org.opentcs.util.logging.SingleLineFormatter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of opentcs-common Show documentation
openTCS-Common
The newest version!
// SPDX-FileCopyrightText: The openTCS Authors
// SPDX-License-Identifier: MIT
package org.opentcs.util.logging;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.Formatter;
import java.util.logging.LogRecord;

/**
 * A Formatter for LogRecords that formats messages
 * for output on a single line (except when a Throwable is
 * associated with the LogRecord.
 */
public class SingleLineFormatter
    extends
      Formatter {

  /**
   * A DateFormat instance for formatting timestamps.
   */
  private static final DateFormat DATE_FORMAT = new SimpleDateFormat("yyyyMMdd-HH:mm:ss-SSS");
  /**
   * A Date instance for formatting timestamps.
   */
  private final Date date = new Date();
  /**
   * Line separator for wrapping lines at the end of log messages.
   */
  private final String lineSeparator = System.getProperty("line.separator");

  /**
   * Creates a new SingleLineFormatter.
   */
  public SingleLineFormatter() {
  }

  @Override
  public synchronized String format(LogRecord record) {
    date.setTime(record.getMillis());
    StringBuilder result = new StringBuilder();

    result.append('[')
        .append(DATE_FORMAT.format(date))
        .append("] ")
        .append(String.format("%1$-7.7s", record.getLevel().getName()))
        .append(' ')
        .append(String.format("%1$-20s", Thread.currentThread().getName()))
        .append(' ')
        .append(String.format("%1$-55s", source(record)))
        .append(": ")
        .append(formatMessage(record))
        .append(lineSeparator);

    if (record.getThrown() != null) {
      result.append(stackTrace(record.getThrown()));
      result.append(lineSeparator);
    }

    return result.toString();
  }

  private String source(LogRecord record) {
    return record.getSourceClassName() != null
        ? record.getSourceClassName()
            .replaceAll("\\B\\w+(\\.[a-z])", "$1") + "." + record.getSourceMethodName() + "()"
        : record.getLoggerName();
  }

  private String stackTrace(Throwable thrown) {
    try (StringWriter sWriter = new StringWriter();
         PrintWriter pWriter = new PrintWriter(sWriter)) {
      thrown.printStackTrace(pWriter);
      pWriter.flush();
      return sWriter.toString();
    }
    catch (IOException exc) {
      throw new IllegalStateException("Could not print stack trace for log output", exc);
    }
  }
}