'\" t
.\" @(#)java.1 1.14 99/02/22 SMI;
.\" Copyright 1999 Sun Microsystems, Inc. All rights reserved.
.\" Copyright 1999 Sun Microsystems, Inc. Tous droits réservés.
.\" 
'\"macro stdmacro
.TH java 1 "22 Feb 1999"
.SH NAME
java \- Java interpreter
.SH SYNOPSIS
.LP
.B java 
[ 
.I threads-flag 
] [ 
.IB options 
] 
.I class 
[ 
.I argument ... 
]
.LP
.B java 
[ 
.I threads-flag 
] [ 
.I options 
] 
.BI -jar " file.jar"
.if n .ti +5n
[ 
.I argument ... 
]
.LP
.B oldjava 
[ 
.I threads-flag 
] [ 
.I options 
] 
.I class 
[ 
.I argument ... 
]
.SH  PARAMETERS
Options may be in any order.  For a discussion of
parameters which apply to a specific option, see
.B OPTIONS
below.
.TP 15
.I threads-flag
.B green
or
.BI native .
See Solaris Multithreading Options.
.TP 15
.I options
Command-line options.
See
.B OPTIONS
below.
.TP
.I class
Name of the class to be invoked.
.TP
.I file.jar
Name of the jar 
file to be invoked. Used only with the 
.B \-jar
option.
.SH DESCRIPTION
.IX "Java interpreter" "" "Java interpreter \(em \fLjava\fP"
.IX "java" "" "\fLjava\fP \(em Java interpreter"
.LP
The 
.B java 
tool launches a Java application. It does this by
starting a Java runtime environment, loading a specified class,
and invoking that class's 
.B main 
method. The method must have the
following signature:
.LP
.ft 3
.nf
   public static void main(String args[])
.fi
.ft 1
.LP
The method must be declared 
.B public 
and 
.BR static , 
it must not
return any value, and it must accept a 
.B String 
array as a parameter.
By default, the first non-option argument is the name of the class
to be invoked. A fully-qualified class name should be used. If the
.B \-jar
option is specified, the first non-option argument is the
name of a JAR archive containing class and resource files for the
application, with the startup class indicated by the Main-Class
manifest header.
.LP
The Java runtime searches for the startup class, and other classes
used, in three sets of locations: the bootstrap class path, the
installed extensions, and the user class path.
.LP
Non-option arguments after the class name or JAR file name are
passed to the main function.
.LP
.SS Java and Oldjava
.IX "java" "Java and Oldjava" "\fLjava\fP \(em Java interpreter"
.LP
On Solaris systems, the java launcher tool comes in two
variations: java, which implements all 1.2 features; and
.BR oldjava ,
a limited-feature launcher tool, which supports programming
techniques that are incompatible with some 1.2 features. These are
the differences between
.B java 
and
.BR oldjava :
.TP 2
\(bu
The
.B oldjava 
launcher does not support the extension
mechanism, though it can, of course, use extension packages
as class and resource archives.
.TP 2
\(bu
The
.B oldjava 
launcher uses the bootstrap class loader for all
classes, while the 
.B java 
launcher uses the bootstrap class
loader only for bootstrap classes.
.TP 2
\(bu
With
.BR java , 
the 
.B \-classpath
and 
.B \-cp
options specify a search
path for user classes, and cannot be used to specify
locations for bootstrap classes. With
.B oldjava 
the 
.B \-classpath
and 
.B \-cp
options specify locations for all classes, including
bootstrap classes.
.RS 2
.LP
Note that
.B java 
and 
.B oldjava 
do not differ in their use of the
.SB CLASSPATH 
environment variable. Unless overridden by
.B \-classpath
or 
.BR \-cp , 
.SB CLASSPATH 
always specifies the location of
user classes, but says nothing about the bootstrap classes.
.RE
.TP 2
\(bu
The
.B oldjava 
launcher supports all the 1.2 security features.
With
.BR oldjava , 
however, classes loaded from the class path
will not have a protection domain and will therefore have all
permissions which is true only for bootstrap classes with the
.B java 
launcher.
.LP
This command using
.B oldjava
.LP
   \f3example% oldjava -classpath \fP\f2path\fP ...
.fi
.ft 1
.LP
is equivalent to this command using
.B java
.LP
.nf
   \f3example% java -Xbootclasspath:\fP\f2path\fP\f3 -Djava.ext.dirs= ...\fP
.fi
.ft 1
.LP
where in both cases <
.I path
> contains the file 
.BR rt.jar . 
(See the
JDK File Structure
document for a description of 
.B rt.jar 
and
its location in the JDK software.)
.LP
.SS  The JIT
.IX "java" "The JIT" "\fLjava\fP \(em Java interpreter"
.LP
The default behavior of the launcher is to execute bytecodes using
a Just In Time compiler, or JIT. 
The default compiler is located at
.BR jre/lib/sparc/libsunwjit.so .
When a class is loaded, the JIT
translates the class bytecodes into native machine code. Using a
JIT causes a slight delay after each class load, but can improve
overall program performance. In some cases, execution time will
improve by a factor of ten.
.LP
If the JIT is disabled, bytecodes are executed directly by an
interpreter. 
There are two ways to disable the JIT:
.TP 2
\(bu
Set the environment variable 
.SB JAVA_COMPILER to
.BR NONE , 
the
.BR setenv (1)
command.
.LP
.RS 2
.ft 3
.nf
example% setenv JAVA_COMPILER NONE
.fi
.ft 1
.RE
.TP 2
\(bu
Use the
.B \-D 
command-line option to set 
.BR java.compiler " to " NONE .
.LP
.RS 2
.ft 3
.nf
example% java -Djava.compiler=NONE myapp
.fi
.ft 1
.RE
.LP
Using the command-line option overrides the setting of the
.SB JAVA_COMPILER 
environment variable.
.LP
You can also use 
.SB JAVA_COMPILER 
or 
.B java.compiler 
to the specify
that an alternative JIT should be used:
.LP
.ft 3
.nf
example% setenv JAVA_COMPILER foo
.fi
.ft 1
.LP
or
.LP
.ft 3
.nf
example% java -Djava.compiler=foo myapp
.fi
.ft 1
.LP
The letters 
.B lib 
are prepended to 
.B foo 
and an 
.B .so 
filename
extension is added, so that, in this example, the virtual machine
will search for a JIT compiler named
.BR libfoo.so .
The search for the
alternative compiler is made in the 
.B jre/lib/sparc 
directory and on
the path specified by the 
.SB LD_LIBRARY_PATH 
environment variable. If
no such compiler is found, the virtual machine will default to
using the interpreter.
.SH OPTIONS
.LP
The launcher has a set of standard options that are supported on
the current runtime environment and will be supported in future
releases. An additional set of non-standard options are specific
to the current virtual machine implementation and are subject to
change in the future. Non-standard options begin with 
.BR  \-X .
.SS Standard Options
.IX "java" "Standard Options" "\fLjava\fP \(em Java interpreter"
.BI \-classpath " classpath"
.br
.BI \-cp " classpath"
.RS 15
Specify a list of directories, JAR archives, and ZIP archives
to search for class files. Class path entries are separated
by colons (:). Specifying
.B \-classpath 
or 
.B \-cp 
overrides any
setting of the 
.SB CLASSPATH 
environment variable.
.LP
Used with 
.BR java , 
the
.B \-classpath 
or 
.B \-cp 
options
only specify the
class path for user classes. Used with
.BR oldjava ,
.B \-classpath 
or 
.B \-cp 
specify the class path for both user
classes and bootstrap classes.
.LP
If 
.B \-classpath 
and 
.B \-cp 
are not used and 
.SB CLASSPATH 
is not set,
the user class path consists of the current directory (.).
.LP
For more information on class paths, see 
Setting the Class Path.
.RE
.TP 15
.B \-debug
This has been replaced by 
.BR \-Xdebug .
.TP 15
.BI \-D property=value
Set a system property value.
.TP
.B \-jar
Execute a program encapsulated in a JAR archive. The first
argument is the name of a JAR file instead of a
startup class name. 
In order for this option to work, the manifest of the
JAR file must contain a line of the form 
\f3Main-Class:\f1\f2classname\f1. 
Here, 
.I classname 
identifies the class having the
.B public static void main(String[] args) 
method that serves as
your application's starting point. See the Jar tool reference
page and the Jar trail of the Java Tutorial for information
about working with Jar files and Jar-file manifests.
When you use this option, the JAR file is the source of all
user classes, and other user class path settings are ignored.
.RS 
.LP
The 
.B oldjava 
tool does not support the 
.B \-jar
option.
.RE
.TP
.B  \-noclassgc
This has been replaced by 
.BR \-Xnoclassgc .
.TP 15
.BI \-oss n
This has been replaced by 
.BI -X0ss n .
.TP 15
.BI \-ms h
This has been replaced by 
.BI \-Xms n .
.TP 15
.BI \-mx n
This has been replaced by 
.BI \-Xmx n .
.TP 15
.BI \-ss n
This has been replaced by 
.BI \-Xss n .
.TP 15
.B \-t
This has been replaced by 
.BR \-Xt .
.TP 15
.B \-tm
This has been replaced by 
.BR \-Xtm .
.LP
.B \-verbose
.br
.BI \-verbose: class
.RS 15
Display information about each class loaded.
.RE
.TP 15
.B \-verbosegc
This has been replaced by 
.BR \-verbose:gc .
.TP 15
.B \-verbose:gc
Report on each garbage collection event.
.TP 15
.B \-verbose:jni
Report information about use of native methods and other Java
Native Interface activity.
.TP 15
.B \-version
Display version information and exit.
.LP
.B \-?
.br
.B \-help
.RS 15
Display usage information and exit.
.RE
.TP 15
.B \-X
Display information about non-standard options and exit.
.LP
.SS Non-Standard Options
.IX "java" "Non-Standard Options" "\fLjava\fP \(em Java interpreter"
.TP 15
.BI \-Xbootclasspath: bootclasspath
Specify a colon-separated list of directories, JAR
archives, and ZIP archives to search for boot class files.
These are used in place of the boot class files included in
the JDK 1.2 software.
.TP 15
.B \-Xdebug
Start with the debugger enabled. The Java interpereter prints
out a password for 
the use of
.BR jdb (1). 
Refer to 
.BR jdb (1)
description for
more details and an example.
.TP 15
.B \-Xcheck:jni
Perform additional check for Java Native Interface functions.
.TP 15
.B \-Xnoclassgc
Disable class garbage collection
.TP 15
.BI -Xms n
Specify the initial size of the memory allocation pool. This
value must greather than 1000. To multiply the value by 1000,
append the letter 
.BR k . 
To multiply the value by 1 million,
append the letter 
.BR m . 
The default value is 1m.
.TP 15
.BI \-Xmx n
Specify the maximum size of the memory allocation pool. This
value must greather than 1000. To multiply the value by 1000,
append the letter 
.BR k . 
To multiply the value by 1 million,
append the letter 
.BR m . 
The default value is 16m.
.TP 15
.BI \-Xoss n
Each Java thread has two stacks: one for Java code and
one for C code. The
.B \-Xoss
option sets the maximum stack
size that can be used by Java code in a thread to
.I n.
Every thread that is spawned during the execution of
the program passed to
.B java
has
.I n
as its Java stack
size. The default units for
.I n
are bytes
and
.I n
must be >
1000 bytes.
.sp 1n
To modify the meaning of
.IR n ,
append either the
letter 
.B k 
for kilobytes or the letter 
.B m 
for
megabytes. The default stack size is 400 kilobytes
(\f3\-Xoss400k\f1).
.TP 15
\f3\-Xrunhprof[:help][:\f2suboption\f3=\f2value\f1,...]
Enables cpu, heap, or monitor profiling. This option is
typically followed by a list of comma-separated
.IR suboption = value
pairs. Run the command
.B java -Xrunhprof:help 
to obtain a list of suboptions and their
default values.
.\" .TP 15
.\" -Xcheck:jni
.\" Perform additional check for Java Native Interface functions.
.\" .TP 15
.\" -Xverify
.\" -Xverify:all
.\" Verify that all class files obey language constraints.
.\" .TP 15
.\" -Xverify:remote
.\" Verify only remote class files. This is the default
.\" verification level.
.\" .TP 15
.\" -Xverify:none
.\" Disable class file verification.
.TP 15
.BI \-Xprof[: file ]
Enable profiling. If no file is specified, write results to
.B java.prof 
in the current directory.
.TP 15
.BI \-Xss n
Each Java thread has two stacks: one for Java code and
one for C code. The
.B \-Xss
option sets the maximum stack
size that can be used by C code in a thread to
.I n.
Every
thread that is spawned during the execution of the
program passed to
.B java
has
.I n
as its C stack size. The
default units for
.I n
are bytes
and
.I n
must be > 1000 bytes.
.sp 1n
To modify the meaning of
.IR n ,
append either the
letter 
.B k 
for kilobytes or the letter 
.B m 
for
megabytes. The default stack size is 128 kilobytes
(\f3\-Xss128k\f1).
.TP 15
.B \-Xrs
Reduce the use of operating system signals.
.TP 15
.B \-Xsqnopause
Do not pause for user interaction on 
.BR siqquit .
.TP 15
.B \-Xt
Turns on instruction tracing.
.TP 15
.B \-Xtm
Turns on method tracing.
.SH ENVIRONMENT VARIABLES
.TP 15
.SB CLASSPATH
Used to provide the system with a path to user-defined
classes.  Directories are separated by colons, for
example:
.RS 20
.sp 1n
.B .:/home/avh/classes:/usr/local/java/classes
.RE 
.br
.ne 12
.SH ATTRIBUTES
See
.BR attributes (5)
for a description of the following attributes:
.SS  java
.IX "java" "java" "\fLjava\fP \(em Java interpreter"
.sp
.TS
box;
cbp-1 | cbp-1
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
=
Availability	SUNWjvrt, SUNWjvdev
.TE
.SS  oldjava
.IX "java" "oldjava" "\fLjava\fP \(em Java interpreter"
.sp
.TS
box;
cbp-1 | cbp-1
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
=
Availability	SUNWjvdev
.TE
.SH SEE ALSO
.BR javac (1),
.BR jdb (1),
.BR javac (1),
.BR jar (1),
.BR set (1)
.LP
See (or search java.sun.com) for the following:
.TP 10
Solaris Multithreading Options @
http://java.sun.com/products/jdk/1.2/docs/tooldocs/solaris/threads.html
.TP 10
JDK File Structure @
http://java.sun.com/products/jdk/1.2/docs/tooldocs/solaris/jdkfiles.html
.TP 10
Setting the Classpath @
http://java.sun.com/products/jdk/1.2/docs/tooldocs/solaris/classpath.html
.TP 10
JAR Files @ 
http://java.sun.com/docs/books/tutorial/jar/