--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/management/remote/rmi/package.html Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,404 @@
+<html>
+<head>
+ <title>RMI connector</title>
+<!--
+Copyright 2002-2006 Sun Microsystems, Inc. All Rights Reserved.
+DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+
+This code is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License version 2 only, as
+published by the Free Software Foundation. Sun designates this
+particular file as subject to the "Classpath" exception as provided
+by Sun in the LICENSE file that accompanied this code.
+
+This code is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+version 2 for more details (a copy is included in the LICENSE file that
+accompanied this code).
+
+You should have received a copy of the GNU General Public License version
+2 along with this work; if not, write to the Free Software Foundation,
+Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+CA 95054 USA or visit www.sun.com if you need additional information or
+have any questions.
+-->
+</head>
+<body bgcolor="white">
+ <p>The RMI connector is a connector for the JMX Remote API that
+ uses RMI to transmit client requests to a remote MBean server.
+ This package defines the classes that the user of an RMI
+ connector needs to reference directly, for both the client and
+ server sides. It also defines certain classes that the user
+ will not usually reference directly, but that must be defined so
+ that different implementations of the RMI connector can
+ interoperate.</p>
+
+ <p>The RMI connector supports both the JRMP and the IIOP transports
+ for RMI.</p>
+
+ <p>Like most connectors in the JMX Remote API, an RMI connector
+ usually has an address, which
+ is a {@link javax.management.remote.JMXServiceURL
+ JMXServiceURL}. The protocol part of this address is
+ <code>rmi</code> for a connector that uses the default RMI
+ transport (JRMP), or <code>iiop</code> for a connector that
+ uses RMI/IIOP.</p>
+
+ <p>There are two forms for RMI connector addresses:</p>
+
+ <ul>
+ <li>
+ In the <em>JNDI form</em>, the URL indicates <em>where to find
+ an RMI stub for the connector</em>. This RMI stub is a Java
+ object of type {@link javax.management.remote.rmi.RMIServer
+ RMIServer} that gives remote access to the connector server.
+ With this address form, the RMI stub is obtained from an
+ external directory entry included in the URL. An external
+ directory is any directory recognized by {@link javax.naming
+ JNDI}, typically the RMI registry, LDAP, or COS Naming.
+
+ <li>
+ In the <em>encoded form</em>, the URL directly includes the
+ information needed to connect to the connector server. When
+ using RMI/JRMP, the encoded form is the serialized RMI stub
+ for the server object, encoded using BASE64 without embedded
+ newlines. When using RMI/IIOP, the encoded form is the CORBA
+ IOR for the server object.
+ </ul>
+
+ <p>Addresses are covered in more detail below.</p>
+
+
+ <h3>Creating an RMI connector server</h3>
+
+ <p>The usual way to create an RMI connector server is to supply an
+ RMI connector address to the method {@link
+ javax.management.remote.JMXConnectorServerFactory#newJMXConnectorServer
+ JMXConnectorServerFactory.newJMXConnectorServer}. The MBean
+ server to which the connector server is attached can be
+ specified as a parameter to that method. Alternatively, the
+ connector server can be registered as an MBean in that MBean
+ server.</p>
+
+ <p>An RMI connector server can also be created by constructing an
+ instance of {@link
+ javax.management.remote.rmi.RMIConnectorServer
+ RMIConnectorServer}, explicitly or through the MBean server's
+ <code>createMBean</code> method.</p>
+
+ <h4>Choosing the RMI transport</h4>
+
+ <p>You can choose the RMI transport (JRMP or IIOP) by specifying
+ <code>rmi</code> or <code>iiop</code> in the
+ <code><em>protocol</em></code> part of the
+ <code>serviceURL</code> when creating the connector server. You
+ can also create specialised connector servers by instantiating
+ an appropriate subclass of {@link
+ javax.management.remote.rmi.RMIServerImpl RMIServerImpl} and
+ supplying it to the <code>RMIConnectorServer</code>
+ constructor.</p>
+
+
+ <h4><a name="servergen">Connector addresses generated by the
+ server</a></h4>
+
+ <p>If the <code>serviceURL</code> you specify has an empty URL
+ path (after the optional host and port), or if you do not
+ specify a <code>serviceURL</code>, then the connector server
+ will fabricate a new <code>JMXServiceURL</code> that clients can
+ use to connect:</p>
+
+ <ul>
+
+ <li><p>If the <code>serviceURL</code> looks like:</p>
+
+ <pre>
+ <code>service:jmx:rmi://<em>host</em>:<em>port</em></code>
+ </pre>
+
+ <p>then the connector server will generate an {@link
+ javax.management.remote.rmi.RMIJRMPServerImpl
+ RMIJRMPServerImpl} and the returned <code>JMXServiceURL</code>
+ looks like:</p>
+
+ <pre>
+ <code>service:jmx:rmi://<em>host</em>:<em>port</em>/stub/<em>XXXX</em></code>
+ </pre>
+
+ <p>where <code><em>XXXX</em></code> is the serialized form of the
+ stub for the generated object, encoded in BASE64 without
+ newlines.</p>
+
+ <li><p>If the <code>serviceURL</code> looks like:</p>
+
+ <pre>
+ <code>service:jmx:iiop://<em>host</em>:<em>port</em></code>
+ </pre>
+
+ <p>then the connector server will generate an {@link
+ javax.management.remote.rmi.RMIIIOPServerImpl
+ RMIIIOPServerImpl} and the returned
+ <code>JMXServiceURL</code> looks like:</p>
+
+ <pre>
+ <code>service:jmx:iiop://<em>host</em>:<em>port</em>/ior/IOR:<em>XXXX</em></code>
+ </pre>
+
+ <p>where <code>IOR:<em>XXXX</em></code> is the standard CORBA
+ encoding of the Interoperable Object Reference for the
+ generated object.</p>
+
+ <li><p>If there is no <code>serviceURL</code>, there must be a
+ user-provided <code>RMIServerImpl</code>. If the {@link
+ javax.management.remote.rmi.RMIServerImpl#toStub toStub}
+ method on this object returns an instance of {@link
+ javax.rmi.CORBA.Stub}, then the connector server will generate
+ a <code>JMXServiceURL</code> using the <code>iiop</code>
+ form above. Otherwise, it will generate a
+ <code>JMXServiceURL</code> using the <code>rmi</code>
+ form.</p>
+
+ </ul>
+
+ <p>The <code><em>host</em></code> in a user-provided
+ <code>serviceURL</code> is optional. If present, it is copied
+ into the generated <code>JMXServiceURL</code> but otherwise
+ ignored. If absent, the generated <code>JXMServiceURL</code>
+ will have the local host name.</p>
+
+ <p>The <code><em>port</em></code> in a user-provided
+ <code>serviceURL</code> is also optional. If present, it is
+ also copied into the generated <code>JMXServiceURL</code>;
+ otherwise, the generated <code>JMXServiceURL</code> has no port.
+ For an <code>serviceURL</code> using the <code>rmi</code>
+ protocol, the <code><em>port</em></code>, if present, indicates
+ what port the generated remote object should be exported on. It
+ has no other effect.</p>
+
+ <p>If the user provides an <code>RMIServerImpl</code> rather than a
+ <code>JMXServiceURL</code>, then the generated
+ <code>JMXServiceURL</code> will have the local host name in its
+ <code><em>host</em></code> part and no
+ <code><em>port</em></code>.</p>
+
+
+ <h4><a name="directory">Connector addresses based on directory
+ entries</a></h4>
+
+ <p>As an alternative to the generated addresses just described,
+ the <code>serviceURL</code> address supplied when creating a
+ connector server can specify a <em>directory address</em> in
+ which to store the provided or generated <code>RMIServer</code>
+ stub. This directory address is then used by both client and
+ server.</p>
+
+ <p>In this case, the <code>serviceURL</code> has one of these two
+ forms:</p>
+
+ <pre>
+ <code>service:jmx:rmi://<em>host</em>:<em>port</em>/jndi/<em>jndi-name</em></code>
+ <code>service:jmx:iiop://<em>host</em>:<em>port</em>/jndi/<em>jndi-name</em></code>
+ </pre>
+
+ <p>Here, <code><em>jndi-name</em></code> is a string that can be
+ supplied to {@link javax.naming.InitialContext#bind
+ javax.naming.InitialContext.bind}.</p>
+
+ <p>As usual, the <code><em>host</em></code> and
+ <code>:<em>port</em></code> can be omitted.</p>
+
+ <p>The connector server will generate an
+ <code>RMIServerImpl</code> based on the protocol
+ (<code>rmi</code> or <code>iiop</code>) and, for
+ <code>rmi</code>, the <code><em>port</em></code> if any. When
+ the connector server is started, it will derive a stub from this
+ object using its {@link
+ javax.management.remote.rmi.RMIServerImpl#toStub toStub} method
+ and store the object using the given
+ <code><em>jndi-name</em></code>. The properties defined by the
+ JNDI API are consulted as usual.</p>
+
+ <p>For example, if the <code>JMXServiceURL</code> is:
+
+ <pre>
+ <code>service:jmx:rmi://ignoredhost/jndi/rmi://myhost/myname</code>
+ </pre>
+
+ then the connector server will generate an
+ <code>RMIJRMPServerImpl</code> and store its stub using the JNDI
+ name
+
+ <pre>
+ <code>rmi://myhost/myname</code>
+ </pre>
+
+ which means entry <code>myname</code> in the RMI registry
+ running on the default port of host <code>myhost</code>. Note
+ that the RMI registry only allows registration from the local
+ host. So, in this case, <code>myhost</code> must be the name
+ (or a name) of the host that the connector server is running
+ on.</p>
+
+ <p>In this <code>JMXServiceURL</code>, the first <code>rmi:</code>
+ specifies the RMI
+ connector, while the second <code>rmi:</code> specifies the RMI
+ registry.</p>
+
+ <p>As another example, if the <code>JMXServiceURL</code> is:
+
+ <pre>
+ <code>service:jmx:iiop://ignoredhost/jndi/ldap://dirhost:9999/cn=this,ou=that</code>
+ </pre>
+
+ then the connector server will generate an
+ <code>RMIIIOPServerImpl</code> and store its stub using the JNDI
+ name
+
+ <pre>
+ <code>ldap://dirhost:9999/cn=this,ou=that</code>
+ </pre>
+
+ which means entry <code>cn=this,ou=that</code> in the LDAP
+ directory running on port 9999 of host <code>dirhost</code>.</p>
+
+ <p>If the <code>JMXServiceURL</code> is:
+
+ <pre>
+ <code>service:jmx:iiop://ignoredhost/jndi/cn=this,ou=that</code>
+ </pre>
+
+ then the connector server will generate an
+ <code>RMIIIOPServerImpl</code> and store its stub using the JNDI
+ name
+
+ <pre>
+ <code>cn=this,ou=that</code>
+ </pre>
+
+ For this case to work, the JNDI API must have been configured
+ appropriately to supply the information about what directory to
+ use.</p>
+
+ <p>In these examples, the host name <code>ignoredhost</code> is
+ not used by the connector server or its clients. It can be
+ omitted, for example:</p>
+
+ <pre>
+ <code>service:jmx:iiop:///jndi/cn=this,ou=that</code>
+ </pre>
+
+ <p>However, it is good practice to use the name of the host
+ where the connector server is running. This is often different
+ from the name of the directory host.</p>
+
+
+ <h4>Connector server attributes</h4>
+
+ <p>When using the default JRMP transport, RMI socket factories can
+ be specified using the attributes
+ <code>jmx.remote.rmi.client.socket.factory</code> and
+ <code>jmx.remote.rmi.server.socket.factory</code> in the
+ <code>environment</code> given to the
+ <code>RMIConnectorServer</code> constructor. The values of these
+ attributes must be of type {@link
+ java.rmi.server.RMIClientSocketFactory} and {@link
+ java.rmi.server.RMIServerSocketFactory}, respectively. These
+ factories are used when creating the RMI objects associated with
+ the connector.</p>
+
+ <h3>Creating an RMI connector client</h3>
+
+ <p>An RMI connector client is usually constructed using {@link
+ javax.management.remote.JMXConnectorFactory}, with a
+ <code>JMXServiceURL</code> that has <code>rmi</code> or
+ <code>iiop</code> as its protocol.</p>
+
+ <p>If the <code>JMXServiceURL</code> was generated by the server,
+ as described above under <a href="#servergen">"connector
+ addresses generated by the server"</a>, then the client will
+ need to obtain it directly or indirectly from the server.
+ Typically, the server makes the <code>JMXServiceURL</code>
+ available by storing it in a file or a lookup service.</p>
+
+ <p>If the <code>JMXServiceURL</code> uses the directory syntax, as
+ described above under <a href="#directory">"connector addresses
+ based on directory entries"</a>, then the client may obtain it
+ as just explained, or client and server may both know the
+ appropriate directory entry to use. For example, if the
+ connector server for the Whatsit agent uses the entry
+ <code>whatsit-agent-connector</code> in the RMI registry on host
+ <code>myhost</code>, then client and server can both know
+ that the appropriate <code>JMXServiceURL</code> is:</p>
+
+ <pre>
+ <code>service:jmx:rmi:///jndi/rmi://myhost/whatsit-agent-connector</code>
+ </pre>
+
+ <p>If you have an RMI stub of type {@link
+ javax.management.remote.rmi.RMIServer RMIServer}, you can
+ construct an RMI connection directly by using the appropriate
+ constructor of {@link javax.management.remote.rmi.RMIConnector
+ RMIConnector}.</p>
+
+
+ <h3>Specifying an ORB for the RMI/IIOP connector</h3>
+
+ <p>When using the IIOP transport, the client and server can
+ specify what ORB to use
+ with the attribute <code>java.naming.corba.orb</code>.
+ Connection to the ORB happens at {@link
+ javax.management.remote.rmi.RMIConnectorServer#start() start} time
+ for the connector server, and at {@link
+ javax.management.remote.rmi.RMIConnector#connect(java.util.Map)
+ connect} time for the connector client.
+ If the <code>java.naming.corba.orb</code> attribute is contained
+ in the environment Map, then its value (an {@link
+ org.omg.CORBA.ORB ORB}), is used to connect the IIOP Stubs.
+ Otherwise, a new org.omg.CORBA.ORB is created by calling {@link
+ org.omg.CORBA.ORB
+ org.omg.CORBA.ORB.init((String[])null,(Properties)null)}. A
+ later RMI connector client or server in the same JVM can reuse
+ this ORB, or it can create another one in the same way.</p>
+
+ <p>If the <code>java.naming.corba.orb</code> attribute is
+ specified and does not point to an {@link org.omg.CORBA.ORB ORB},
+ then an <code>{@link java.lang.IllegalArgumentException}</code>
+ will be thrown.</p>
+
+ <p>The mechanism described here does not apply when the IIOP
+ Remote objects (Stubs or Servers) are created and connected to
+ an ORB manually before being passed to the RMIConnector and
+ RMIConnectorServer.</p>
+
+
+ <h3>Dynamic code downloading</h3>
+
+ <p>If an RMI connector client or server receives from its peer an
+ instance of a class that it does not know, and if dynamic code
+ downloading is active for the RMI connection, then the class can
+ be downloaded from a codebase specified by the peer. The
+ article <a
+ href="{@docRoot}/../technotes/guides/rmi/codebase.html"><em>Dynamic
+ code downloading using Java RMI</em></a> explains this in more
+ detail.</p>
+
+
+ @see <a href="{@docRoot}/../technotes/guides/rmi/index.html">
+ Java<sup><font size="-1">TM</font></sup> Remote Method
+ Invocation (RMI)</a>
+
+ @see <a href="{@docRoot}/../technotes/guides/jndi/index.html">
+ Java Naming and Directory Interface<sup><font
+ size="-1">TM</font></sup> (JNDI)</a>
+
+ @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045,
+ section 6.8, "Base64 Content-Transfer-Encoding"</a>
+
+
+ @since 1.5
+
+ </body>
+</html>