API java : javax.management.remote

Package javax.management.remote

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          Description

Package javax.management.remote Description

Interfaces for remote access to JMX MBean servers. This package defines the essential interfaces for making a JMX MBean server manageable remotely. The companion document JMX Remote API completes the specification of this interface. It should be available as a PDF document in the same place as this Javadoc specification.

The JMX specification defines the notion of connectors. A connector is attached to a JMX API MBean server and makes it accessible to remote Java clients. The client end of a connector exports essentially the same interface as the MBean server, specifically the MBeanServerConnection interface.

A connector makes an MBean server remotely accessible through a given protocol.
The JMX Remote API defines a standard connector, the RMI Connector, which provides remote access to an MBeanServer through RMI.
The JMX Remote API also defines an optional protocol called JMXMP (JMX Message Protocol). JMXMP is based on serialized Java objects (defined in the optional package javax.management.remote.message) over a TCP connection. The connector that implements this protocol is called the JMXMP Connector. User-defined connector protocols are also possible using the JMXConnectorFactory and, optionally, the Generic Connector (javax.management.remote.generic).

Connector addresses

Typically, a connector has an address, represented by the class JMXServiceURL. An address for the JMXMP Connector looks like this:

service:jmx:jmxmp://myhost:9876

An address for the RMI Connector can take several forms, as detailed in the documentation for the package javax.management.remote.rmi.

Creating a connector server

A connector server is created by constructing an instance of a subclass of JMXConnectorServer. Usually, this instance is created using the method JMXConnectorServerFactory.newJMXConnectorServer.

Typically, a connector server is associated with an MBean server either by registering it in that MBean server, or by supplying the MBean server as a parameter when creating the connector server.

Creating a connector client

A connector client is usually created by supplying a JMXServiceURL to the JMXConnectorFactory.connect method.

For more specialized uses, a connector client can be created by directly instantiating a class that implements the JMXConnector interface, for example the class RMIConnector.

Additional client or server parameters

When creating a connector client or server, it is possible to supply an object of type Map that defines additional parameters. Each entry in this Map has a key that is a string and an associated value whose type is appropriate for that key. The standard keys defined by the JMX Remote API all begin with the string "jmx.remote.". The document JMX Remote API lists these standard keys.

Connection identifiers

Every connection opened by a connector server has a string identifier, called its connection id. This identifier appears in the JMXConnectionNotification events emitted by the connector server, in the list returned by JMXConnectorServerMBean#getConnectionIds(), and in the value returned by the client's getConnectionId() method.

Conventionally, a connection ID looks something like this:

jmxmp://clienthost:6789 clientname xxxyyyzzz

The formal grammar for connection ids that follow this convention is as follows (using the grammar notation from The Java Language Specification, Second Edition):

<em>ConnectionId:</em>
    <em>Protocol</em> : <em>ClientAddress<sub>opt</sub></em> Space <em>ClientId<sub>opt</sub></em> Space <em>ArbitraryText</em>
 
<em>ClientAddress:</em>
    // <em>HostAddress</em> <em>ClientPort<sub>opt</sub></em>
 
<em>ClientPort</em>
    : <em>HostPort</em>

The Protocol is a protocol that would be recognized by JMXConnectorFactory.

The ClientAddress is the address and port of the connecting client, if these can be determined, otherwise nothing. The HostAddress is the Internet address of the host that the client is connecting from, in numeric or DNS form. Numeric IPv6 addresses are enclosed in square brackets []. The HostPort is the decimal port number that the client is connecting from.

The ClientId is the identity of the client entity, typically a string returned by JMXPrincipal.getName(). This string must not contain spaces.

The ArbitraryText is any additional text that the connector server adds when creating the client id. At a minimum, it must be enough to distinguish this connection ID from the ID of any other connection currently opened by this connector server.