rmid(1) JDK Commands rmid(1)
NAME
rmid - start the activation system daemon that enables objects to be
registered and activated in a Java Virtual Machine (JVM)
SYNOPSIS
rmid [options]
options
This represent the command-line options for the rmid command.
See Options for rmid.
DESCRIPTION
Deprecation Notice: The rmid tool and the RMI Activation mechanism have
been deprecated and may be removed from a future version of the plat-
form. See JEP 385 [https://openjdk.java.net/jeps/385] for further in-
formation.
The rmid command starts the activation system daemon. The activation
system daemon must be started before objects that can be activated are
either registered with the activation system or activated in a JVM.
Start the daemon by executing the rmid command and specifying a securi-
ty policy file, as follows:
rmid -J-Djava.security.policy=rmid.policy
When you run Oracle's implementation of the rmid command, by default
you must specify a security policy file so that the rmid command can
verify whether or not the information in each ActivationGroupDesc is
allowed to be used to start a JVM for an activation group. Specifical-
ly, the command and options specified by the CommandEnvironment and any
properties passed to an ActivationGroupDesc constructor must now be ex-
plicitly allowed in the security policy file for the rmid command. The
value of the sun.rmi.activation.execPolicy property dictates the policy
that the rmid command uses to determine whether or not the information
in an ActivationGroupDesc can be used to start a JVM for an activation
group. For more information see the description of the -J-Dsun.rmi.ac-
tivation.execPolicy=policy option.
Executing the rmid command starts the Activator and an internal reg-
istry on the default port 1098 and binds an ActivationSystem to the
name java.rmi.activation.ActivationSystem in this internal registry.
To specify an alternate port for the registry, you must specify the
-port option when you execute the rmid command. For example, the fol-
lowing command starts the activation system daemon and a registry on
the registry's default port, 1099.
rmid -J-Djava.security.policy=rmid.policy -port 1099
START RMID ON DEMAND (LINUX ONLY)
An alternative to starting rmid from the command line is to configure
xinetd (Linux) to start rmid on demand.
When RMID starts, it attempts to obtain an inherited channel (inherited
from inetd/xinetd) by calling the System.inheritedChannel method. If
the inherited channel is null or not an instance of java.nio.chan-
nels.ServerSocketChannel, then RMID assumes that it wasn't started by
inetd/xinetd, and it starts as previously described.
If the inherited channel is a ServerSocketChannel instance, then RMID
uses the java.net.ServerSocket obtained from the ServerSocketChannel as
the server socket that accepts requests for the remote objects it ex-
ports: The registry in which the java.rmi.activation.ActivationSystem
is bound and the java.rmi.activation.Activator remote object. In this
mode, RMID behaves the same as when it is started from the command
line, except in the following cases:
o Output printed to System.err is redirected to a file. This file is
located in the directory specified by the java.io.tmpdir system prop-
erty (typically /var/tmp or /tmp) with the prefix rmid-err and the
suffix tmp.
o The -port option isn't allowed. If this option is specified, then
RMID exits with an error message.
o The -log option is required. If this option isn't specified, then
RMID exits with an error message
OPTIONS FOR RMID
-Coption
Specifies an option that's passed as a command-line argument to
each child process (activation group) of the rmid command when
that process is created. For example, you could pass a property
to each 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
enables server-call logging in all child JVMs.
rmid -C-Djava.rmi.server.logCalls=true
-Joption
Specifies an option that's passed to the Java interpreter run-
ning RMID command. For example, to specify that the rmid com-
mand use a policy file named rmid.policy, the -J option can be
used to define the java.security.policy property on the rmid
command line, for example:
rmid -J-Djava.security.policy-rmid.policy
-J-Dsun.rmi.activation.execPolicy=policy
Specifies the policy that the RMID command employs to check com-
mands and command-line options used to start the JVM in which an
activation group runs. This option exists only in Oracle's im-
plementation of the Java RMI activation daemon. If this proper-
ty isn't specified on the command line, then the result is the
same as though -J-Dsun.rmi.activation.execPolicy=default were
specified.
The possible values of policy can be default, policyClassName,
or none.
o default
The default or unspecified value execPolicy allows the rmid
command to execute commands with specific command-line options
only when the rmid command was granted permission to execute
those commands and options in the security policy file that
the rmid command uses. Only the default activation group im-
plementation can be used with the default execution policy.
The rmid command starts a JVM for an activation group with the
information in the group's registered activation group de-
scriptor, ActivationGroupDesc. The group descriptor specifies
an optional ActivationGroupDesc.CommandEnvironment that in-
cludes the command to execute to start the activation group
and any command-line options to be added to the command line.
By default, the rmid command uses the java command found in
java.home. The group descriptor also contains properties
overrides that are added to the command line as options de-
fined as: -Dproperty=value. The com.sun.rmi.rmid.ExecPermis-
sion permission grants the rmid command permission to execute
a command that's specified in the group descriptor's Comman-
dEnvironment to start an activation group. The
com.sun.rmi.rmid.ExecOptionPermission permission enables the
rmid command to use command-line options, specified as proper-
ties overrides in the group descriptor or as options in the
CommandEnvironment when starting the activation group. When
granting the rmid command permission to execute various com-
mands and options, the permissions ExecPermission and ExecOp-
tionPermission must be granted to all code sources.
ExecPermission class: Represents permission for the rmid com-
mand to execute a specific command to start an activation
group.
ExecPermission syntax: The name of ExecPermission is the path
name of a command to grant the rmid command permission to exe-
cute.
A path name that ends in a slash (/) and an asterisk (*) indi-
cates that all of the files are contained in that directory
where the slash is the file-separator character, File.separa-
torChar.
A path name that ends in a slash (/) and a minus sign (-) in-
dicates that all files and subdirectories are contained in
that directory (recursively).
A path name that consists of the special token <<ALL FILES>>
matches any file.
A path name that consists of an asterisk (*) indicates that
all the files are in the current directory.
A path name that consists of a minus sign (-) indicates that
all the files are in the current directory and (recursively)
all files and subdirectories are contained in the current di-
rectory.
ExecOptionPermission class: Represents permission for the rmid
command to use a specific command-line option when starting an
activation group. The name of ExecOptionPermission is the
value of a command-line option.
ExecOptionPermission syntax: Options support a limited wild
card scheme. An asterisk signifies a wild card match, and it
can appear as the option name itself (matches any option), or
an asterisk (*) can appear at the end of the option name only
when the asterisk (*) follows a dot (.) or an equals sign (=).
For example: * or -Dmydir.* or -Da.b.c=* is valid, but *mydir
or -Da*b or ab* isn't valid.
Policy file for rmid
When you grant the rmid command permission to execute various
commands and options, the permissions ExecPermission and Exe-
cOptionPermission must be granted to all code sources (univer-
sally). It is safe to grant these permissions universally be-
cause only the rmid command checks these permissions.
An example policy file that grants various execute permissions
to the rmid command is:
o Linux:
grant {
permission com.sun.rmi.rmid.ExecPermission
"/files/apps/java/jdk1.7.0/linux/bin/java";
permission com.sun.rmi.rmid.ExecPermission
"/files/apps/rmidcmds/*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.policy=/files/policies/group.policy";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.debug=*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Dsun.rmi.*";
};
o Windows:
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 allows the rmid command to exe-
cute the 1.7.0 release of the java command, specified by its
explicit path name. By default, the version of the java com-
mand found in java.home is used (the same one that the rmid
command uses), and doesn't need to be specified in the policy
file. The second permission allows the rmid command to exe-
cute any command in either the directory /files/apps/rmidcmds
(Linux and macOS) or the directory c:\files\apps\rmidcmds\
(Windows).
The third permission granted, ExecOptionPermission, allows the
rmid command to start an activation group that defines the se-
curity policy file to be either /files/policies/group.policy
(Linux) or c:\files\policies\group.policy (Windows). The next
permission allows the java.security.debug property to be used
by an activation group. The last permission allows any prop-
erty in the sun.rmi property name hierarchy to be used by ac-
tivation groups.
To start the rmid command with a policy file, the java.securi-
ty.policy property needs to be specified on the rmid command
line, for example:
rmid -J-Djava.security.policy=rmid.policy.
o policyClassName
If the default behavior isn't flexible enough, then an admin-
istrator can provide, when starting the rmid command, the name
of a class whose checkExecCommand method is executed to check
commands to be executed by the rmid command.
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 starting an activation group, the rmid command calls
the policy's checkExecCommand method and passes to it the ac-
tivation group descriptor and an array that contains the com-
plete command to start the activation group. If the checkEx-
ecCommand throws a SecurityException, then the rmid command
doesn't start the activation group and an ActivationException
is thrown to the caller attempting to activate the object.
o none
If the sun.rmi.activation.execPolicy property value is none,
then the rmid command doesn't perform any validation of com-
mands to start activation groups.
-log dir
Specifies the name of the directory that the activation system
daemon uses to write its database and associated information.
The log directory defaults to creating a log, in the directory
in which the rmid command was executed.
-port port
Specifies the port that the registry uses. The activation sys-
tem daemon binds ActivationSystem, with the name java.rmi.acti-
vation.ActivationSystem, in this registry. The ActivationSystem
on the local machine can be obtained using the following Nam-
ing.lookup method call:
import java.rmi.*;
import java.rmi.activation.*;
ActivationSystem system; system = (ActivationSystem)
Naming.lookup("//:port/java.rmi.activation.ActivationSystem");
-stop Stops the current invocation of the rmid command for a port
specified by the -port option. If no port is specified, then
this option stops the rmid invocation running on port 1098.
JDK 15 2020 rmid(1)
openjdk 15.0.2 - Generated Thu Feb 25 15:31:17 CST 2021