RMIConnectorServer (Java SE 26 & JDK 26)
Description: declaration: module: java.management.rmi, package: javax.management.remote.rmi, class: RMIConnectorServer
Keywords: javax.management.remote.rmi.RMIConnectorServer class

# Class RMIConnectorServer

java.lang.Object
javax.management.NotificationBroadcasterSupport
javax.management.remote.JMXConnectorServer
javax.management.remote.rmi.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 Summary

  Fields
  Modifier and Type
  Field
  Description
  `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.
  `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.
  `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.
  `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.
  `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.

  ### Fields declared in class JMXConnectorServer

  `AUTHENTICATOR`
  Modifier and Type
  Field
  Description
  `static final String`
  `AUTHENTICATOR`
  Name of the attribute that specifies the authenticator for a connector server.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RMIConnectorServer(JMXServiceURL url, Map<String,?> environment)`
  Makes an `RMIConnectorServer`.
  `RMIConnectorServer(JMXServiceURL url, Map<String,?> environment, MBeanServer mbeanServer)`
  Makes an `RMIConnectorServer` for the given MBean server.
  `RMIConnectorServer(JMXServiceURL url, Map<String,?> environment, RMIServerImpl rmiServerImpl, MBeanServer mbeanServer)`
  Makes an `RMIConnectorServer` for the given MBean server.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `JMXServiceURL`
  `getAddress()`
  The address of this connector server.
  `Map<String,?>`
  `getAttributes()`
  The attributes for this connector server.
  `boolean`
  `isActive()`
  Determines whether the connector server is active.
  `void`
  `start()`
  Activates the connector server, that is starts listening for client connections.
  `void`
  `stop()`
  Deactivates the connector server, that is, stops listening for client connections.
  `JMXConnector`
  `toJMXConnector(Map<String,?> env)`
  Returns a client stub for this connector server.

  ### Methods declared in class JMXConnectorServer

  `connectionClosed, connectionFailed, connectionOpened, getConnectionIds, getMBeanServer, getNotificationInfo, postDeregister, postRegister, preDeregister, preRegister, setMBeanServerForwarder`
  Modifier and Type
  Method
  Description
  `protected void`
  `connectionClosed(String connectionId, String message, Object userData)`
  Called by a subclass when a client connection is closed normally.
  `protected void`
  `connectionFailed(String connectionId, String message, Object userData)`
  Called by a subclass when a client connection fails.
  `protected void`
  `connectionOpened(String connectionId, String message, Object userData)`
  Called by a subclass when a new client connection is opened.
  `String[]`
  `getConnectionIds()`
  The list of IDs for currently-open connections to this connector server.
  `MBeanServer`
  `getMBeanServer()`
  Returns the MBean server that this connector server is attached to.
  `MBeanNotificationInfo[]`
  `getNotificationInfo()`
  Returns an array indicating the notifications that this MBean sends.
  `void`
  `postDeregister()`
  Allows the MBean to perform any operations needed after having been unregistered in the MBean server.
  `void`
  `postRegister(Boolean registrationDone)`
  Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.
  `void`
  `preDeregister()`
  Called by an MBean server when this connector server is unregistered from that MBean server.
  `ObjectName`
  `preRegister(MBeanServer mbs, ObjectName name)`
  Called by an MBean server when this connector server is registered in that MBean server.
  `void`
  `setMBeanServerForwarder(MBeanServerForwarder mbsf)`
  Inserts an object that intercepts requests for the MBean server that arrive through this connector server.

  ### Methods declared in class NotificationBroadcasterSupport

  `addNotificationListener, handleNotification, removeNotificationListener, removeNotificationListener, sendNotification`
  Modifier and Type
  Method
  Description
  `void`
  `addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback)`
  Adds a listener.
  `protected void`
  `handleNotification(NotificationListener listener, Notification notif, Object handback)`
  This method is called by `sendNotification` for each listener in order to send the notification to that listener.
  `void`
  `removeNotificationListener(NotificationListener listener)`
  Removes a listener from this MBean.
  `void`
  `removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback)`
  Removes a listener from this MBean.
  `void`
  `sendNotification(Notification notification)`
  Sends a notification.

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`
  Modifier and Type
  Method
  Description
  `protected Object`
  `clone()`
  Creates and returns a copy of this object.
  `boolean`
  `equals(Object obj)`
  Indicates whether some other object is "equal to" this one.
  `protected void`
  `finalize()`
  Deprecated, for removal: This API element is subject to removal in a future version.
  Finalization is deprecated and subject to removal in a future release.
  `final Class<?>`
  `getClass()`
  Returns the runtime class of this `Object`.
  `int`
  `hashCode()`
  Returns a hash code value for this object.
  `final void`
  `notify()`
  Wakes up a single thread that is waiting on this object's monitor.
  `final void`
  `notifyAll()`
  Wakes up all threads that are waiting on this object's monitor.
  `String`
  `toString()`
  Returns a string representation of the object.
  `final void`
  `wait()`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
  `final void`
  `wait(long timeoutMillis)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
  `final void`
  `wait(long timeoutMillis, int nanos)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

- ## 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(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.

    Since:
      10
    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(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`.

    Since:
      10
    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.