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README
The Java(tm) Runtime Environment
JRE 1.1.6
-----------------------------------------------------------------------
CONTENTS
Overview of the Java Runtime Environment
- Introduction
- The Java Runtime Interpreter
- Required vs. Optional Files
- Win 32 Files
- Required Files
- Optional Files
- Solaris Files
- Required Files
- Optional Files
Bundling and Running the Java Runtime
- Bundling the Java Runtime
- Java Runtime Example
- Runtime Documentation
=======================================================================
Overview of the Java Runtime Environment
=======================================================================
-----------------------------------------------------------------------
Introduction
-----------------------------------------------------------------------
This is version 1.1.6 of the Java Runtime Environment, also known as
the Java Runtime, or JRE. The Java Runtime is the minimum standard
Java Platform for running Java programs. It contains the Java
Virtual Machine, Java Core Classes and supporting files.
The JRE can be invoked from the command line by using the jre tool
(see the following section). On Windows platforms, the jre tool will
ignore the CLASSPATH environment variable. For both Windows and
Solaris platforms, the -cp option is recommended to specify an
application's class path.
Although this is a maintenance release, the Win32 version of the Java
Runtime Environment includes a significant performance enhancement. A
production-quality version of Symantec JIT bytecode compiler is
included. This is the same JIT previously packaged as an early-access
product in the Win32 Performance Pack. Because the JIT compiler is now
included in the JRE software, the Performance Pack has been
discontinued. The JIT compiler is enabled by default on the Win32
JRE. To disable the compiler, you can use the -nojit option of
the Java runtime interpreter (see following section).
The Symantec JIT compiler is copyrighted (c), 1996-1998, by Symantec
Corporation. All rights reserved.
This document uses the term "vendors" to refer to licensees,
developers, and independent software vendors (ISVs) who
license and distribute the JRE with their Java programs.
The Win32 version of JRE 1.1.6 has an installer suitable for use
by end-users. This gives software developers the option of not
bundling the JRE with their applications. Instead, they can direct
end-users to download and install the JRE themselves.
An installer is not available for Solaris versions of the JRE.
Developers should bundle the JRE and an installer with their Solaris
applications.
The JRE includes all of the non-debuggable .dll or .so files plus
the necessary classes from the JDK 1.1.6 to support a runtime-only
program. The JRE does not include any of the development tools
(such as appletviewer or javac) or classes that would pertain only
to a development system.
Vendors must follow the terms of the JRE Binary Code License agreement,
which includes these terms:
- Don't arbitrarily subset the JRE. You may omit only the
files listed below as optional. See the section entitled
Required vs. Optional Files.
- Include in your product's license the provisions called out
in the JRE Binary Code License.
Comments regarding the JRE are welcome. Please send them to
jre-comments@java.sun.com. Due to the large volume of email received
each day, JavaSoft usually cannot respond to your email personally.
The JRE is a product of Sun Microsystems, Inc.
JavaSoft is an operating company of Sun, and develops the JRE.
-----------------------------------------------------------------------
The Java Runtime Interpreter
-----------------------------------------------------------------------
The jre tool invokes the Java Runtime interpreter for executing Java
applications. The tool is available in the Win32, Solaris-Sparc, and
Solaris x86 downloads of the JRE. The syntax for the jre command is:
jre [ options ] classname <args>
The classname argument is the name of the class file to be
executed. Any arguments to be passed to the class must be placed
after the classname on the command line.
An alternative version of the tool, jrew, is available for Win32. The
jrew command is identical to jre, except that a console window is not
invoked. The syntax of the jrew command is
jrew [ options ] classname <args>
On Windows platforms, the jre tool will ignore the CLASSPATH
environment variable. For both Windows and Solaris platforms, the
-cp option is recommended to specify an application's class path.
Options for the jre and the jrew commands are as follows:
-classpath path Specifies the path that jre uses to
look up classes. Overrides the default
classpath.
-cp path Prepends the specified path to the default
classpath that jre uses to look up classes.
-help Print a usage message.
-mx x Sets the maximum size of the memory allocation
pool (the garbage collected heap) to x. The
default is 16 megabytes of memory. x must be
greater than or equal to 1000 bytes.
-ms x Sets the startup size of the memory allocation
pool (the garbage collected heap) to x. The
default is 1 megabyte of memory. x must be
greater than 1000 bytes.
-noasyncgc Turns off asynchronous garbage collection. When
activated, no garbage collection takes place
unless it is explicitly called or the program
runs out of memory.
-noclassgc Turns off garbage collection of Java classes.
By default, the Java interpreter reclaims space
for unused Java classes during garbage collection.
-nojit Don't invoke the Just In Time bytecode
compiler. The virtual machine directly
interprets bytecodes, without converting them
to native code.
-ss x The -ss option sets the maximum stack size that
can be used by C code in a thread to x. The
default units for x are bytes. The value of x
must be greater than or equal to 1000 bytes.
-oss x The -oss option sets the maximum stack size
that can be used by Java code in a thread to x.
The default units for x are bytes. The value of
x must be greater than or equal to 1000 bytes.
-v, -verbose Causes jre to print a message to stdout each
time a class file is loaded.
-verify Performs byte-code verification on the class
file. Beware, however, that java -verify does
not perform a full verification in all
situations. Any code path that is not actually
executed by the interpreter is not verified.
Therefore, java -verify cannot be relied upon to
certify class files unless all code paths in
the class file are actually run.
-verifyremote Runs the verifier on all code that is loaded
into the system via a classloader. verifyremote
is the default for the interpreter.
-noverify Turns verification off.
-verbosegc Causes the garbage collector to print out
messages whenever it frees memory.
-DpropName=value Defines a property value. propName is the name
of the property whose value you want to change
and value is the value to change it to. For
example, the command
java -Dawt.button.color=green ...
sets the value of the property awt.button.color
to "green".
-----------------------------------------------------------------------
Required vs. Optional Files
-----------------------------------------------------------------------
Licensees must follow the terms of the accompanying LICENSE.
The files that make up the JRE are divided into two categories:
required and optional. To paraphrase that license, files that
are marked "optional" here do not need to be included in
redistributions of the JRE with the licensee's program. Most of the
optional files provide localization support for languages.
The term "required" means licensees who distribute the runtime
must include those files with their program, whether or not their
program ever uses those files. Those files are a required part of
the Java Platform.
The JRE includes the bin and lib directories which both must
reside in the same directory. We call this directory <runtime-dir>.
In the following lists, all paths are relative to the <runtime-dir>
directory (which is originally "jre1.1.6").
-----------------------------------------------------------------------
Win32 Files
-----------------------------------------------------------------------
Two versions of JRE 1.1.6 for Win32 are available. One version contains
files for internationalization support. The version with
internationalization support contains all the files listed below under
both the REQUIRED FILES and OPTIONAL FILES subsections. A smaller
version of the Win32 JRE is available that does not contain those
optional files that provide internationalization support.
Required Files --------------------------------------------------------
The Win32 bin directory contains the executables and native libraries:
bin\jre.exe Java runtime executable
bin\jrew.exe Java runtime executable, no console window
bin\rmiregistry.exe rmiregistry executable
bin\javai.dll Java runtime native code library
bin\JdbcOdbc.dll native code support for sun.jdbc
bin\jpeg.dll native code support for sun.jpeg
bin\math.dll native code support for java.math
bin\mmedia.dll native code support for sun.audio
bin\net.dll native code support for java.net
bin\sysresource.dll native code support for sun.net.www.protocol
bin\winawt.dll native code support for sun.awt
bin\zip.dll native code support for java.util.zip
bin\msvcrt.dll native code C runtime library
The Win32 lib directory contains the classes and property files:
lib\rt.jar Java runtime core classes
lib\content-types.properties MIME-type properties
lib\awt.properties properties for key events for java.awt
lib\font.properties Win32 font properties for java.awt
lib\serialver.properties serialization properties
lib\security\java.security properties for java.security
Optional Files --------------------------------------------------------
The following files are optional:
lib\i18n.jar I18N character conversion classes from
sun.io
lib\font.properties.ar AWT font properties for Arabic locale
lib\font.properties.iw AWT font properties for Hebrew locale
lib\font.properties.ja AWT font properties for Japanese locale
lib\font.properties.ko AWT font properties for Korean locale
lib\font.properties.ru AWT font properties for Russian locale
lib\font.properties.th AWT font properties for Thai locale
lib\font.properties.zh_TW AWT font properties for Traditional
Chinese locale
lib\font.properties.zh AWT font properties for Simplified
Chinese locale
bin\symcjit.dll JIT compiler
-----------------------------------------------------------------------
Solaris Files
-----------------------------------------------------------------------
You can optionally install the Solaris Native Threads Pack 1.1.6 in the
Solaris versions of the JRE. (The Native Threads Pack is available for
download from the JDK download site.) With the native threads pack
installed, you can use either the native threads files or the default
set of threads files (called "green threads") when running programs
with the JRE. If you redistribute the JRE, you must include either the
entire set of default green threads files, or the entire set of native
threads files, or both entire sets.
Required Files --------------------------------------------------------
The directory <sys> varies depending on the hardware architecture
(either "sparc" or "i386") and threads implementation (either
"green_threads" or "native_threads"). To indicate the green threads
implementation on Solaris-SPARC, for example, <sys> would stand for
"sparc/green_threads". If the Solaris native threads pack is installed
in the Solaris-x86 JRE, for another example, <sys> could stand for
"i386/native_threads". When redistributing the JRE, you must include
either the entire set of default green threads files, or the entire set
of native threads files, or both entire sets.
The Solaris bin directory contains the shell scripts and executables:
bin/jre Java runtime shell script wrapper
bin/rmiregistry rmiregistry shell script wrapper
bin/<sys>/jre Java runtime executable
bin/<sys>/rmiregistry rmiregistry executable
The Solaris lib directory and its subdirectories contain the
classes, properties files and native libraries:
lib/rt.jar Java runtime core classes
lib/content-types.properties MIME-type properties
lib/awt.properties properties for key events for java.awt
lib/font.properties Solaris font properties for java.awt
lib/serialver.properties properties for servialver
lib/security/java.security properties for java.security
lib/<sys>/libjava.so Java runtime library
lib/<sys>/libnet.so native code support for java.net
lib/<sys>/libmath.so native code support for java.math
lib/<sys>/libmmedia.so native code support for sun.audio
lib/<sys>/libawt.so native code support for sun.awt
lib/<sys>/libjpeg.so native code support for sun.jpeg
lib/<sys>/libJdbcOdbc.so native code support for sun.jdbc
lib/<sys>/libsysresource.so native code support for sun.net
lib/<sys>/libzip.so native code support for java.util.zip
Optional Files --------------------------------------------------------
The following files are optional.
lib/i18n.jar I18N character conversion classes from sun.io
lib/font.properties.cs AWT font properties for Czech locale
lib/font.properties.pl AWT font properties for Polish locale
lib/font.properties.hu AWT font properties for Hungarian locale
lib/font.properties.lt AWT font properties for Lithuanian locale
lib/font.properties.lv AWT font properties for Latvian locale
lib/font.properties.el AWT font properties for Greek locale
lib/font.properties.tr AWT font properties for Turkish locale
lib/font.properties.ja AWT font properties for Japanese locale
lib/psfont.properties.ja AWT psfont properties for Japanese locale
lib/font.properties.ru AWT font properties for Russian locale
lib/font.properties.ko AWT font properties for Korean locale
lib/font.properties.zh_EUC_CN AWT font properites for Simplified
Chinese locale
lib/font.properties.zh_TW_Big5 AWT font properties for Traditional
Chinese locale
lib/font.properties.zh_TW_EUC_TW Alternative AWT font properties for
Traditional Chinese locale
lib/<sys>/libXm.so Symbolic link to Motif runtime library
lib/<sys>/libXm.so.3 Motif runtime library
libXm.so.3 is present in Solaris 2.5 and later, so is needed only if
your program is to run on Solaris 2.4 or earlier.
=======================================================================
Bundling and Running the Java Runtime
=======================================================================
-----------------------------------------------------------------------
Bundling the Java Runtime
-----------------------------------------------------------------------
This release of the JRE for Win32 comes with its own installer that
makes is suitable for downloading by end users. Java application
developers have the option of not bundling the JRE with their software.
Instead, they can direct end-users to download and install the JRE
themselves.
Solaris versions of the JRE do not have an installer. Software
developers should bundle the JRE and installer with their Solaris
software.
When bundling the JRE with application software on Solaris, the
following points should be considered:
1) It is suggested that the JRE be installed in its own subdirectory
(referred to below as <runtime-dir>). Include all the the required
files listed above in the bin and lib subdirectories of
<runtime-dir>, following the same directory hierarchy and
relative placement of files. The internationalization files
marked optional can be included for language localization support.
2) It is suggested that all application-specific classes be placed
in a directory other than <runtime-dir>. Application-specific
classes may be individual .class files, .jar files, or .zip
files.
An example directory structure might look like the following:
<app-dir>
________________|___________
| | |
bin lib <runtime-dir>
| | ________|________
app.jar | |
bin lib
| |
3) If native code support is required, then the native library must be
located in LD_LIBRARY_PATH on Solaris or the executable search PATH
on Win32. The best way to do this is to install the native libraries
in either <app-dir>/lib/<sys> on Solaris or <app-dir>\bin
on Win32. LD_LIBRARY_PATH (on Solaris) or PATH (on Win32) should
then be set to include these directories.
4) The application can be invoked by using the jre command-line tool,
using the -cp option to specify the application's class path. In
the example directory tree above, for example, the command might
look like this:
<app-dir>/<runtime-dir>/bin/jre -cp <app-dir>/lib/app.jar <classname>
Information on the jre command-line tool can be found in the
JRE 1.1.6 CHANGES file and on the JavaSoft web site at
http://java.sun.com/products/jdk1.1/docs/tooldocs/solaris/jre.html
and
http://java.sun.com/products/jdk1.1/docs/tooldocs/win32/jre.html
Source code for the jre tool can be found in the Windows JDK 1.1.6
directory tree in the jdk1.1.6\demo\jre\win32 folder. For the
Solaris JDK 1.1.6, jre source code files can be found in the
jdk1.1.6/demo/jre/solaris directory.
For more information that might be relevant to installing and running
the JRE, refer to the JDK installation instructions:
http://java.sun.com/products/jdk/1.1/installation-win32-x86.html
http://java.sun.com/products/jdk/1.1/installation-solaris2.html
-----------------------------------------------------------------------
Java Runtime Example
-----------------------------------------------------------------------
The following web page has a Hello World example that you can download
demonstrating how to create a simple Java application that runs on,
and is bundled with, the Java Runtime Environment.
http://java.sun.com/products/jdk/1.1/jre/example/
This example shows how to make a simple, seamless transition
from developing an application with the JDK, to deploying it with
the more-lightweight JRE.
-----------------------------------------------------------------------
Runtime Documentation
-----------------------------------------------------------------------
Runtime documentation is any documentation that an end-user might
need after they have installed a Java program that runs on the JRE.
We supply the following runtime documentation:
- Each property file contains comments that describe what the
file is useful for and how to modify it.
- awt.properties file - KeyEvent uses it to print out properties of
key events, usually for debugging purposes. This might be used
by a GUI debugger that needs to print out events.
- fontprop.html file has a web page describing how to add
fonts to the runtime. This document is part of the
JDK documentation, and is located both in the JDK documentation
download bundle and at the JavaSoft website:
http://java.sun.com/products/jdk/1.1/docs/guide/intl/fontprop.html
-----------------------------------------------------------------------
Copyright ⌐ 1997, 1998 Sun Microsystems, Inc.
901 San Antonio Rd., Palo Alto, CA 94303 USA.
All rights reserved.