chapters.appenders.CountingConsoleAppender Maven / Gradle / Ivy

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/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package chapters.appenders;

import java.io.IOException;

import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.AppenderBase;

public class CountingConsoleAppender extends AppenderBase {
    static int DEFAULT_LIMIT = 10;
    int counter = 0;
    int limit = DEFAULT_LIMIT;

    PatternLayoutEncoder encoder;

    public void setLimit(int limit) {
        this.limit = limit;
    }

    public int getLimit() {
        return limit;
    }

    @Override
    public void start() {
        if (this.encoder == null) {
            addError("No encoder set for the appender named [" + name + "].");
            return;
        }

        try {
            encoder.init(System.out);
        } catch (IOException e) {
        }
        super.start();
    }

    public void append(ILoggingEvent event) {
        if (counter >= limit) {
            return;
        }
        // output the events as formatted by the wrapped layout
        try {
            this.encoder.doEncode(event);
        } catch (IOException e) {
        }

        // prepare for next event
        counter++;
    }

    public PatternLayoutEncoder getEncoder() {
        return encoder;
    }

    public void setEncoder(PatternLayoutEncoder encoder) {
        this.encoder = encoder;
    }
}