rmid starts the activation system daemon that allows objects to be registered and activated in a Java virtual machine (JVM).
rmid [options]
The rmid tool starts the activation system daemon. The activation system daemon must be started before activatable objects can be either registered with the activation system or activated in a JVM. See the RMI Specification and Activation tutorials for details on how to write programs that use activatable remote objects.
The daemon can be started by executing the rmid
command, and specifying a security policy file, as follows:
rmid -J-Djava.security.policy=rmid.policy
Note: When running Sun's implementation of
rmid, by default you will need to specify a security
policy file so that rmid can verify whether or not the
information in each ActivationGroupDesc is allowed to
be used to launch a JVM for an activation group. Specifically, the
command and options specified by the
CommandEnvironment and any Properties
passed to an ActivationGroupDesc's constructor must
now be explicitly allowed in the security
policy file for rmid. The value of the sun.rmi.activation.execPolicy
property dictates the policy that rmid uses to
determine whether or not the information in an
ActivationGroupDesc may be used to launch a JVM for an
activation group.
Executing rmid by default
ActivationSystem to the name
java.rmi.activation.ActivationSystem in this internal
registry.-port option when starting up rmid. For
example,
rmid -J-Djava.security.policy=rmid.policy -port 1099
starts the activation system daemon and a registry on the
registry's default port, 1099.
rmid when
that process is created. For example, you could pass a property to
each Java virtual machine spawned by the activation system daemon:
rmid -C-Dsome.property=value
This ability to pass command-line arguments to child processes can
be useful for debugging. For example, the following command:
rmid -C-Djava.rmi.server.logCalls=true
will enable server-call logging in all child JVMs.
java
interpreter running rmid. For example, to specify that
rmid use a policy file named rmid.policy,
the -J option can be used to define the
java.security.policy property on rmid's
command line, for example:
rmid -J-Djava.security.policy=rmid.policy
rmid employs to check
commands and command-line options used to launch the JVM in which
an activation group runs. Please note that this option exists only
in Sun's implementation of the RMI activation daemon. If this
property is not specified on the command line, the result is the
same as if -J-Dsun.rmi.activation.execPolicy=default
were specified. The possible values of <policy> can be
default, <policyClassName>, or none:
The default execPolicy allows rmid to
execute commands with specific command-line options only if
rmid has been granted permission to execute those
commands and options in the security policy
file that rmid uses. Only the default activation
group implementation can be used with the default execution
policy.
rmid launches a JVM for an activation group using
the information in the group's registered activation group
descriptor, an ActivationGroupDesc. The group
descriptor specifies an optional
ActivationGroupDesc.CommandEnvironment which includes
the command to execute to start the activation group as well
as any command line options to be added to the command line.
By default, rmid uses the java command
found in java.home. The group descriptor also contains
properties overrides that are added to the command line as
options defined as:
-D<property>=<value>
The permission com.sun.rmi.rmid.ExecPermission is
used to grant rmid permission to execute a command,
specified in the group descriptor's CommandEnvironment
to launch an activation group. The permission
com.sun.rmi.rmid.ExecOptionPermission is used to allow
rmid to use command-line options, specified as
properties overrides in the group descriptor or as options in the
CommandEnvironment, when launching the activation
group.
When granting rmid permission to execute various
commands and options, the permissions ExecPermission and ExecOptionPermission need
to be granted universally (i.e., granted to all code sources).
ExecPermissionExecPermission class represents permission for
rmid to execute a specific command to launch an
activation group.
Syntax
The name of an ExecPermission is the path name
of a command to grant rmid permission to execute. A
path name that ends in "\*" indicates all the files contained in
that directory (where "\" is the file-separator character,
File.separatorChar). A path name that ends with "\-"
indicates all files and subdirectories contained in that directory
(recursively). A path name consisting of the special token
"<<ALL FILES>>" matches any file.
Note: A path name consisting of a single "*" indicates all the files in the current directory, while a path name consisting of a single "-" indicates all the files in the current directory and (recursively) all files and subdirectories contained in the current directory.
ExecOptionPermissionExecOptionPermission class represents
permission for rmid to use a specific command-line
option when launching an activation group. The name
of an ExecOptionPermission is the value of a command
line option.
Syntax
Options support a limited wildcard scheme. An asterisk signifies a
wildcard match, and it may appear as the option name itself (i.e.,
it matches any option), or an asterisk may appear at the end of the
option name only if the asterisk follows either a "." or "=".
For example: "*" or "-Dfoo.*" or "-Da.b.c=*" is valid, "*foo" or "-Da*b" or "ab*" is not.
rmidrmid permission to execute various
commands and options, the permissions ExecPermission
and ExecOptionPermission need to be granted
universally (i.e., granted to all code sources). It is safe to
grant these permissions universally because only rmid
checks these permissions.
An example policy file that grants various execute permissions
to rmid is:
grant {
permission com.sun.rmi.rmid.ExecPermission
"c:\\files\\apps\\java\\jdk1.7.0\\win\\bin\\java";
permission com.sun.rmi.rmid.ExecPermission
"c:\\files\\apps\\rmidcmds\\*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.policy=c:\\files\\policies\\group.policy";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.debug=*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Dsun.rmi.*";
};
The first permission granted allow rmid to execute the
1.7.0 version of the java command, specified by its
explicit path name. Note that by default, the version of the
java command found in java.home is used
(the same one that rmid uses), and does not need to be
specified in the policy file. The second permission allows
rmid to execute any command in the directory
c:\files\apps\rmidcmds\.
The third permission granted, an
ExecOptionPermission, allows rmid to
launch an activation group that defines the security policy file to
be c:\files\policies\group.policy. The next permission
allows the java.security.debug property to be used by
an activation group. The last permission allows any property in the
sun.rmi property name hierarchy to be used by
activation groups.
To start rmid with a policy file, the
java.security.policy property needs to be specified on
rmid's command line, for example:
rmid -J-Djava.security.policy=rmid.policy
If the default behavior is not flexible enough, an administrator
can provide, when starting rmid, the name of a class
whose checkExecCommand method is executed in order to
check commands to be executed by rmid.
The policyClassName specifies a public class with a
public, no-argument constructor and an implementation of the
following checkExecCommand method:
public void checkExecCommand(ActivationGroupDesc desc,
String[] command)
throws SecurityException;
Before launching an activation group, rmid calls the
policy's checkExecCommand method, passing it the
activation group descriptor and an array containing the complete
command to launch the activation group. If the
checkExecCommand throws a
SecurityException, rmid will not launch
the activation group and an ActivationException will
be thrown to the caller attempting to activate the object.
If the sun.rmi.activation.execPolicy property value
is "none", then rmid will not perform any validation
of commands to launch activation groups.
log,
in the directory in which the rmid command was
executed.rmid's registry uses. The
activation system daemon binds the ActivationSystem,
with the name java.rmi.activation.ActivationSystem, in
this registry. Thus, the ActivationSystem on the local
machine can be obtained using the following
Naming.lookup method call:
import java.rmi.*;
import java.rmi.activation.*;
ActivationSystem system; system = (ActivationSystem)
Naming.lookup("//:port/java.rmi.activation.ActivationSystem");
rmid, for a port
specified by the -port option. If no port is
specified, it will stop the rmid running on port
1098.
.;C:\usr\local\java\classes
