import com.sun.jmx.remote.security.SubjectDelegator; //导入依赖的package包/类
/**
 * Constructs a new {@link RMIConnection}. This connection can be
 * used with either the JRMP or IIOP transport. This object does
 * not export itself: it is the responsibility of the caller to
 * export it appropriately (see {@link
 * RMIJRMPServerImpl#makeClient(String,Subject)} and {@link
 * RMIIIOPServerImpl#makeClient(String,Subject)}.
 *
 * @param rmiServer The RMIServerImpl object for which this
 * connection is created.  The behavior is unspecified if this
 * parameter is null.
 * @param connectionId The ID for this connection.  The behavior
 * is unspecified if this parameter is null.
 * @param defaultClassLoader The default ClassLoader to be used
 * when deserializing marshalled objects.  Can be null, to signify
 * the bootstrap class loader.
 * @param subject the authenticated subject to be used for
 * authorization.  Can be null, to signify that no subject has
 * been authenticated.
 * @param env the environment containing attributes for the new
 * <code>RMIServerImpl</code>.  Can be null, equivalent to an
 * empty map.
 */
public RMIConnectionImpl(RMIServerImpl rmiServer,
                         String connectionId,
                         ClassLoader defaultClassLoader,
                         Subject subject,
                         Map<String,?> env) {
    if (rmiServer == null || connectionId == null)
        throw new NullPointerException("Illegal null argument");
    if (env == null)
        env = Collections.emptyMap();
    this.rmiServer = rmiServer;
    this.connectionId = connectionId;
    this.defaultClassLoader = defaultClassLoader;

    this.subjectDelegator = new SubjectDelegator();
    this.subject = subject;
    if (subject == null) {
        this.acc = null;
        this.removeCallerContext = false;
    } else {
        this.removeCallerContext =
            SubjectDelegator.checkRemoveCallerContext(subject);
        if (this.removeCallerContext) {
            this.acc =
                JMXSubjectDomainCombiner.getDomainCombinerContext(subject);
        } else {
            this.acc =
                JMXSubjectDomainCombiner.getContext(subject);
        }
    }
    this.mbeanServer = rmiServer.getMBeanServer();

    final ClassLoader dcl = defaultClassLoader;
    this.classLoaderWithRepository =
        AccessController.doPrivileged(
            new PrivilegedAction<ClassLoaderWithRepository>() {
                public ClassLoaderWithRepository run() {
                    return new ClassLoaderWithRepository(
                                  mbeanServer.getClassLoaderRepository(),
                                  dcl);
                }
            });
    serverCommunicatorAdmin = new
      RMIServerCommunicatorAdmin(EnvHelp.getServerConnectionTimeout(env));

    this.env = env;
}