JAVAVM(1) BSD General Commands Manual JAVAVM(1)NAMEjavavm — convenient wrapper for switching Java VMs
SYNOPSISjavavm [arguments ...]
DESCRIPTION
The Java VM wrapper provides a convenient system for switching between
different Java VMs. It also provides symbolic links in /usr/local/bin to
allow the use of the Java executables without having to add the specific
Java VM executable directories to the PATH environment variable.
The javavm utility itself is currently a synonym for “java”. However,
this behaviour is deprecated and is provided only for compatibility with
the previous version of javavm. This functionality may be removed in a
future version and should not be relied upon.
By default, javavm will select the most “native” and up to date version
of the Java VM when a given symbolic link is used, invoking and passing
the arguments to the matching executable within the chosen Java VM. The
choice of Java VM may also be influenced by using environment variables
to constrain the version, vendor and operating system of the Java VM.
This selection process is usually achieved through the use of
/usr/ports/Mk/bsd.java.mk. However, if this is not present then javavm
will use its own internal selection process which is designed to behave
almost identically.
ENVIRONMENT
JAVA_HOME
The presence of this variable in the environment when executing
javavm will override all other considerations regarding the Java
VM to be used and the Java VM located at ${JAVA_HOME}/bin/java
will be used.
This variable is set by javavm when executing the actual Java VM
and will be available to it and all of its child processes.
JAVA_OS
A space delimited list of operating systems. The selected Java
VM must have been created for one of the operating systems in the
list.
Currently allowed operating system values are ‘native’ and
‘linux’.
JAVA_VENDOR
A space delimited list of Java VM vendors. The selected Java VM
must have been released by one of the vendors in the list.
Currently allowed vendors are ‘bsdjava’, ‘freebsd’, ‘openjdk’ and
‘sun’.
JAVA_VERSION
A space delimited list of versions of the Java VM that may be
used. By appending a ‘+’ to a version, any Java VM with a ver‐
sion greater than or equal to the given version will be used.
Currently allowed versions are ‘1.5’, ‘1.5+’, ‘1.6’, ‘1.6+’,
‘1.7’ and ‘1.7+’.
JAVAVM_OPTS
The contents of this environment variable will be passed to the
invoked Java VM as options. For more information on environment
variables which can be used to set options see
/usr/local/etc/javavm_opts.conf.dist.
JAVAVM_FALLBACK_ONLY
If this variable is set then instead of selecting the Java VM
based on /usr/ports/Mk/bsd.java.mk only the internal selection
process is used. This may be useful to achieve consistent
results for Java VM selection across multiple hosts, where some
have the ports collection installed and others do not. However,
this option, when used with scripts installed by a port, may
result in Java VM selection inconsistent with that intended by
the script author.
JAVAVM_DRYRUN
When this variable is set, no Java VM is invoked. Instead, the
Java VM wrapper prints out the following information:
JAVA_HOME
The value of the JAVA_HOME environment variable which the
Java VM wrapper would have set before invoking the Java
VM.
JAVAVM_CONF
The Java VM wrapper configuration file being used.
JAVAVM_OPTS_CONF
The Java VM wrapper option configuration file being used.
JAVAVM_PROG
The Java VM that would have been invoked.
JAVAVM_OPTS
The options that would have been passed to the invoked
Java VM. It is important to note that this variable may
not be the same as the JAVAVM_OPTS environment variable
due to processing of the Java VM wrapper option configu‐
ration file.
JAVAVM_COMMAND
The full command line that would have been used to invoke
the Java VM.
FILES
/usr/local/etc/javavms
The location of the Java VM wrapper configuration file.
/usr/local/etc/javavm_opts.conf
The location of the Java VM wrapper option configuration file.
/usr/ports/Mk/bsd.java.mk
The file usually used, along with make, to select the Java VM to
be used.
EXAMPLES
/usr/local/bin/java
Execute the most up to date and “native” Java VM registered with
javavm.
JAVA_VERSION=1.5+ /usr/local/bin/javac MyClass.java
Compile MyClass.java with a registered Java VM's javac that is at
least version 1.5.
JAVA_OS=native /usr/local/bin/java -jar MyApp.jar
Execute MyApp with the most up to date native Java VM that is
registered with javavm. This is necessary if MyApp uses JNI, for
instance.
JAVA_VERSION="1.5 1.7" /usr/local/bin/java -jar MyApp.jar
Execute MyApp with either a Java VM that is either version 1.5 or
version 1.7.
JAVAVM_DRYRUN=yes /usr/local/bin/java
Don't invoke the Java VM, but print out information about what
would have been done. This could be used in a script to deter‐
mine the JAVA_HOME that the Java VM wrapper will use, for
instance:
JAVA_HOME=`env JAVAVM_DRYRUN=yes /usr/local/bin/java | grep
'^JAVA_HOME' | cut -c11-`
SEE ALSOcheckvms(1), make(1), manvm(1), registervm(1), unregistervm(1),
javavm_opts.conf(5), javavms(5)BUGS
The internal selection procedure of javavm is not fully identical to that
used when /usr/ports/Mk/bsd.java.mk is present. In particular, javavm
does not respect environment variables such as JAVA_PREFERRED_PORTS which
is used by /usr/ports/Mk/bsd.java.mk and will not use the values of such
variables if they are set up as make variables in /etc/make.conf, for
example.
BSD February 24, 2005 BSD
