OS/2 Warp Developer's Kit for Java 1.1.6 is the ported version of the Sun Java Version 1.1.6 programming environment to the IBM OS/2 Warp operating system. This file describes the use of the Runtime component of OS/2 Warp Developer's Kit for Java 1.1.6.
See the README file in the \JAVA11 directory for the latest information regarding installation. This file is also in the directory where you unpacked the OS/2 Warp Developer's Kit for Java 1.1.6 files.
The installation of the Runtime component makes the following changes to the PATH and LIBPATH statements in the CONFIG.SYS file:
PATH includes x:\java11\bin; LIBPATH includes x:\java11\dll;
where x is the drive where the Java Runtime component was installed.
The Java Interpreter, JAVA, executes Java byte codes. Java byte codes reside in a file with an extension of .class.
To run the Java application hello.class, type at an OS/2 command prompt:
java hello
Note that the extension for the file should not be specified (it must be .class) and that the name is case-sensitive.
Java applications that use the Abstract Window Toolkit (AWT) can be started with the JAVA command. The JAVAPM command is provided for compatibility with prior versions of Java for OS/2 Warp but is no longer needed.
The .class file is created by the Java Compiler, JAVAC. The Java Compiler is included as part of the Java Toolkit component and is necessary only if you will be writing Java programs yourself.
If you type JAVA without any options at an OS/2 command prompt, a list of available options is displayed.
The Java Applet Viewer, APPLET, provides a quick way to run Java applets. If the HTML file specified does not contain a Java applet, no function is performed.
To run the applet contained in the file tictactoe.html, type at an OS/2 command prompt:
applet tictactoe.html
If you type APPLET without any options at an OS/2 command prompt, a list of available options is displayed in a popup window.
A number of environment variables are available to modify the behavior of the Java Runtime component:
Some drivers, such as some ThinkPad 701C drivers dated prior to October 1995, appear to support a sample rate of 8000 but then fail; they can be made to work by setting a playback sample rate of 11025.
To disable the JIT, specify the name of a non-existent DLL.
There are a number of platform-specific changes for OS/2:
start /PM applet.exe example1.htmlstdout and stderr output are redirected to the WEBLOGS directory. Specify the -nore option to stop this redirection.
A just-in-time (JIT) compiler is provided with OS/2 Warp Developer's Kit for Java 1.1.6. The JIT compiler generates machine code for frequently used byte code sequences in a Java application or applet on-the-fly during execution. The JIT is enabled by default.
You can disable the JIT to aid in the isolation of a problem with a Java application, an applet, or the compiler itself in a number of different ways. For example:
SET JAVA_COMPILER=xyz
java -Djava.compiler=xyz hello
As per the JavaSoft specification, OS/2 Warp Developer's Kit for Java 1.1.6 supports only English font sets. To draw in a DBCS language on AWT components, OS/2 Warp Developer's Kit for Java 1.1.6 uses the DBCS font association function. Because of a restriction in the DBCS font association function, OS/2 Warp Developer's Kit for Java 1.1.6 cannot draw single-byte-width fonts in DBCS languages on AWT components.
For up-to-date information about Java and IBM, visit the IBM Java Home Page or Sun's Java Web site.
Trademarks
The following are trademarks of International Business Machines Corporation in the United States, or other countries, or both:
Java is a trademark of Sun Microsystems, Inc.
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