java
Name
java -- launch a Java application
Synopsis
java [-?] [-Dproperty=value] [-classpath] [-cp] [-help] [-jar file.jar] [-version] [arguments...]Description
The java command
shall launch a Java application
by initializing a Java runtime environment,
loading the class specified on the command line,
and calling the main method of that class.
The method's declaration must be as follows.
public static void main(String args[])
By default, the first argument specified
that is not an option shall be the
fully-qualified name of the class to invoke.
This behavior may be changed by the
addition of the
-jar option,
in which case the first argument specified
that is not an option shall be
the name of a JAR file.
Any arguments specified
after the class name or JAR file name
that are not command-line options
are passed to the main function.
The Java runtime shall search for the
classes used, including the startup class,
in three locations: the bootstrap class path,
the extensions that are currently installed,
and the user class path.
Options
-? | | This option is a synonym for
-help. |
-classpath classpath | | This option shall specify
a list of locations to search for class files,
including directories, JAR files, and ZIP files.
Locations in the class path shall be delimited
by colons (:). The -classpath option
shall override
the CLASSPATH environment variable.
If the -classpath option
is not specified and
CLASSPATH is not set,
then the user class path shall simply consist of
the current directory (.). The class path element *
shall specify all files in the current directory
with the extension .jar.
or .JAR.
Example: if the only JAR files in the directory
foo
are bar.jar
and bas.JAR,
then the class path element
foo/* shall be equivalent to
bar.jar:bas.JAR.
The order of JAR files in this case shall be unspecified.
The CLASSPATH environment variable
functions in the same way. Wildcards in the class path shall be expanded before
the initialization of the Java virtual machine.
However, Java programs can examine unexpanded wildcards
if they query the environment. Example:
System.getenv("CLASSPATH"). |
-cp classpath | | This option is a synonym for
-classpath. |
-Dproperty=value | | This option shall set the value of a system property. |
-help | | This option shall display usage information
for the command, then exit. |
-jar jarfile | | This option shall specify a JAR file
containing a program to execute.
Its first argument must be the name of a JAR file
with both class and resource files.
The JAR file's manifest must contain a line
of this form:
Main-Class: classname.
The class name
classname
must specify the class containing the main function
for the application. If this option is specified,
all other user class path settings shall be ignored.
JAR files that can be specified with this option
shall also be runnable without this option
by setting their execute permissions. |
-version | | This option shall display version information
for the command, then exit. |