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MacOS X Server Release Notes Copyright \xa9 1998 by Apple Computer, Inc. All Rights Reserved.

Mac OS X Server Developer Release Notes:
Java Virtual Machine

These notes are for the Java^TM virtual machine of Rhapsody Release 1.0. The Java virtual machine enables the use of Java programs in Rhapsody. This implementation of the Java virtual machine on Rhapsody platforms is based on the Java Development Kit (JDK) version 1.1.6.

Documentation of the JDK 1.1.6 APIs is available on from Javasoft (http://www.javasoft.com/). On Rhapsody, a subset of the JDK 1.1.6 API documentation is stored in HTML format in /System/Library/Frameworks/JavaVM.framework/Resources/English.lproj/Documentation/Java/packages.html.

Notes Specific to Release 1.0

The Java virtual machine consists of two parts:

• An implementation of the Java Development Kit 1.1.6 for Rhapsody.
  
  
• The JavaVM framework, a set of Objective-C classes, used to load and call a virtual machine from Objective C.

Both parts are stored in the /System/Library/Frameworks/JavaVM.framework directory.

Features

Commands

You can run the following commands, located in /usr/bin, from the command line:

java

Java interpreter, which executes Java programs.

javac

Java language compiler, which translates programs written in Java into bytecodes executable by the Java interpreter .

javah

Creates C header files used to interface programs written in Java with code written in C .

javap

Bytecode disassembler.

jar

Packages multiple files into a Java archive.

javadoc

Generates documentation in HTML format from Java source code.

jdb

Java debugger.

appletviewer

Enables the standalone execution of applets.

Environment Variables

The Java virtual machine is using the following environment variables:

CLASSPATH

Extends the path the Java virtual machine uses for looking up class files. The default class path (~/Library/Java:/Local/Library/Java:/System/Library/Java:/Network/Library/Java:/System/Library/Frameworks/JavaVM.framework/Classes/classes.jar:/System/Library/Frameworks/JavaVM.framework/Classes/awt.jar:/System/Library/Frameworks/JavaVM.framework/Classes/swingall.jar) is always appended to this variable. If the variable is not defined in the environment, only the default class path is used.

 

Specifying a class path on the command line using the -classpath option overrides this variable. In this case, the default class path is not automatically appened to the class path specified on the command line.

 

JAVA_HOME

Sets the java.home property in the system properties. Defaults to /System/Library/Frameworks/JavaVM.framework/Home.

 

JAVA_COMPILER

Sets the java.compiler property in the system properties. Defaults to jitc_ppc on PowerPC architectures and to the empty string on Intel architectures.

 

AWT_TOOLKIT

Sets the awt.toolkit property in the system properties. Defaults to com.apple.rhapsody.awt.RToolkit.

 

DYLD_LIBRARY_PATH

Prefixes the path searched by the Java virtual machine when looking up dynamically loaded libraries. The following directories are always searched in the order they are listed: .:/usr/lib:/lib:/System/Library/Frameworks/JavaVM.framework/Libraries.

 

Known Problems

• If you need to include any of the JDK header files, you will need to add the /System/Library/Frameworks/JavaVM.framework/Headers directory to the include search path. In ProjectBuilder, this is specified in the "Header Search Order" list in the "Project Inspector" panel.
  
  
• Some Java applets and applications require large amounts of memory. You can specify the amount of memory allocated for the Java heap using the -mx option. Defaults to 16MB.