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* Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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*/
package java.rmi.activation;
import java.io.
IOException;
import java.io.
ObjectInputStream;
import java.io.
Serializable;
import java.rmi.
MarshalledObject;
import java.util.
Arrays;
import java.util.
Properties;
/**
* An activation group descriptor contains the information necessary to
* create/recreate an activation group in which to activate objects.
* Such a descriptor contains: <ul>
* <li> the group's class name,
* <li> the group's code location (the location of the group's class), and
* <li> a "marshalled" object that can contain group specific
* initialization data. </ul> <p>
*
* The group's class must be a concrete subclass of
* <code>ActivationGroup</code>. A subclass of
* <code>ActivationGroup</code> is created/recreated via the
* <code>ActivationGroup.createGroup</code> static method that invokes
* a special constructor that takes two arguments: <ul>
*
* <li> the group's <code>ActivationGroupID</code>, and
* <li> the group's initialization data (in a
* <code>java.rmi.MarshalledObject</code>)</ul><p>
*
* @author Ann Wollrath
* @since 1.2
* @see ActivationGroup
* @see ActivationGroupID
*/
public final class
ActivationGroupDesc implements
Serializable {
/**
* @serial The group's fully package qualified class name.
*/
private
String className;
/**
* @serial The location from where to load the group's class.
*/
private
String location;
/**
* @serial The group's initialization data.
*/
private
MarshalledObject<?>
data;
/**
* @serial The controlling options for executing the VM in
* another process.
*/
private
CommandEnvironment env;
/**
* @serial A properties map which will override those set
* by default in the subprocess environment.
*/
private
Properties props;
/** indicate compatibility with the Java 2 SDK v1.2 version of class */
private static final long
serialVersionUID = -4936225423168276595L;
/**
* Constructs a group descriptor that uses the system defaults for group
* implementation and code location. Properties specify Java
* environment overrides (which will override system properties in
* the group implementation's VM). The command
* environment can control the exact command/options used in
* starting the child VM, or can be <code>null</code> to accept
* rmid's default.
*
* <p>This constructor will create an <code>ActivationGroupDesc</code>
* with a <code>null</code> group class name, which indicates the system's
* default <code>ActivationGroup</code> implementation.
*
* @param overrides the set of properties to set when the group is
* recreated.
* @param cmd the controlling options for executing the VM in
* another process (or <code>null</code>).
* @since 1.2
*/
public
ActivationGroupDesc(
Properties overrides,
CommandEnvironment cmd)
{
this(null, null, null,
overrides,
cmd);
}
/**
* Specifies an alternate group implementation and execution
* environment to be used for the group.
*
* @param className the group's package qualified class name or
* <code>null</code>. A <code>null</code> group class name indicates
* the system's default <code>ActivationGroup</code> implementation.
* @param location the location from where to load the group's
* class
* @param data the group's initialization data contained in
* marshalled form (could contain properties, for example)
* @param overrides a properties map which will override those set
* by default in the subprocess environment (will be translated
* into <code>-D</code> options), or <code>null</code>.
* @param cmd the controlling options for executing the VM in
* another process (or <code>null</code>).
* @since 1.2
*/
public
ActivationGroupDesc(
String className,
String location,
MarshalledObject<?>
data,
Properties overrides,
CommandEnvironment cmd)
{
this.
props =
overrides;
this.
env =
cmd;
this.
data =
data;
this.
location =
location;
this.
className =
className;
}
/**
* Returns the group's class name (possibly <code>null</code>). A
* <code>null</code> group class name indicates the system's default
* <code>ActivationGroup</code> implementation.
* @return the group's class name
* @since 1.2
*/
public
String getClassName() {
return
className;
}
/**
* Returns the group's code location.
* @return the group's code location
* @since 1.2
*/
public
String getLocation() {
return
location;
}
/**
* Returns the group's initialization data.
* @return the group's initialization data
* @since 1.2
*/
public
MarshalledObject<?>
getData() {
return
data;
}
/**
* Returns the group's property-override list.
* @return the property-override list, or <code>null</code>
* @since 1.2
*/
public
Properties getPropertyOverrides() {
return (
props != null) ? (
Properties)
props.
clone() : null;
}
/**
* Returns the group's command-environment control object.
* @return the command-environment object, or <code>null</code>
* @since 1.2
*/
public
CommandEnvironment getCommandEnvironment() {
return this.
env;
}
/**
* Startup options for ActivationGroup implementations.
*
* This class allows overriding default system properties and
* specifying implementation-defined options for ActivationGroups.
* @since 1.2
*/
public static class
CommandEnvironment implements
Serializable {
private static final long
serialVersionUID = 6165754737887770191L;
/**
* @serial
*/
private
String command;
/**
* @serial
*/
private
String[]
options;
/**
* Create a CommandEnvironment with all the necessary
* information.
*
* @param cmdpath the name of the java executable, including
* the full path, or <code>null</code>, meaning "use rmid's default".
* The named program <em>must</em> be able to accept multiple
* <code>-Dpropname=value</code> options (as documented for the
* "java" tool)
*
* @param argv extra options which will be used in creating the
* ActivationGroup. Null has the same effect as an empty
* list.
* @since 1.2
*/
public
CommandEnvironment(
String cmdpath,
String[]
argv)
{
this.
command =
cmdpath; // might be null
// Hold a safe copy of argv in this.options
if (
argv == null) {
this.
options = new
String[0];
} else {
this.
options = new
String[
argv.length];
System.
arraycopy(
argv, 0, this.
options, 0,
argv.length);
}
}
/**
* Fetch the configured path-qualified java command name.
*
* @return the configured name, or <code>null</code> if configured to
* accept the default
* @since 1.2
*/
public
String getCommandPath() {
return (this.
command);
}
/**
* Fetch the configured java command options.
*
* @return An array of the command options which will be passed
* to the new child command by rmid.
* Note that rmid may add other options before or after these
* options, or both.
* Never returns <code>null</code>.
* @since 1.2
*/
public
String[]
getCommandOptions() {
return
options.
clone();
}
/**
* Compares two command environments for content equality.
*
* @param obj the Object to compare with
* @return true if these Objects are equal; false otherwise.
* @see java.util.Hashtable
* @since 1.2
*/
public boolean
equals(
Object obj) {
if (
obj instanceof
CommandEnvironment) {
CommandEnvironment env = (
CommandEnvironment)
obj;
return
((
command == null ?
env.
command == null :
command.
equals(
env.
command)) &&
Arrays.
equals(
options,
env.
options));
} else {
return false;
}
}
/**
* Return identical values for similar
* <code>CommandEnvironment</code>s.
* @return an integer
* @see java.util.Hashtable
*/
public int
hashCode()
{
// hash command and ignore possibly expensive options
return (
command == null ? 0 :
command.
hashCode());
}
/**
* <code>readObject</code> for custom serialization.
*
* <p>This method reads this object's serialized form for this
* class as follows:
*
* <p>This method first invokes <code>defaultReadObject</code> on
* the specified object input stream, and if <code>options</code>
* is <code>null</code>, then <code>options</code> is set to a
* zero-length array of <code>String</code>.
*/
private void
readObject(
ObjectInputStream in)
throws
IOException,
ClassNotFoundException
{
in.
defaultReadObject();
if (
options == null) {
options = new
String[0];
}
}
}
/**
* Compares two activation group descriptors for content equality.
*
* @param obj the Object to compare with
* @return true if these Objects are equal; false otherwise.
* @see java.util.Hashtable
* @since 1.2
*/
public boolean
equals(
Object obj) {
if (
obj instanceof
ActivationGroupDesc) {
ActivationGroupDesc desc = (
ActivationGroupDesc)
obj;
return
((
className == null ?
desc.
className == null :
className.
equals(
desc.
className)) &&
(
location == null ?
desc.
location == null :
location.
equals(
desc.
location)) &&
(
data == null ?
desc.
data == null :
data.
equals(
desc.
data)) &&
(
env == null ?
desc.
env == null :
env.
equals(
desc.
env)) &&
(
props == null ?
desc.
props == null :
props.
equals(
desc.
props)));
} else {
return false;
}
}
/**
* Produce identical numbers for similar <code>ActivationGroupDesc</code>s.
* @return an integer
* @see java.util.Hashtable
*/
public int
hashCode() {
// hash location, className, data, and env
// but omit props (may be expensive)
return ((
location == null
? 0
:
location.
hashCode() << 24) ^
(
env == null
? 0
:
env.
hashCode() << 16) ^
(
className == null
? 0
:
className.
hashCode() << 8) ^
(
data == null
? 0
:
data.
hashCode()));
}
}