JDK Tools in OS X

The Java development tools in OS X are similar to the tools you find on other UNIX-based platforms. The command-line tools that Sun provides as part of the JDK for Linux and Solaris are ported for OS X and work just as they do on those platforms. There are only a few significant differences between the standard JDK tools in OS X and those found on other UNIX-based platforms:

• The installed location of the JDK command-line tools is different in OS X. These tools are installed with the rest of JavaVM.framework in /System. The Java tools provided in the default path in /usr/bin/ will execute the version of Java the user has selected as their preferred version for applications in Java Preferences. For more on Java Preferences, see Other Tools. For more information on overall differences in where Java components are in OS X, see Finding Your Way Around.

• tools.jar does not exist. Classes usually located here are instead included in classes.jar. Scripts that rely on the existence of tools.jar need to be rewritten accordingly.

Java IDEs

Java development on any platform often benefits from the use of an Integrated Development Environment (IDE), which provides a more fluid workflow between writing, compiling, running, debugging, and packaging Java code than a simple text editor and the command line. Different IDEs offer unique features and are often suited for different kinds of Java development. These IDEs are industry leaders and offer substantial support for OS X:

• Eclipse IDE for Java Developers (http://www.eclipse.org) is a free download.

• Netbeans IDE (http://www.netbeans.org) is a free download.

• Jetbrains IntelliJ IDEA (http://www.jetbrains.com/idea/) requires a license for continued use after a trial period.

• Xcode (http://developer.apple.com/tools/xcode/) is a free download with a free account from the Apple Developer Connection.

If you are developing a JNI library or intend to have your application communicate with Cocoa, you should plan to use the Xcode Tools for those portions of your development. For more information on JNI development, see JNI.

Xcode Tools

Apple provides a full suite of general developer tools with OS X. This suite of tools, the Xcode Tools, is free but not installed by default. The tools are available for download at the Apple Developer Connection (ADC) Member Site http://connect.apple.com/. If you do not have an ADC membership, you can enroll for various levels of membership, including a free online membership that allows you access to the member site, at http://developer.apple.com/products/.

Xcode

The core component of the OS X development environment is Xcode. Xcode is a complete IDE that allows you to edit, compile, debug, and package Mac apps written in multiple languages. Even if you do not intend to use it for your primary Java development, it is helpful to become familiar with Xcode. Downloadable sample code and the sample code installed in /Developer/Extras/Java/ are both usually provided as Xcode projects. Additionally, there are some elements of documentation viewing that are available only through Xcode.

For more on using Xcode for Java development, see the Xcode Help menu.

The Xcode Organizer

Xcode helps you manage Java applications with the Organizer. You can open it by choosing Organizer from the Window menu. Figure 1 shows the Organizer window.

The Organizer shows your project exactly as it is laid out in the file system. This is in contrast to the main Xcode project windows, which allow you to arrange files arbitrarily without altering their location on disk. The Organizer’s direct reflection of the file system better serves Java development and is similar to other Java IDEs.

To create a new Java project in Xcode, choose New From Template from the New menu in the bottom-left corner of the Organizer.

Xcode and Ant

Xcode uses Apache Ant to compile and run Java applications. You can customize your build settings by modifying the build.xml file that is automatically generated when you create a new Java project. By default, the source and target compiler flags in build.xml are set to 1.3 and 1.2, respectively. This is to ensure compatibility with as many Java versions as possible. Raise these default values to take advantage of APIs and features, such as assertions and generics, that are available only with later versions of Java.

Other Tools

In addition to containing Xcode and Jar Bundler, /Developer/Applications/Utilities/ contains some applications that you can use for Java development though they are not Java-specific:

• Package Maker helps you create an installer PKG for your application.

• File Merge provides a graphical interface for comparing and merging source files.

• Icon Composer helps you create an ICNS file for your application bundle.

Additional development tools for Java and other languages can be found in /usr/share/. Of particular use for Java development are:

• JUnit, a common Java unit-testing framework.

• Apache Ant, a tool for automating builds. The Ant executable can also be found in /usr/bin/.

• Apache Maven, a tool for consolidating multiple elements of development, including dependency management and release management.

• Derby, a lightweight database.

Developer Documentation

Documentation for Java development in OS X is provided both online and as a download from Apple Developer Connection. The most current version of the documentation is available from the Java Reference Library on the Apple Developer Connection website. A snapshot of this documentation is also installed on your computer when you install the Java documentation package. This documentation is easily accessible in Xcode by selecting Documentation from the Help menu. Man pages for the command-line tools are accessible from the command line man program and through the Xcode Help menu.

Sun’s Java SE 6 API documentation is available in /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home/docs.jar. Documentation for Apple’s Java extensions is available in appledocs.jar in the same directory.

Note that Apple does not attempt to provide a full Java documentation suite online or with the Xcode Tools. Sun supplies very thorough documentation available online at http://java.sun.com/reference/docs/. Apple’s documentation only aims to augment Sun’s documentation for Java development issues specific to OS X and to document OS X–specific features of Java. Your primary source for Java platform documentation is Sun’s Java documentation website.