DirectoryWatcher.java

/**
 * Licensed to the Austrian Association for Software Tool Integration (AASTI)
 * under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership. The AASTI 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 org.openengsb.connector.virtual.filewatcher.internal;

import java.io.File;
import java.util.TimerTask;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class DirectoryWatcher extends TimerTask {

    private static final Logger LOGGER = LoggerFactory.getLogger(DirectoryWatcher.class);

    protected File watchfile;

    private long lastmodified;

    public DirectoryWatcher(File watchfile) {
        this.watchfile = watchfile;
        lastmodified = 0;
    }

    @Override
    public void run() {
        LOGGER.debug("polling file " + watchfile);
        long lm = watchfile.lastModified();
        if (lm == lastmodified) {
            return;
        }
        lastmodified = lm;
        onFileModified();
    }

    protected abstract void onFileModified();

}