Android Open Source - AndroidAppLog Rolling File Appender

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Back to project page AndroidAppLog.

License

The source code is released under:

Apache License

If you think the Android project AndroidAppLog listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

package me.allenz.androidapplog;
// www.j av a 2 s  . co  m
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RollingFileAppender extends AsyncAppender {

  private static final byte[] LINE_BREAK_BYTES = "\n".getBytes();

  private File logDir;

  private String packageName;

  private int rolling;

  private long rollSize;

  private boolean useGZip;

  private File logFile;

  private FileOutputStream out;

  public RollingFileAppender(final File logDir, final long rollSize,
      final boolean useGZip) {
    this.logDir = logDir;
    this.rollSize = rollSize;
    this.useGZip = useGZip;
    packageName = LoggerFactory.getPackageName();
  }

  @Override
  protected boolean doStart() {
    final boolean created = createLogDir();
    if (!created) {
      LoggerFactory.getInternalLogger().verbose(
          "can not create folder %s", logDir.getPath());
      return false;
    }
    rolling = getRollingNumber();
    logFile = getLogFile(rolling);
    try {
      out = createOrOpenLogFile(logFile);
    } catch (final IOException e) {
      e.printStackTrace();
    }
    return super.doStart();
  }

  @Override
  protected boolean doStop() {
    try {
      out.close();
    } catch (final IOException e) {
    }
    return super.doStop();
  }

  private boolean createLogDir() {
    if (!logDir.exists()) {
      return logDir.mkdirs();
    }
    return true;
  }

  private int getRollingNumber() {
    final Pattern fileNamePattern = Pattern.compile("^"
        + packageName.replace(".", "\\.").replace("$", "\\$")
        + "(\\.(\\d+))?\\.log(\\.gz)?$");
    int number = 0;
    final File[] logFiles = logDir.listFiles();
    for (int i = 0; i < logFiles.length; i++) {
      final String logFileName = logFiles[i].getName();
      final Matcher matcher = fileNamePattern.matcher(logFileName);
      if (matcher.find()) {
        try {
          final Integer currentNumber = Integer.valueOf(matcher
              .group(2));
          if (number < currentNumber) {
            number = currentNumber;
          }
        } catch (final NumberFormatException e) {
        }
      }
    }
    return number;
  }

  private File getLogFile(final int rolling) {
    String logFilename = packageName;
    if (rolling > 0) {
      logFilename += "." + rolling;
    }
    logFilename += ".log";
    return new File(logDir, logFilename);
  }

  private FileOutputStream createOrOpenLogFile(final File logFile)
      throws IOException {
    if (!logFile.exists()) {
      logFile.createNewFile();
      return new FileOutputStream(logFile);
    } else {
      return new FileOutputStream(logFile, true);
    }
  }

  @Override
  protected void handleEventQueue() throws InterruptedException {
    try {
      final LogEvent event = logEventQueue.take();
      final byte[] logBytes = event.toString().getBytes();
      if (!logFile.exists()) {
        out.close();
        out = createOrOpenLogFile(logFile);
      }
      final long logFileSize = out.getChannel().size();
      if (logFileSize + logBytes.length > rollSize) {
        out.close();
        if (useGZip) {
          Runtime.getRuntime().exec("gzip " + logFile.getPath());
        }
        rolling++;
        logFile = getLogFile(rolling);
        out = createOrOpenLogFile(logFile);
      }
      out.write(logBytes);
      out.write(LINE_BREAK_BYTES);
      out.flush();
      out.getFD().sync();
    } catch (final IOException e) {
      e.printStackTrace();
    }
  }
}

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