create a file called build.xml anywhere in your computer with the following contents in it:

Note that there should be no blank line(s) or whitespace(s) before the xml declaration. If you allow them, the following error message occurs while executing the ant build -

The processing instruction target matching '[xX][mM][lL]' is not allowed.All build files require the project element and at least one target element.

The XML element project has three attributes :

Attributes	Description
name	The Name of the project. (Optional)
default	The default target for the build script. A project may contain any number of targets. This attribute specifies which target should be considered as the default. (Mandatory)
basedir	The base directory (or) the root folder for the project. (Optional)

A target is a collection of tasks that you want to run as one unit. In our example, we have a simple target to provide an informational message to the user.

Targets can have dependencies on other targets. For example, a deploy target may have a dependency on the package target, the package target may have a dependency on the compile target and so forth. Dependencies are denoted using the depends attribute. For example:

The target element has the following attributes:

Attributes	Description
name	The name of the target (Required)
depends	Comma separated list of all targets that this target depends on. (Optional)
description	A short description of the target. (optional)
if	Allows the execution of a target based on the trueness of a conditional attribute. (optional)
unless	Adds the target to the dependency list of the specified Extension Point. An Extension Point is similar to a target, but it does not have any tasks. (Optional)

The echo task in the above example is a trivial task that prints a message. In our example, it prints the message Hello World.

To run the ant build file, open up command prompt and navigate to the folder where the build.xml resides, and type ant info. You could also type ant instead. Both will work, because info is the default target in the build file. You should see the following output:

Ant build files are written in XML, which does not allow declaring variables as you do in your favorite programming language. However, as you may have imagined, it would be useful if Ant allowed declaring variables such as project name, project source directory, etc.

Ant uses the property element which allows you to specify properties. This allows the properties to be changed from one build to another or from one environment to another.

By default, Ant provides the following pre-defined properties that can be used in the build file:

Properties	Description
ant.file	The full location of the build file.
ant.version	The version of the Apache Ant installation.
basedir	The basedir of the build, as specified in the basedir attribute of the project element.
ant.java.version	The version of the JDK that is used by Ant.
ant.project.name	The name of the project, as specified in the name atrr

Ant Execute Java Program