contrib/jcr-server/webdav/src/java/org/apache/jackrabbit/webdav/header/TimeoutHeader.java

/*
 * Copyright 2005 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
 *
 * 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 org.apache.jackrabbit.webdav.header;

import org.apache.log4j.Logger;
import org.apache.jackrabbit.webdav.DavConstants;

import javax.servlet.http.HttpServletRequest;

/**
 * <code>TimeoutHeader</code>...
 */
public class TimeoutHeader implements Header, DavConstants {

    private static Logger log = Logger.getLogger(TimeoutHeader.class);

    private final long timeout;

    public TimeoutHeader(long timeout) {
        this.timeout = timeout;
    }

    public String getHeaderName() {
        return DavConstants.HEADER_TIMEOUT;
    }

    public String getHeaderValue() {
        return String.valueOf(timeout);
    }

    public long getTimeout() {
        return timeout;
    }

    /**
     * Parse the request timeout header and convert the timeout value
     * into a long indicating the number of milliseconds until expiration time
     * is reached.<br>
     * NOTE: If the requested timeout is 'infinite' {@link Long.MAX_VALUE}
     * is returned. If the header is missing or is in an invalid format that
     * cannot be parsed, the default value is returned.
     *
     * @param request
     * @param defaultValue
     * @return long representing the timeout present in the header or the default
     * value if the header is missing or could not be parsed.
     */
    public static TimeoutHeader parse(HttpServletRequest request, long defaultValue) {
        String timeoutStr = request.getHeader(HEADER_TIMEOUT);
        long timeout = defaultValue;
        if (timeoutStr != null && timeoutStr.length() > 0) {
            int secondsInd = timeoutStr.indexOf("Second-");
            if (secondsInd >= 0) {
                secondsInd += 7; // read over "Second-"
                int i = secondsInd;
                while (i < timeoutStr.length() && Character.isDigit(timeoutStr.charAt(i))) {
                    i++;
                }
                try {
                    timeout = 1000L * Long.parseLong(timeoutStr.substring(secondsInd, i));
                } catch (NumberFormatException ignore) {
                    // ignore and return 'undefined' timeout
                    log.error("Invalid timeout format: " + timeoutStr);
                }
            } else if (timeoutStr.equalsIgnoreCase(TIMEOUT_INFINITE)) {
                timeout = INFINITE_TIMEOUT;
            }
        }
        return new TimeoutHeader(timeout);
    }
}