com.alibaba.wasp.EntityGroupMovedException.java Source code

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Here is the source code for com.alibaba.wasp.EntityGroupMovedException.java

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/**
 * 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;
        }
    }
}