# Class RMIServerImpl

java.lang.Object
javax.management.remote.rmi.RMIServerImpl

All Implemented Interfaces:
  `Closeable, AutoCloseable, Remote, RMIServer`

Direct Known Subclasses:
  `RMIJRMPServerImpl`

public abstract class RMIServerImpl extends Object implements Closeable, RMIServer

An RMI object representing a connector server. Remote clients can make connections using the `newClient(Object)` method. This method returns an RMI object representing the connection.

User code does not usually reference this class directly. RMI connection servers are usually created with the class `RMIConnectorServer`. Remote clients usually create connections either with `JMXConnectorFactory` or by instantiating `RMIConnector`.

This is an abstract class. Concrete subclasses define the details of the client connection objects.

Since:
  1.5

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RMIServerImpl(Map<String,?> env)`
  Constructs a new `RMIServerImpl`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected void`
  `clientClosed(RMIConnection client)`
  Method called when a client connection created by `makeClient` is closed.
  `void`
  `close()`
  Closes this connection server.
  `protected abstract void`
  `closeClient(RMIConnection client)`
  Closes a client connection made by `makeClient`.
  `protected abstract void`
  `closeServer()`
  Called by `close()` to close the connector server.
  `protected abstract void`
  `export()`
  Exports this RMI object.
  `ClassLoader`
  `getDefaultClassLoader()`
  Gets the default `ClassLoader` used by this connector server.
  `MBeanServer`
  `getMBeanServer()`
  The `MBeanServer` to which this connector server is attached.
  `protected abstract String`
  `getProtocol()`
  Returns the protocol string for this object.
  `String`
  `getVersion()`
  The version of the RMI Connector Protocol understood by this connector server.
  `protected abstract RMIConnection`
  `makeClient(String connectionId, Subject subject)`
  Creates a new client connection.
  `RMIConnection`
  `newClient(Object credentials)`
  Creates a new client connection.
  `void`
  `setDefaultClassLoader(ClassLoader cl)`
  Sets the default `ClassLoader` for this connector server.
  `void`
  `setMBeanServer(MBeanServer mbs)`
  Sets the `MBeanServer` to which this connector server is attached.
  `abstract Remote`
  `toStub()`
  Returns a remotable stub for this server object.

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### RMIServerImpl

    public RMIServerImpl(Map<String,?> env)

    Constructs a new `RMIServerImpl`.

    Parameters:
      `env` - the environment containing attributes for the new `RMIServerImpl`. Can be null, which is equivalent to an empty Map.

- ## Method Details

  - ### export

    protected abstract void export() throws IOException

    Exports this RMI object.

    Throws:
      `IOException` - if this RMI object cannot be exported.

  - ### toStub

    public abstract Remote toStub() throws IOException
    Returns a remotable stub for this server object.
    Returns:
      a remotable stub.
    Throws:
      `IOException` - if the stub cannot be obtained - e.g the RMIServerImpl has not been exported yet.

  - ### setDefaultClassLoader

    public void setDefaultClassLoader(ClassLoader cl)

    Sets the default `ClassLoader` for this connector server. New client connections will use this classloader. Existing client connections are unaffected.

    Parameters:
      `cl` - the new `ClassLoader` to be used by this connector server.
    See Also:
      - `getDefaultClassLoader()`

  - ### getDefaultClassLoader

    public ClassLoader getDefaultClassLoader()

    Gets the default `ClassLoader` used by this connector server.

    Returns:
      the default `ClassLoader` used by this connector server.
    See Also:
      - `setDefaultClassLoader(ClassLoader)`

  - ### setMBeanServer

    public void setMBeanServer(MBeanServer mbs)

    Sets the `MBeanServer` to which this connector server is attached. New client connections will interact with this `MBeanServer`. Existing client connections are unaffected.

    Parameters:
      `mbs` - the new `MBeanServer`. Can be null, but new client connections will be refused as long as it is.
    See Also:
      - `getMBeanServer()`

  - ### getMBeanServer

    public MBeanServer getMBeanServer()

    The `MBeanServer` to which this connector server is attached. This is the last value passed to `setMBeanServer(MBeanServer)` on this object, or null if that method has never been called.

    Returns:
      the `MBeanServer` to which this connector is attached.
    See Also:
      - `setMBeanServer(MBeanServer)`

  - ### getVersion

    public String getVersion()
    Description copied from interface: `RMIServer`

    The version of the RMI Connector Protocol understood by this connector server. This is a string with the following format:

        protocol-version implementation-name

    The `protocol-version` is a series of two or more non-negative integers separated by periods (`.`). An implementation of the version described by this documentation must use the string `1.0` here.

    After the protocol version there must be a space, followed by the implementation name. The format of the implementation name is unspecified. It is recommended that it include an implementation version number. An implementation can use an empty string as its implementation name, for example for security reasons.

    Specified by:
      `getVersion` in interface `RMIServer`
    Returns:
      a string with the format described here.

  - ### newClient

    public RMIConnection newClient(Object credentials) throws IOException

    Creates a new client connection. This method calls `makeClient` and adds the returned client connection object to an internal list. When this `RMIServerImpl` is shut down via its `close()` method, the `close()` method of each object remaining in the list is called.

    The fact that a client connection object is in this internal list does not prevent it from being garbage collected.

    Specified by:
      `newClient` in interface `RMIServer`
    Parameters:
      `credentials` - this object specifies the user-defined credentials to be passed in to the server in order to authenticate the caller before creating the `RMIConnection`. Can be null.
    Returns:
      the newly-created `RMIConnection`. This is usually the object created by `makeClient`, though an implementation may choose to wrap that object in another object implementing `RMIConnection`.
    Throws:
      `IOException` - if the new client object cannot be created or exported.
      `SecurityException` - if the given credentials do not allow the server to authenticate the user successfully.
      `IllegalStateException` - if `getMBeanServer()` is null.

  - ### makeClient

    protected abstract RMIConnection makeClient(String connectionId, Subject subject) throws IOException

    Creates a new client connection. This method is called by the public method `newClient(Object)`.

    Parameters:
      `connectionId` - the ID of the new connection. Every connection opened by this connector server will have a different ID. The behavior is unspecified if this parameter is null.
      `subject` - the authenticated subject. Can be null.
    Returns:
      the newly-created `RMIConnection`.
    Throws:
      `IOException` - if the new client object cannot be created or exported.

  - ### closeClient

    protected abstract void closeClient(RMIConnection client) throws IOException

    Closes a client connection made by `makeClient`.

    Parameters:
      `client` - a connection previously returned by `makeClient` on which the `closeClient` method has not previously been called. The behavior is unspecified if these conditions are violated, including the case where `client` is null.
    Throws:
      `IOException` - if the client connection cannot be closed.

  - ### getProtocol

    protected abstract String getProtocol()

    Returns the protocol string for this object. The string is `rmi` for RMI/JRMP.

    Returns:
      the protocol string for this object.

  - ### clientClosed

    protected void clientClosed(RMIConnection client) throws IOException

    Method called when a client connection created by `makeClient` is closed. A subclass that defines `makeClient` must arrange for this method to be called when the resultant object's `close` method is called. This enables it to be removed from the `RMIServerImpl`'s list of connections. It is not an error for `client` not to be in that list.

    After removing `client` from the list of connections, this method calls `closeClient(client)`.

    Parameters:
      `client` - the client connection that has been closed.
    Throws:
      `IOException` - if `closeClient(RMIConnection)` throws this exception.
      `NullPointerException` - if `client` is null.

  - ### close

    public void close() throws IOException

    Closes this connection server. This method first calls the `closeServer()` method so that no new client connections will be accepted. Then, for each remaining `RMIConnection` object returned by `makeClient`, its `close` method is called.

    The behavior when this method is called more than once is unspecified.

    If `closeServer()` throws an `IOException`, the individual connections are nevertheless closed, and then the `IOException` is thrown from this method.

    If `closeServer()` returns normally but one or more of the individual connections throws an `IOException`, then, after closing all the connections, one of those `IOException`s is thrown from this method. If more than one connection throws an `IOException`, it is unspecified which one is thrown from this method.

    Specified by:
      `close` in interface `AutoCloseable`
    Specified by:
      `close` in interface `Closeable`
    Throws:
      `IOException` - if `closeServer()` or one of the `RMIConnection.close()` calls threw `IOException`.

  - ### closeServer

    protected abstract void closeServer() throws IOException

    Called by `close()` to close the connector server. After returning from this method, the connector server must not accept any new connections.

    Throws:
      `IOException` - if the attempt to close the connector server failed.