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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.filter.keepalive;
    21
    22  import org.apache.mina.core.session.IoSession;
    23  import org.slf4j.Logger;
    24  import org.slf4j.LoggerFactory;
    25
    26  /**
    27   * Tells {@link KeepAliveFilter} what to do when a keep-alive response message
    28   * was not received within a certain timeout.
    29   *
    30   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    31   */
    32  public interface KeepAliveRequestTimeoutHandler {
    33      /**
    34       * Do nothing.
    35       */
    36      static KeepAliveRequestTimeoutHandler NOOP = new KeepAliveRequestTimeoutHandler() {
    37          public void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception {
    38              // Do nothing.
    39          }
    40      };
    41
    42      /**
    43       * Logs a warning message, but doesn't do anything else.
    44       */
    45      static KeepAliveRequestTimeoutHandler LOG = new KeepAliveRequestTimeoutHandler() {
    46          private final Logger LOGGER = LoggerFactory.getLogger(KeepAliveFilter.class);
    47
    48          public void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception {
    49              LOGGER.warn("A keep-alive response message was not received within " + "{} second(s).",
    50                      filter.getRequestTimeout());
    51          }
    52      };
    53
    54      /**
    55       * Throws a {@link KeepAliveRequestTimeoutException}.
    56       */
    57      static KeepAliveRequestTimeoutHandler EXCEPTION = new KeepAliveRequestTimeoutHandler() {
    58          public void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception {
    59              throw new KeepAliveRequestTimeoutException("A keep-alive response message was not received within "
    60                      + filter.getRequestTimeout() + " second(s).");
    61          }
    62      };
    63
    64      /**
    65       * Closes the connection after logging.
    66       */
    67      static KeepAliveRequestTimeoutHandler CLOSE = new KeepAliveRequestTimeoutHandler() {
    68          private final Logger LOGGER = LoggerFactory.getLogger(KeepAliveFilter.class);
    69
    70          public void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception {
    71              LOGGER.warn("Closing the session because a keep-alive response "
    72                      + "message was not received within {} second(s).", filter.getRequestTimeout());
    73              session.close(true);
    74          }
    75      };
    76
    77      /**
    78       * A special handler for the 'deaf speaker' mode.
    79       */
    80      static KeepAliveRequestTimeoutHandler DEAF_SPEAKER = new KeepAliveRequestTimeoutHandler() {
    81          public void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception {
    82              throw new Error("Shouldn't be invoked.  Please file a bug report.");
    83          }
    84      };
    85
    86      /**
    87       * Invoked when {@link KeepAliveFilter} couldn't receive the response for
    88       * the sent keep alive message.
    89       */
    90      void keepAliveRequestTimedOut(KeepAliveFilter filter, IoSession session) throws Exception;
    91  }