FileHandler.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.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.nio.file.DirectoryStream;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.sql.Timestamp;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.logging.ErrorManager;
import java.util.logging.Filter;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.LogRecord;
import java.util.regex.Pattern;
/**
* Implementation of <b>Handler</b> that appends log messages to a file named {prefix}{date}{suffix} in a configured
* directory.
* <p>
* The following configuration properties are available:
* </p>
* <ul>
* <li><code>directory</code> - The directory where to create the log file. If the path is not absolute, it is relative
* to the current working directory of the application. The Apache Tomcat configuration files usually specify an
* absolute path for this property, <code>${catalina.base}/logs</code> Default value: <code>logs</code></li>
* <li><code>rotatable</code> - If <code>true</code>, the log file will be rotated on the first write past midnight and
* the filename will be <code>{prefix}{date}{suffix}</code>, where date is yyyy-MM-dd. If <code>false</code>, the file
* will not be rotated and the filename will be <code>{prefix}{suffix}</code>. Default value: <code>true</code></li>
* <li><code>prefix</code> - The leading part of the log file name. Default value: <code>juli.</code></li>
* <li><code>suffix</code> - The trailing part of the log file name. Default value: <code>.log</code></li>
* <li><code>bufferSize</code> - Configures buffering. The value of <code>0</code> uses system default buffering
* (typically an 8K buffer will be used). A value of <code><0</code> forces a writer flush upon each log write. A
* value <code>>0</code> uses a BufferedOutputStream with the defined value but note that the system default
* buffering will also be applied. Default value: <code>-1</code></li>
* <li><code>encoding</code> - Character set used by the log file. Default value: empty string, which means to use the
* system default character set.</li>
* <li><code>level</code> - The level threshold for this Handler. See the <code>java.util.logging.Level</code> class for
* the possible levels. Default value: <code>ALL</code></li>
* <li><code>filter</code> - The <code>java.util.logging.Filter</code> implementation class name for this Handler.
* Default value: unset</li>
* <li><code>formatter</code> - The <code>java.util.logging.Formatter</code> implementation class name for this Handler.
* Default value: <code>org.apache.juli.OneLineFormatter</code></li>
* <li><code>maxDays</code> - The maximum number of days to keep the log files. If the specified value is
* <code><=0</code> then the log files will be kept on the file system forever, otherwise they will be kept the
* specified maximum days. Default value: <code>-1</code>.</li>
* </ul>
*/
public class FileHandler extends Handler {
public static final int DEFAULT_MAX_DAYS = -1;
private static final ExecutorService DELETE_FILES_SERVICE = Executors
.newSingleThreadExecutor(new ThreadFactory("FileHandlerLogFilesCleaner-"));
// ------------------------------------------------------------ Constructor
public FileHandler() {
this(null, null, null, DEFAULT_MAX_DAYS);
}
public FileHandler(String directory, String prefix, String suffix) {
this(directory, prefix, suffix, DEFAULT_MAX_DAYS);
}
public FileHandler(String directory, String prefix, String suffix, int maxDays) {
this.directory = directory;
this.prefix = prefix;
this.suffix = suffix;
this.maxDays = maxDays;
configure();
openWriter();
clean();
}
// ----------------------------------------------------- Instance Variables
/**
* The as-of date for the currently open log file, or a zero-length string if there is no open log file.
*/
private volatile String date = "";
/**
* The directory in which log files are created.
*/
private String directory = null;
/**
* The prefix that is added to log file filenames.
*/
private String prefix = null;
/**
* The suffix that is added to log file filenames.
*/
private String suffix = null;
/**
* Determines whether the log file is rotatable
*/
private boolean rotatable = true;
/**
* Maximum number of days to keep the log files
*/
private int maxDays = DEFAULT_MAX_DAYS;
/**
* The PrintWriter to which we are currently logging, if any.
*/
private volatile PrintWriter writer = null;
/**
* Lock used to control access to the writer.
*/
protected final ReadWriteLock writerLock = new ReentrantReadWriteLock();
/**
* Log buffer size.
*/
private int bufferSize = -1;
/**
* Represents a file name pattern of type {prefix}{date}{suffix}. The date is YYYY-MM-DD
*/
private Pattern pattern;
// --------------------------------------------------------- Public Methods
/**
* Format and publish a <code>LogRecord</code>.
*
* @param record description of the log event
*/
@Override
public void publish(LogRecord record) {
if (!isLoggable(record)) {
return;
}
// Construct the timestamp we will use, if requested
Timestamp ts = new Timestamp(System.currentTimeMillis());
String tsDate = ts.toString().substring(0, 10);
writerLock.readLock().lock();
try {
// If the date has changed, switch log files
if (rotatable && !date.equals(tsDate)) {
// Upgrade to writeLock before we switch
writerLock.readLock().unlock();
writerLock.writeLock().lock();
try {
// Make sure another thread hasn't already done this
if (!date.equals(tsDate)) {
closeWriter();
date = tsDate;
openWriter();
clean();
}
} finally {
// Downgrade to read-lock. This ensures the writer remains valid
// until the log message is written
writerLock.readLock().lock();
writerLock.writeLock().unlock();
}
}
String result = null;
try {
result = getFormatter().format(record);
} catch (Exception e) {
reportError(null, e, ErrorManager.FORMAT_FAILURE);
return;
}
try {
if (writer != null) {
writer.write(result);
if (bufferSize < 0) {
writer.flush();
}
} else {
reportError("FileHandler is closed or not yet initialized, unable to log [" + result + "]", null,
ErrorManager.WRITE_FAILURE);
}
} catch (Exception e) {
reportError(null, e, ErrorManager.WRITE_FAILURE);
}
} finally {
writerLock.readLock().unlock();
}
}
// -------------------------------------------------------- Private Methods
/**
* Close the currently open log file (if any).
*/
@Override
public void close() {
closeWriter();
}
protected void closeWriter() {
writerLock.writeLock().lock();
try {
if (writer == null) {
return;
}
writer.write(getFormatter().getTail(this));
writer.flush();
writer.close();
writer = null;
date = "";
} catch (Exception e) {
reportError(null, e, ErrorManager.CLOSE_FAILURE);
} finally {
writerLock.writeLock().unlock();
}
}
/**
* Flush the writer.
*/
@Override
public void flush() {
writerLock.readLock().lock();
try {
if (writer == null) {
return;
}
writer.flush();
} catch (Exception e) {
reportError(null, e, ErrorManager.FLUSH_FAILURE);
} finally {
writerLock.readLock().unlock();
}
}
/**
* Configure from <code>LogManager</code> properties.
*/
private void configure() {
Timestamp ts = new Timestamp(System.currentTimeMillis());
date = ts.toString().substring(0, 10);
String className = this.getClass().getName(); // allow classes to override
ClassLoader cl = ClassLoaderLogManager.getClassLoader();
// Retrieve configuration of logging file name
rotatable = Boolean.parseBoolean(getProperty(className + ".rotatable", "true"));
if (directory == null) {
directory = getProperty(className + ".directory", "logs");
}
if (prefix == null) {
prefix = getProperty(className + ".prefix", "juli.");
}
if (suffix == null) {
suffix = getProperty(className + ".suffix", ".log");
}
// https://bz.apache.org/bugzilla/show_bug.cgi?id=61232
boolean shouldCheckForRedundantSeparator = !rotatable && !prefix.isEmpty() && !suffix.isEmpty();
// assuming separator is just one char, if there are use cases with
// more, the notion of separator might be introduced
if (shouldCheckForRedundantSeparator && (prefix.charAt(prefix.length() - 1) == suffix.charAt(0))) {
suffix = suffix.substring(1);
}
pattern = Pattern
.compile("^(" + Pattern.quote(prefix) + ")\\d{4}-\\d{1,2}-\\d{1,2}(" + Pattern.quote(suffix) + ")$");
String sMaxDays = getProperty(className + ".maxDays", String.valueOf(DEFAULT_MAX_DAYS));
if (maxDays <= 0) {
try {
maxDays = Integer.parseInt(sMaxDays);
} catch (NumberFormatException ignore) {
// no-op
}
}
String sBufferSize = getProperty(className + ".bufferSize", String.valueOf(bufferSize));
try {
bufferSize = Integer.parseInt(sBufferSize);
} catch (NumberFormatException ignore) {
// no op
}
// Get encoding for the logging file
String encoding = getProperty(className + ".encoding", null);
if (encoding != null && encoding.length() > 0) {
try {
setEncoding(encoding);
} catch (UnsupportedEncodingException ex) {
// Ignore
}
}
// Get logging level for the handler
setLevel(Level.parse(getProperty(className + ".level", "" + Level.ALL)));
// Get filter configuration
String filterName = getProperty(className + ".filter", null);
if (filterName != null) {
try {
setFilter((Filter) cl.loadClass(filterName).getConstructor().newInstance());
} catch (Exception e) {
// Ignore
}
}
// Set formatter
String formatterName = getProperty(className + ".formatter", null);
if (formatterName != null) {
try {
setFormatter((Formatter) cl.loadClass(formatterName).getConstructor().newInstance());
} catch (Exception e) {
// Ignore and fallback to defaults
setFormatter(new OneLineFormatter());
}
} else {
setFormatter(new OneLineFormatter());
}
// Set error manager
setErrorManager(new ErrorManager());
}
private String getProperty(String name, String defaultValue) {
String value = LogManager.getLogManager().getProperty(name);
if (value == null) {
value = defaultValue;
} else {
value = value.trim();
}
return value;
}
/**
* Open the new log file for the date specified by <code>date</code>.
*/
protected void open() {
openWriter();
}
protected void openWriter() {
// Create the directory if necessary
File dir = new File(directory);
if (!dir.mkdirs() && !dir.isDirectory()) {
reportError("Unable to create [" + dir + "]", null, ErrorManager.OPEN_FAILURE);
writer = null;
return;
}
// Open the current log file
writerLock.writeLock().lock();
FileOutputStream fos = null;
OutputStream os = null;
try {
File pathname = new File(dir.getAbsoluteFile(), prefix + (rotatable ? date : "") + suffix);
File parent = pathname.getParentFile();
if (!parent.mkdirs() && !parent.isDirectory()) {
reportError("Unable to create [" + parent + "]", null, ErrorManager.OPEN_FAILURE);
writer = null;
return;
}
String encoding = getEncoding();
fos = new FileOutputStream(pathname, true);
os = bufferSize > 0 ? new BufferedOutputStream(fos, bufferSize) : fos;
writer = new PrintWriter(
(encoding != null) ? new OutputStreamWriter(os, encoding) : new OutputStreamWriter(os), false);
writer.write(getFormatter().getHead(this));
} catch (Exception e) {
reportError(null, e, ErrorManager.OPEN_FAILURE);
writer = null;
if (fos != null) {
try {
fos.close();
} catch (IOException e1) {
// Ignore
}
}
if (os != null) {
try {
os.close();
} catch (IOException e1) {
// Ignore
}
}
} finally {
writerLock.writeLock().unlock();
}
}
private void clean() {
if (maxDays <= 0 || Files.notExists(getDirectoryAsPath())) {
return;
}
DELETE_FILES_SERVICE.submit(new Runnable() {
@Override
public void run() {
try (DirectoryStream<Path> files = streamFilesForDelete()) {
for (Path file : files) {
Files.delete(file);
}
} catch (IOException e) {
reportError("Unable to delete log files older than [" + maxDays + "] days", null,
ErrorManager.GENERIC_FAILURE);
}
}
});
}
private DirectoryStream<Path> streamFilesForDelete() throws IOException {
final Date maxDaysOffset = getMaxDaysOffset();
final SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
return Files.newDirectoryStream(getDirectoryAsPath(), new DirectoryStream.Filter<Path>() {
@Override
public boolean accept(Path path) throws IOException {
boolean result = false;
String date = obtainDateFromPath(path);
if (date != null) {
try {
Date dateFromFile = formatter.parse(date);
result = dateFromFile.before(maxDaysOffset);
} catch (ParseException e) {
// no-op
}
}
return result;
}
});
}
private Path getDirectoryAsPath() {
return FileSystems.getDefault().getPath(directory);
}
private String obtainDateFromPath(Path path) {
Path fileName = path.getFileName();
if (fileName == null) {
return null;
}
String date = fileName.toString();
if (pattern.matcher(date).matches()) {
date = date.substring(prefix.length());
return date.substring(0, date.length() - suffix.length());
} else {
return null;
}
}
private Date getMaxDaysOffset() {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
cal.add(Calendar.DATE, -maxDays);
return cal.getTime();
}
protected static final class ThreadFactory implements java.util.concurrent.ThreadFactory {
private final String namePrefix;
private final boolean isSecurityEnabled;
private final ThreadGroup group;
private final AtomicInteger threadNumber = new AtomicInteger(1);
public ThreadFactory(final String namePrefix) {
this.namePrefix = namePrefix;
SecurityManager s = System.getSecurityManager();
if (s == null) {
this.isSecurityEnabled = false;
this.group = Thread.currentThread().getThreadGroup();
} else {
this.isSecurityEnabled = true;
this.group = s.getThreadGroup();
}
}
@Override
public Thread newThread(Runnable r) {
final Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement());
// Threads should not have as context classloader a webapp classloader
if (isSecurityEnabled) {
AccessController.doPrivileged(new PrivilegedAction<Void>() {
@Override
public Void run() {
t.setContextClassLoader(ThreadFactory.class.getClassLoader());
return null;
}
});
} else {
t.setContextClassLoader(ThreadFactory.class.getClassLoader());
}
t.setDaemon(true);
return t;
}
}
}