/** * Copyright 2005 The Apache Software Foundation * * 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 org.apache.hadoop.util;import java.util.logging.*;import java.io.*;import java.text.*;import java.util.Date;/** Prints just the date and the log message. */public class LogFormatter extends Formatter {  private static final String FORMAT = "yyMMdd HHmmss";  private static final String NEWLINE = System.getProperty("line.separator");  private final Date date = new Date();  private final SimpleDateFormat formatter = new SimpleDateFormat(FORMAT);  private static boolean loggedSevere= false;  private static boolean showTime = true;  private static boolean showThreadIDs = false;  // install when this class is loaded  static {    Handler[] handlers = LogFormatter.getLogger("").getHandlers();    for (int i = 0; i < handlers.length; i++) {      handlers[i].setFormatter(new LogFormatter());      handlers[i].setLevel(Level.FINEST);    }  }  /** Gets a logger and, as a side effect, installs this as the default   * formatter. */  public static Logger getLogger(String name) {    // just referencing this class installs it    return Logger.getLogger(name);  }    /** When true, time is logged with each entry. */  public static void showTime(boolean showTime) {    LogFormatter.showTime = showTime;  }  /** When set true, thread IDs are logged. */  public static void setShowThreadIDs(boolean showThreadIDs) {    LogFormatter.showThreadIDs = showThreadIDs;  }  /**   * Format the given LogRecord.   * @param record the log record to be formatted.   * @return a formatted log record   */  public synchronized String format(LogRecord record) {    StringBuffer buffer = new StringBuffer();    // the date    if (showTime) {      date.setTime(record.getMillis());      formatter.format(date, buffer, new FieldPosition(0));    }        // the thread id    if (showThreadIDs) {      buffer.append(" ");      buffer.append(record.getThreadID());    }    // handle SEVERE specially    if (record.getLevel() == Level.SEVERE) {      buffer.append(" SEVERE");                   // flag it in log      loggedSevere= true;                         // set global flag    }    // the message    buffer.append(" ");    buffer.append(formatMessage(record));    buffer.append(NEWLINE);    if (record.getThrown() != null) {      try {        StringWriter sw = new StringWriter();        PrintWriter pw = new PrintWriter(sw);        record.getThrown().printStackTrace(pw);        pw.close();        buffer.append(sw.toString());      } catch (Exception ex) {      }    }    return buffer.toString();  }  /**   * Returns <code>true</code> if this <code>LogFormatter</code> has   * logged something at <code>Level.SEVERE</code>   */  public static boolean hasLoggedSevere() {    return loggedSevere;  }  /** Returns a stream that, when written to, adds log lines. */  public static PrintStream getLogStream(final Logger logger,                                         final Level level) {    return new PrintStream(new ByteArrayOutputStream() {        private int scan = 0;        private boolean hasNewline() {          for (; scan < count; scan++) {            if (buf[scan] == '\n')              return true;          }          return false;        }        public void flush() throws IOException {          if (!hasNewline())            return;          logger.log(level, toString().trim());          reset();          scan = 0;        }      }, true);  }}