Java 1.1.1 for OS/2 is the port of Sun's Java version 1.1.1 programming environment to IBM's OS/2 Warp operating system. This file describes the use of the Runtime component of Java 1.1.1 for OS/2.
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 Java 1.1.1 for OS/2 files.
The installation of the Runtime component makes the following changes to the PATH and LIBPATH statements in CONFIG.SYS:
PATH includes x:\java11\bin; LIBPATH includes x:\java11\dll;
where x is the drive on which 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:
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 but is no longer needed.
The .class file is created by the Java Compiler, JAVAC. The Java Compiler is shipped as part of the Java Toolkit component and is only necessary if you will be writing Java programs yourself.
If you enter JAVA without any options, 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:
applet tictactoe.html
If you enter APPLET without any options, 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. The "Unable to load DLL" warning message can be ignored; this is just an indication that you are running your Java application or applet without the JIT.
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 Java 1.1.1 for OS/2 which 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:
SET JAVA_COMPILER=xyz
java -Djava.compiler=xyz hello
When you run your Java application or applet with the JIT disabled, you see an "Unable to load DLL" warning message with the name of the non-existent DLL you specified. You can ignore this message; it is just an indication that you are running your Java application or applet without the JIT.
As per JavaSoft's specification, Java 1.1.1 for OS/2 supports only English font sets. To draw in a DBCS language on AWT components, Java 1.1.1 for OS/2 uses the DBCS font association function. Due to a restriction in the DBCS font association function, Java 1.1.1 for OS/2 cannot draw any single-byte-width fonts in DBCS languages on AWT components.
To keep abreast of the current happenings with Java and IBM, visit the IBM Java Home Page or Sun's Web site at http://java.sun.com/.