Class RMIConnectorServer

All Implemented Interfaces:
MBeanRegistration, NotificationBroadcaster, NotificationEmitter, JMXAddressable, JMXConnectorServerMBean

public class RMIConnectorServer extends JMXConnectorServer

A JMX API connector server that creates RMI-based connections from remote clients. Usually, such connector servers are made using JMXConnectorServerFactory. However, specialized applications can use this class directly, for example with an RMIServerImpl object.

Since:
1.5
  • Field Details

    • JNDI_REBIND_ATTRIBUTE

      public static final String JNDI_REBIND_ATTRIBUTE

      Name of the attribute that specifies whether the RMIServer stub that represents an RMI connector server should override an existing stub at the same address. The value associated with this attribute, if any, should be a string that is equal, ignoring case, to "true" or "false". The default value is false.

      See Also:
      Constant Field Values
    • RMI_CLIENT_SOCKET_FACTORY_ATTRIBUTE

      public static final String RMI_CLIENT_SOCKET_FACTORY_ATTRIBUTE

      Name of the attribute that specifies the RMIClientSocketFactory for the RMI objects created in conjunction with this connector. The value associated with this attribute must be of type RMIClientSocketFactory and can only be specified in the Map argument supplied when creating a connector server.

      See Also:
      Constant Field Values
    • RMI_SERVER_SOCKET_FACTORY_ATTRIBUTE

      public static final String RMI_SERVER_SOCKET_FACTORY_ATTRIBUTE

      Name of the attribute that specifies the RMIServerSocketFactory for the RMI objects created in conjunction with this connector. The value associated with this attribute must be of type RMIServerSocketFactory and can only be specified in the Map argument supplied when creating a connector server.

      See Also:
      Constant Field Values
    • CREDENTIALS_FILTER_PATTERN

      public static final String CREDENTIALS_FILTER_PATTERN
      Name of the attribute that specifies an ObjectInputFilter pattern string to filter classes acceptable for RMIServer.newClient() remote method call.

      The filter pattern must be in same format as used in ObjectInputFilter.Config.createFilter(java.lang.String)

      This list of classes allowed by filter should correspond to the transitive closure of the credentials class (or classes) used by the installed JMXAuthenticator associated with the RMIServer implementation. If the attribute is not set then any class is deemed acceptable.

      See Also:
      ObjectInputFilter, Constant Field Values
    • SERIAL_FILTER_PATTERN

      public static final String SERIAL_FILTER_PATTERN
      This attribute defines a pattern from which to create a ObjectInputFilter that will be used when deserializing objects sent to the JMXConnectorServer by any client.

      The filter will be called for any class found in the serialized stream sent to server by client, including all JMX defined classes (such as ObjectName), all method parameters, and, if present in the stream, all classes transitively referred by the serial form of any deserialized object. The pattern must be in same format as used in ObjectInputFilter.Config.createFilter(java.lang.String). It may define an allow-list of permitted classes, a reject-list of rejected classes, a maximum depth for the deserialized objects, etc.

      To be functional, the filter should allow at least all the concrete types in the transitive closure of all objects that might get serialized when serializing all JMX classes referred as parameters in the RMIConnection interface, plus all classes that a client might need to transmit wrapped in marshalled objects in order to interoperate with the MBeans registered in the MBeanServer. That would potentially include all the concrete JMX OpenTypes and the classes they use in their serial form.

      Care must be taken when defining such a filter, as defining an allow-list that is too narrow or a reject-list that is too wide may prevent legitimate clients from interoperating with the JMXConnectorServer.

      See Also:
      Constant Field Values
  • Constructor Details

    • RMIConnectorServer

      public RMIConnectorServer(JMXServiceURL url, Map<String,​?> environment) throws IOException

      Makes an RMIConnectorServer. This is equivalent to calling RMIConnectorServer(directoryURL,environment,null,null)

      Parameters:
      url - the URL defining how to create the connector server. Cannot be null.
      environment - attributes governing the creation and storing of the RMI object. Can be null, which is equivalent to an empty Map.
      Throws:
      IllegalArgumentException - if url is null.
      MalformedURLException - if url does not conform to the syntax for an RMI connector, or if its protocol is not recognized by this implementation. Only "rmi" is valid when this constructor is used.
      IOException - if the connector server cannot be created for some reason or if it is inevitable that its start method will fail.
    • RMIConnectorServer

      public RMIConnectorServer(JMXServiceURL url, Map<String,​?> environment, MBeanServer mbeanServer) throws IOException

      Makes an RMIConnectorServer for the given MBean server. This is equivalent to calling RMIConnectorServer(directoryURL,environment,null,mbeanServer)

      Parameters:
      url - the URL defining how to create the connector server. Cannot be null.
      environment - attributes governing the creation and storing of the RMI object. Can be null, which is equivalent to an empty Map.
      mbeanServer - the MBean server to which the new connector server is attached, or null if it will be attached by being registered as an MBean in the MBean server.
      Throws:
      IllegalArgumentException - if url is null.
      MalformedURLException - if url does not conform to the syntax for an RMI connector, or if its protocol is not recognized by this implementation. Only "rmi" is valid when this constructor is used.
      IOException - if the connector server cannot be created for some reason or if it is inevitable that its start method will fail.
    • RMIConnectorServer

      public RMIConnectorServer(JMXServiceURL url, Map<String,​?> environment, RMIServerImpl rmiServerImpl, MBeanServer mbeanServer) throws IOException

      Makes an RMIConnectorServer for the given MBean server.

      Parameters:
      url - the URL defining how to create the connector server. Cannot be null.
      environment - attributes governing the creation and storing of the RMI object. Can be null, which is equivalent to an empty Map.
      rmiServerImpl - An implementation of the RMIServer interface, consistent with the protocol type specified in url. If this parameter is non null, the protocol type specified by url is not constrained, and is assumed to be valid. Otherwise, only "rmi" will be recognized.
      mbeanServer - the MBean server to which the new connector server is attached, or null if it will be attached by being registered as an MBean in the MBean server.
      Throws:
      IllegalArgumentException - if url is null.
      MalformedURLException - if url does not conform to the syntax for an RMI connector, or if its protocol is not recognized by this implementation. Only "rmi" is recognized when rmiServerImpl is null.
      IOException - if the connector server cannot be created for some reason or if it is inevitable that its start method will fail.
      See Also:
      start()
  • Method Details

    • toJMXConnector

      public JMXConnector toJMXConnector(Map<String,​?> env) throws IOException

      Returns a client stub for this connector server. A client stub is a serializable object whose connect method can be used to make one new connection to this connector server.

      Specified by:
      toJMXConnector in interface JMXConnectorServerMBean
      Overrides:
      toJMXConnector in class JMXConnectorServer
      Parameters:
      env - client connection parameters of the same sort that could be provided to JMXConnector.connect(Map). Can be null, which is equivalent to an empty map.
      Returns:
      a client stub that can be used to make a new connection to this connector server.
      Throws:
      UnsupportedOperationException - if this connector server does not support the generation of client stubs.
      IllegalStateException - if the JMXConnectorServer is not started (see isActive()).
      IOException - if a communications problem means that a stub cannot be created.
    • start

      public void start() throws IOException

      Activates the connector server, that is starts listening for client connections. Calling this method when the connector server is already active has no effect. Calling this method when the connector server has been stopped will generate an IOException.

      The behavior of this method when called for the first time depends on the parameters that were supplied at construction, as described below.

      First, an object of a subclass of RMIServerImpl is required, to export the connector server through RMI:

      • If an RMIServerImpl was supplied to the constructor, it is used.
      • Otherwise, if the JMXServiceURL was null, or its protocol part was rmi, an object of type RMIJRMPServerImpl is created.
      • Otherwise, the implementation can create an implementation-specific RMIServerImpl or it can throw MalformedURLException.

      If the given address includes a JNDI directory URL as specified in the package documentation for javax.management.remote.rmi, then this RMIConnectorServer will bootstrap by binding the RMIServerImpl to the given address.

      If the URL path part of the JMXServiceURL was empty or a single slash (/), then the RMI object will not be bound to a directory. Instead, a reference to it will be encoded in the URL path of the RMIConnectorServer address (returned by getAddress()). The encodings for rmi are described in the package documentation for javax.management.remote.rmi.

      The behavior when the URL path is neither empty nor a JNDI directory URL, or when the protocol is not rmi, is implementation defined, and may include throwing MalformedURLException when the connector server is created or when it is started.

      Throws:
      IllegalStateException - if the connector server has not been attached to an MBean server.
      IOException - if the connector server cannot be started.
    • stop

      public void stop() throws IOException

      Deactivates the connector server, that is, stops listening for client connections. Calling this method will also close all client connections that were made by this server. After this method returns, whether normally or with an exception, the connector server will not create any new client connections.

      Once a connector server has been stopped, it cannot be started again.

      Calling this method when the connector server has already been stopped has no effect. Calling this method when the connector server has not yet been started will disable the connector server object permanently.

      If closing a client connection produces an exception, that exception is not thrown from this method. A JMXConnectionNotification is emitted from this MBean with the connection ID of the connection that could not be closed.

      Closing a connector server is a potentially slow operation. For example, if a client machine with an open connection has crashed, the close operation might have to wait for a network protocol timeout. Callers that do not want to block in a close operation should do it in a separate thread.

      This method calls the method close on the connector server's RMIServerImpl object.

      If the RMIServerImpl was bound to a JNDI directory by the start method, it is unbound from the directory by this method.

      Throws:
      IOException - if the server cannot be closed cleanly, or if the RMIServerImpl cannot be unbound from the directory. When this exception is thrown, the server has already attempted to close all client connections, if appropriate; to call RMIServerImpl.close(); and to unbind the RMIServerImpl from its directory, if appropriate. All client connections are closed except possibly those that generated exceptions when the server attempted to close them.
    • isActive

      public boolean isActive()
      Description copied from interface: JMXConnectorServerMBean

      Determines whether the connector server is active. A connector server starts being active when its start method returns successfully and remains active until either its stop method is called or the connector server fails.

      Returns:
      true if the connector server is active.
    • getAddress

      public JMXServiceURL getAddress()
      Description copied from interface: JMXConnectorServerMBean

      The address of this connector server.

      The address returned may not be the exact original JMXServiceURL that was supplied when creating the connector server, since the original address may not always be complete. For example the port number may be dynamically allocated when starting the connector server. Instead the address returned is the actual JMXServiceURL of the JMXConnectorServer. This is the address that clients supply to JMXConnectorFactory.connect(JMXServiceURL).

      Note that the address returned may be null if the JMXConnectorServer is not yet active.

      Returns:
      the address of this connector server, or null if it does not have one.
    • getAttributes

      public Map<String,​?> getAttributes()
      Description copied from interface: JMXConnectorServerMBean

      The attributes for this connector server.

      Returns:
      a read-only map containing the attributes for this connector server. Attributes whose values are not serializable are omitted from this map. If there are no serializable attributes, the returned map is empty.