Jini(TM) Technology Extended Platform (JXP) Release Notes

JiniTM Technology Extended Platform (JXP) 1.0 Release Notes


The Jini Technology Extended Platform (JXP) software distribution consists of standard Jini software extension and utility specifications, the classes and interfaces defined in those specifications, the API documentation from those classes and interfaces, release notes for those classes and interfaces, and references to the specific copyrights and licenses that protect each of the aforementioned components.

This document contains release notes for JiniTM Discovery JiniTM Lookup,  and JavaSpacesTM Technology specifications and software.

If you have comments on the JXP, you can send email to jini-comments@java.sun.com. If you would like to submit a bug against the JXP, please send it to jini-submit@java.sun.com. If you encounter problems that you would like help with, you can subscribe to the jini-users list by sending email to listserv@java.sun.com, with a message of "subscribe jini-users".


Notes on JiniTM Discovery 1.0

What's Important

The net.jini.discovery.LookupDiscovery class provides an API which may be used to find Jini Lookup services which are nearby (LAN). To provide these capabilities, the implementation of this class makes use of a set of network protocols in conjunction with asynchronous event delivery.

Notable features of the LookupDiscovery API are described below:

System properties

Several system properties -- some documented in the specification, some not -- control the operation of the LookupDiscovery API. They are as follows:

net.jini.discovery.debug
If set to any value, this property indicates that debugging information related to the execution of the Jini Discovery and Join protocols should be printed to System.err.

net.jini.discovery.mtu
If set, this property must be an integer between 512 and the maximum MTU allowed by your system. The value of this property specifies the maximum permissible size of multicast request and announcement packets. The default value is 512.

net.jini.discovery.ttl
If set, this property must be an integer between 1 and 255. This property specifies the time-to-live parameter used by both the multicast announcement and multicast request protocol implementations. The default value is 15.

net.jini.discovery.timeout
When a client or service uses the unicast request protocol to communicate with a particular lookup service, the socket connection used by the protocol will time out after N milliseconds, where N is defined by this property. The default value is 60,000 milliseconds (1 minute).

Known Issues

When attempting to use the discovery protocol on the SolarisTM operating system, the following exception can occur if the system is not configured correctly:

    java.net.SocketException: error setting options

There are two actions that can be taken to diagnose this problem. First, verify that your network interfaces are configured for multicast by typing the following at the command prompt:

    ifconfig -a

If your interfaces are configured for multicast, then the output to the above command should contain the word MULTICAST for each interface. For example, output to this command from a correctly-configured system would look something like:

    lo0: flags=849<UP,LOOPBACK,RUNNING,MULTICAST> mtu 8232        
    	    inet 127.0.0.1 netmask ff000000
    hme0: flags=863<UP,BROADCAST,NOTRAILERS,RUNNING,MULTICAST> mtu 1500    
	    inet 129.148.54.200 netmask ffffff00 broadcast 129.148.54.255

Where the line containing the "inet" and "broadcast" IP addresses (inet 129.148.54.200 netmask ffffff00 broadcast 129.148.54.255) will contain addresses particular to your system.

If your interfaces are not configured for multicast, have your system administrator reconfigure your system for multicast.

If your interfaces are configured for multicast, then the problem may be that multicast routing is not configured. To determine whether this is the problem, type the following at the command line:

    netstat -nr

This command should produce output of the form:

      Routing Table:
        Destination           Gateway           Flags  Ref   Use   Interface
      -------------------- -------------------- ----- ----- ------ ---------
      129.148.54.0         129.148.54.200        U        3   9740   hme0 
      224.0.0.0            129.148.54.200        U        3      0   hme0 
      default              129.148.54.157        UG       0  13646 
      127.0.0.1            127.0.0.1             UH       0 662071   lo0 

If the output does not list the destination address 224.0.0.0, check to see if the default interface for multicast route configuration has been set in the file /etc/rc2.d/S72inetsvc. On a machine installed with the Solaris 2.6 operating system, you should see the line:

    /usr/sbin/route add -interface -netmask "240.0.0.0" "224.0.0.0" "$mcastif"

This line typically appears near the bottom of the file. If it does not appear, or is commented out, the default interface for multicast is not set. Have your system administrator modify this file to set this interface for your system.


Notes on the JiniTM Lookup service 1.0

What's Important

Basic attribute classes, along with a mechanism for treating attribute sets as JavaBeansTM components, are contained in the package net.jini.lookup.entry.

Use the following administrative interfaces to control participation in the Jini Join protocol:


Notes on the JavaSpacesTM Technology 1.0

Changes Since Beta

The JavaSpaces Technology Specification has changed in the following ways since its Beta release:


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Sun Microsystems, Inc. All Rights Reserved.