Apache Ant is a software tool for automating software build processes for Java applications which originated from the Apache Tomcat project in early 2000 as a replacement for the Make build tool of Unix. It is similar to Make, but is implemented using the Java language and requires the Java platform. Unlike Make, which uses the Makefile format, Ant uses XML to describe the code build process and its dependencies. Released under an Apache License by the Apache Software Foundation, Ant is an open-source project.

History

Ant ("Another Neat Tool") was conceived by James Duncan Davidson while preparing Sun Microsystems's reference JSP and Servlet engine, later Apache Tomcat, for release as open-source. A proprietary version of Make was used to build it on the Solaris platform, but in the open-source world, there was no way of controlling which platform was used to build Tomcat; so Ant was created as a simple platform-independent tool to build Tomcat from directives in an XML "build file". Ant (version 1.1) was officially released as a stand-alone product on July 19, 2000. Several proposals for an Ant version 2 have been made, such as AntEater by James Duncan Davidson, Myrmidon by Peter Donald and Mutant by Conor MacNeill, none of which were able to find large acceptance with the developer community. At one time (2002), Ant was the build tool used by most Java development projects. For example, most open source Java developers included files with their distribution. Because Ant made it trivial to integrate JUnit tests with the build process, Ant allowed developers to adopt test-driven development and extreme programming. In 2004 Apache created a new tool with a similar purpose called Maven. Gradle, which is similar software, was created in 2008, which in contrary uses Groovy (and a few other languages) code instead of XML.

Extensions

WOProject-Ant is just one of many examples of a task extension written for Ant. These extensions are installed by copying their files into ant's directory. Once this is done, these task extensions can be invoked directly in the typical file. The WOProject extensions allow WebObjects developers to use ant in building their frameworks and apps, instead of using Apple's Xcode suite. provides a collection of tasks such as conditional statements and operations on properties as well as other useful tasks. implements tasks and types for networking, Swing user interfaces, JSON processing and other. Other task extensions exist for Perforce, .NET Framework, EJB, and filesystem manipulations.

Example

A sample file is listed below for a simple Java "Hello, world" application. It defines four targets -, , and , each of which has an associated description. The target lists the target as a dependency. This tells Ant that before it can start the target it must first complete the target. Within each target are the actions that Ant must take to build that target; these are performed using built-in tasks. For example, to build the target Ant must first create a directory called (which Ant will do only if it does not already exist) and then invoke the Java compiler. Therefore, the tasks used are and. These perform a similar task to the command-line utilities of the same name. Another task used in this example is named : This Ant task has the same name as the common Java command-line utility, JAR, but is really a call to the Ant program's built-in JAR/ZIP file support. This detail is not relevant to most end users, who just get the JAR they wanted, with the files they asked for. Many Ant tasks delegate their work to external programs, either native or Java. They use Ant's own and tasks to set up the command lines, and handle all the details of mapping from information in the build file to the program's arguments and interpreting the return value. Users can see which tasks do this (e.g., , , ), by trying to execute the task on a system without the underlying program on the path, or without a full Java Development Kit (JDK) installed.

Portability

Ant is intended to work with all systems for which Java runtimes are available. It is most commonly used with Windows, Linux, macOS and other Unix operating systems but has also been used on other platforms such as OS/2, OpenVMS, Solaris, HP-UX. Ant was designed to be more portable than Make. Compared to Make, Ant uses less platform-specific shell commands. Ant provides built-in functionality that is designed to behave the same on all platforms. For example, in the sample file above, the clean target deletes the directory and everything in it. In a Makefile this would typically be done with the command: rm -rf classes/ is a Unix-specific command unavailable in some other environments. Microsoft Windows, for example, would use: rmdir /S /Q classes In an Ant build file the same goal would be accomplished using a built-in command: Additionally, Ant does not differentiate between forward slash or backslash for directories and semicolon or colon for path separators. It converts each to the symbol appropriate to the platform on which it executes.

Limitations

There exist third-party Ant extensions (called antlibs) that provide much of the missing functionality. Also, the Eclipse integrated development environment (IDE) can build and execute Ant scripts, while the NetBeans IDE uses Ant for its internal build system. As both these IDEs are very popular development platforms, they can simplify Ant use significantly. (As a bonus, Ant scripts generated by NetBeans can be used outside that IDE as standalone scripts.)