content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.wasp;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.ipc.RemoteException;
  
  /**
   * Subclass if the server knows the entityGroup is now on another server. This allows
   * the client to call the new entityGroup server without calling the master.
   */
  public class EntityGroupMovedException extends NotServingEntityGroupException {
    private static final Log LOG = LogFactory
        .getLog(EntityGroupMovedException.class);
    private static final long serialVersionUID = -7232903522310558397L;
  
    private final String hostname;
    private final int port;
  
    private static final String HOST_FIELD = "hostname=";
    private static final String PORT_FIELD = "port=";
  
    public EntityGroupMovedException(final String hostname, final int port) {
      super();
      this.hostname = hostname;
      this.port = port;
    }
  
    public String getHostname() {
      return hostname;
    }
  
    public int getPort() {
      return port;
    }
  
    /**
     * For hadoop.ipc internal call. Do NOT use. We have to parse the hostname to
     * recreate the exception. The input is the one generated by
     * {@link #getMessage()}
     */
    public EntityGroupMovedException(String s) {
      int posHostname = s.indexOf(HOST_FIELD) + HOST_FIELD.length();
      int posPort = s.indexOf(PORT_FIELD) + PORT_FIELD.length();
  
      String tmpHostname = null;
      int tmpPort = -1;
      try {
        tmpHostname = s.substring(posHostname, s.indexOf(' ', posHostname));
        tmpPort = Integer.parseInt(s.substring(posPort, s.indexOf('.', posPort)));
      } catch (Exception ignored) {
        LOG.warn("Can't parse the hostname and the port from this string: " + s
            + ", " + "Continuing");
      }
  
      hostname = tmpHostname;
      port = tmpPort;
    }
  
    @Override
    public String getMessage() {
      return "EntityGroup moved to: " + HOST_FIELD + hostname + " " + PORT_FIELD
          + port + ".";
    }
  
    /**
     * Look for a EntityGroupMovedException in the exception: - hadoop.ipc wrapped
     * exceptions - nested exceptions Returns null if we didn't find the exception
     * or if it was not readable.
     */
    public static EntityGroupMovedException find(Object exception) {
      if (exception == null || !(exception instanceof Throwable)) {
        return null;
      }
  
      Throwable cur = (Throwable) exception;
      EntityGroupMovedException res = null;
  
      while (res == null && cur != null) {
        if (cur instanceof EntityGroupMovedException) {
          res = (EntityGroupMovedException) cur;
        } else {
          if (cur instanceof RemoteException) {
            RemoteException re = (RemoteException) cur;
            Exception e = re
                .unwrapRemoteException(EntityGroupMovedException.class);
            if (e == null) {
              e = re.unwrapRemoteException();
            }
            // unwrapRemoteException can return the exception given as a parameter
            // when it cannot
            // unwrap it. In this case, there is no need to look further
            // noinspection ObjectEquality
            if (e != re) {
              res = find(e);
            }
          }
          cur = cur.getCause();
        }
      }
  
      if (res != null && (res.getPort() < 0 || res.getHostname() == null)) {
        // We failed to parse the exception. Let's act as we don't find the
        // exception.
        return null;
      } else {
        return res;
      }
    }
  }
  