org.eclipse.scada.protocol.syslog.time.PatternTimestampParser.java Source code

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Here is the source code for org.eclipse.scada.protocol.syslog.time.PatternTimestampParser.java

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/*******************************************************************************
 * Copyright (c) 2014 IBH SYSTEMS GmbH and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBH SYSTEMS GmbH - initial API and implementation
 *******************************************************************************/
package org.eclipse.scada.protocol.syslog.time;

import io.netty.buffer.ByteBuf;
import io.netty.handler.codec.CodecException;

import java.nio.charset.Charset;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

public class PatternTimestampParser implements TimestampParser {
    private final static Logger logger = LoggerFactory.getLogger(PatternTimestampParser.class);

    private final Pattern pattern;

    private final byte endMarker;

    private final Charset charset;

    public PatternTimestampParser(final Pattern pattern, final byte endMarker, final Charset charset) {
        this.pattern = pattern;
        this.endMarker = endMarker;
        this.charset = charset;
    }

    @Override
    public Calendar parseTimestamp(final ByteBuf data) {
        final int index = data.bytesBefore(this.endMarker);
        if (index < 0) {
            throw new CodecException("Unable to find timestamp");
        }

        final String timestampString = data.readSlice(index).toString(this.charset);

        logger.debug("Timestamp string: '{}'", timestampString);

        final Matcher m = this.pattern.matcher(timestampString);
        if (!m.matches()) {
            throw new CodecException("Timestamp string does not match pattern: " + this.pattern.pattern());
        }

        final int year = Integer.parseInt(m.group("year"));
        final int month = Integer.parseInt(m.group("month")) - 1;
        final int day = Integer.parseInt(m.group("day"));
        final int hour = Integer.parseInt(m.group("hour"));
        final int minute = Integer.parseInt(m.group("minute"));
        final int second = Integer.parseInt(m.group("second"));
        final int ms = Integer.parseInt(m.group("subsec")) / 1000;

        TimeZone timezone = TimeZone.getDefault();
        final String tz = m.group("tz");
        if (!tz.isEmpty()) {
            // FIXME: implement
            if ("Z".equals(tz)) {
                timezone = TimeZone.getTimeZone("UTC");
            } else {
                timezone = TimeZone.getTimeZone("GMT" + tz);
            }
        }

        final Calendar c = new GregorianCalendar(year, month, day, hour, minute, second);
        c.setTimeZone(timezone);
        c.set(Calendar.MILLISECOND, ms);

        // skip marker byte
        data.skipBytes(1);

        return c;
    }

}