rampart_1_1/modules/kernel/src/org/apache/axis2/transport/http/server/DefaultConnectionListenerFailureHandler.java

/*
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 *
 * ====================================================================
 *
 *  Copyright 1999-2006 The Apache Software Foundation
 *
 *  Licensed 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
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 *  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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
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package org.apache.axis2.transport.http.server;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/** Default hander for failures in connection listener IOProcessors.
 *  Supports configuration of number retries, delay per retry, and uptime interval considered a success (resets number retries to zero).
 */
public class DefaultConnectionListenerFailureHandler implements ConnectionListenerFailureHandler {
    
    private static final Log LOG = LogFactory.getLog(DefaultConnectionListenerFailureHandler.class);

    protected int retryDelay;
    protected int successInterval;
    protected int maxRetries;
    
    private long lastFailure;
    private long lastFirstFailure;
    private int numRetries;
    
    /** Create a new DefaultConnectionListenerFailureHandler with default settings.
     * retryDelay is 1 second, successInterval is 60 seconds, maxRetries is 10
     */
    public DefaultConnectionListenerFailureHandler() {
        this(1000, 60000, 10);
    }

    /** Create a new DefaultConnectionListenerFailureHandler
     * @param retryDelay millis to wait before retrying
     * @param successInterval millis after which an initial or retry attempt will be deemed a success, resetting retry count to 0
     * @param maxRetries maximum number of retries allowed without a success, after which the listener will terminate
     */
    public DefaultConnectionListenerFailureHandler(int retryDelay, int successInterval, int maxRetries) {
        this.retryDelay = retryDelay;
        this.successInterval = successInterval;
        this.maxRetries = maxRetries;
        this.lastFailure = this.lastFirstFailure = Long.MIN_VALUE;
        this.numRetries = 0;
    }

    /** Default behavior is to log a warning and attempt retry per constructor config, eventually failing with a logged error and notification.
     * May subclass and override this method to change the behavior.
     */
    public boolean failed(IOProcessor connectionListener, Throwable cause) {
        long now = System.currentTimeMillis();
        if (now > lastFailure+successInterval) {
            numRetries = 0;
            lastFirstFailure = now;
        }
        lastFailure = now;
        if (numRetries >= maxRetries) {
            notifyAbnormalTermination(
                    connectionListener,
                    "Terminating connection listener " + connectionListener + " after " + numRetries + "retries in " + (now-lastFirstFailure)/1000 + " seconds.",
                    cause);
            return false;
        } else {
            numRetries++;
            if (LOG.isWarnEnabled())
                LOG.warn("Attempt number " + numRetries + " of " + maxRetries + " to reestalish connection listener " + connectionListener + " due to failure ",
                         cause);
            return true;
        }
    }

    /** Default bevarior is to log the error.
     * May subclass and override this method to change behavior.
     */
    public void notifyAbnormalTermination(IOProcessor connectionListener, String message, Throwable cause) {
        LOG.error(message, cause);
    }
    
}