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Aspectran module showcasing a demo application

There is a newer version: 8.2.0

/*
 * Copyright (c) 2008-2020 The Aspectran Project
 *
 * 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 com.aspectran.demo.apm.log;

import com.aspectran.core.util.lifecycle.AbstractLifeCycle;
import org.apache.commons.io.input.Tailer;
import org.apache.commons.io.input.TailerListener;

import java.io.File;

public class LogTailer extends AbstractLifeCycle {

    private static final long DEFAULT_SAMPLE_INTERVAL = 1000;

    private final String name;

    /** the log file to tail */
    private final String logFile;

    /** how frequently to check for file changes; defaults to 1 second */
    private final long sampleInterval;

    private TailerListener tailerListener;

    private Tailer tailer;

    public LogTailer(String name, String logFile) {
        this(name, logFile, DEFAULT_SAMPLE_INTERVAL);
    }

    public LogTailer(String name, String logFile, long sampleInterval) {
        this.name = name;
        this.logFile = logFile;
        this.sampleInterval = sampleInterval;
    }

    public String getName() {
        return name;
    }

    public void setEndpoint(LogtailEndpoint endpoint) {
        this.tailerListener = new LogTailerListener(name, endpoint);
    }

    protected void doStart() throws Exception {
        if (tailerListener == null) {
            throw new IllegalStateException("No TailerListener configured");
        }
        tailer = Tailer.create(new File(logFile), tailerListener, sampleInterval, true);
    }

    protected void doStop() throws Exception {
        if (tailer != null) {
            tailer.stop();
            tailer = null;
        }
    }

}