OneLineFormatter.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.juli;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.logging.Formatter;
import java.util.logging.LogManager;
import java.util.logging.LogRecord;
/**
* Provides same information as default log format but on a single line to make it easier to grep the logs. The only
* exception is stacktraces which are always preceded by whitespace to make it simple to skip them.
*/
/*
* Date processing based on AccessLogValve.
*/
public class OneLineFormatter extends Formatter {
private static final String UNKNOWN_THREAD_NAME = "Unknown thread with ID ";
private static final Object threadMxBeanLock = new Object();
private static volatile ThreadMXBean threadMxBean = null;
private static final int THREAD_NAME_CACHE_SIZE = 10000;
private static final ThreadLocal<ThreadNameCache> threadNameCache = ThreadLocal
.withInitial(() -> new ThreadNameCache(THREAD_NAME_CACHE_SIZE));
/* Timestamp format */
private static final String DEFAULT_TIME_FORMAT = "dd-MMM-yyyy HH:mm:ss.SSS";
/**
* The size of our global date format cache
*/
private static final int globalCacheSize = 30;
/**
* The size of our thread local date format cache
*/
private static final int localCacheSize = 5;
/**
* Thread local date format cache.
*/
private ThreadLocal<DateFormatCache> localDateCache;
private volatile MillisHandling millisHandling = MillisHandling.APPEND;
public OneLineFormatter() {
String timeFormat = LogManager.getLogManager().getProperty(OneLineFormatter.class.getName() + ".timeFormat");
if (timeFormat == null) {
timeFormat = DEFAULT_TIME_FORMAT;
}
setTimeFormat(timeFormat);
}
/**
* Specify the time format to use for time stamps in log messages.
*
* @param timeFormat The format to use using the {@link java.text.SimpleDateFormat} syntax
*/
public void setTimeFormat(final String timeFormat) {
final String cachedTimeFormat;
if (timeFormat.endsWith(".SSS")) {
cachedTimeFormat = timeFormat.substring(0, timeFormat.length() - 4);
millisHandling = MillisHandling.APPEND;
} else if (timeFormat.contains("SSS")) {
millisHandling = MillisHandling.REPLACE_SSS;
cachedTimeFormat = timeFormat;
} else if (timeFormat.contains("SS")) {
millisHandling = MillisHandling.REPLACE_SS;
cachedTimeFormat = timeFormat;
} else if (timeFormat.contains("S")) {
millisHandling = MillisHandling.REPLACE_S;
cachedTimeFormat = timeFormat;
} else {
millisHandling = MillisHandling.NONE;
cachedTimeFormat = timeFormat;
}
final DateFormatCache globalDateCache = new DateFormatCache(globalCacheSize, cachedTimeFormat, null);
localDateCache = ThreadLocal
.withInitial(() -> new DateFormatCache(localCacheSize, cachedTimeFormat, globalDateCache));
}
/**
* Obtain the format currently being used for time stamps in log messages.
*
* @return The current format in {@link java.text.SimpleDateFormat} syntax
*/
public String getTimeFormat() {
return localDateCache.get().getTimeFormat();
}
@Override
public String format(LogRecord record) {
StringBuilder sb = new StringBuilder();
// Timestamp
addTimestamp(sb, record.getMillis());
// Severity
sb.append(' ');
sb.append(record.getLevel().getLocalizedName());
// Thread
sb.append(' ');
sb.append('[');
final String threadName = Thread.currentThread().getName();
if (threadName != null && threadName.startsWith(AsyncFileHandler.THREAD_PREFIX)) {
// If using the async handler can't get the thread name from the
// current thread.
sb.append(getThreadName(record.getThreadID()));
} else {
sb.append(threadName);
}
sb.append(']');
// Source
sb.append(' ');
sb.append(record.getSourceClassName());
sb.append('.');
sb.append(record.getSourceMethodName());
// Message
sb.append(' ');
sb.append(formatMessage(record));
// New line for next record
sb.append(System.lineSeparator());
// Stack trace
if (record.getThrown() != null) {
StringWriter sw = new StringWriter();
PrintWriter pw = new IndentingPrintWriter(sw);
record.getThrown().printStackTrace(pw);
pw.close();
sb.append(sw.getBuffer());
}
return sb.toString();
}
protected void addTimestamp(StringBuilder buf, long timestamp) {
String cachedTimeStamp = localDateCache.get().getFormat(timestamp);
if (millisHandling == MillisHandling.NONE) {
buf.append(cachedTimeStamp);
} else if (millisHandling == MillisHandling.APPEND) {
buf.append(cachedTimeStamp);
long frac = timestamp % 1000;
buf.append('.');
if (frac < 100) {
if (frac < 10) {
buf.append('0');
buf.append('0');
} else {
buf.append('0');
}
}
buf.append(frac);
} else {
// Some version of replace
long frac = timestamp % 1000;
// Formatted string may vary in length so the insert point may vary
int insertStart = cachedTimeStamp.indexOf(DateFormatCache.MSEC_PATTERN);
buf.append(cachedTimeStamp.subSequence(0, insertStart));
if (frac < 100 && millisHandling == MillisHandling.REPLACE_SSS) {
buf.append('0');
if (frac < 10) {
buf.append('0');
}
} else if (frac < 10 && millisHandling == MillisHandling.REPLACE_SS) {
buf.append('0');
}
buf.append(frac);
if (millisHandling == MillisHandling.REPLACE_SSS) {
buf.append(cachedTimeStamp.substring(insertStart + 3));
} else if (millisHandling == MillisHandling.REPLACE_SS) {
buf.append(cachedTimeStamp.substring(insertStart + 2));
} else {
buf.append(cachedTimeStamp.substring(insertStart + 1));
}
}
}
/**
* LogRecord has threadID but no thread name. LogRecord uses an int for thread ID but thread IDs are longs. If the
* real thread ID > (Integer.MAXVALUE / 2) LogRecord uses it's own ID in an effort to avoid clashes due to overflow.
* <p>
* Words fail me to describe what I think of the design decision to use an int in LogRecord for a long value and the
* resulting mess that follows.
*/
private static String getThreadName(int logRecordThreadId) {
Map<Integer, String> cache = threadNameCache.get();
String result = cache.get(Integer.valueOf(logRecordThreadId));
if (result != null) {
return result;
}
if (logRecordThreadId > Integer.MAX_VALUE / 2) {
result = UNKNOWN_THREAD_NAME + logRecordThreadId;
} else {
// Double checked locking OK as threadMxBean is volatile
if (threadMxBean == null) {
synchronized (threadMxBeanLock) {
if (threadMxBean == null) {
threadMxBean = ManagementFactory.getThreadMXBean();
}
}
}
ThreadInfo threadInfo = threadMxBean.getThreadInfo(logRecordThreadId);
if (threadInfo == null) {
return Long.toString(logRecordThreadId);
}
result = threadInfo.getThreadName();
}
cache.put(Integer.valueOf(logRecordThreadId), result);
return result;
}
/*
* This is an LRU cache.
*/
private static class ThreadNameCache extends LinkedHashMap<Integer, String> {
private static final long serialVersionUID = 1L;
private final int cacheSize;
ThreadNameCache(int cacheSize) {
super(cacheSize, 0.75f, true);
this.cacheSize = cacheSize;
}
@Override
protected boolean removeEldestEntry(Map.Entry<Integer, String> eldest) {
return (size() > cacheSize);
}
}
/*
* Minimal implementation to indent the printing of stack traces. This implementation depends on Throwable using
* WrappedPrintWriter.
*/
private static class IndentingPrintWriter extends PrintWriter {
IndentingPrintWriter(Writer out) {
super(out);
}
@Override
public void println(Object x) {
super.print('\t');
super.println(x);
}
}
private enum MillisHandling {
NONE, APPEND, REPLACE_S, REPLACE_SS, REPLACE_SSS,
}
}