File	Doc	Category	Size	Date	Package
FileHandler.java	API Doc	Java SE 5 API	20397	Fri Aug 26 14:57:26 BST 2005	java.util.logging

FileHandler

• java.lang.Object
  • java.util.logging.Handler
    • java.util.logging.StreamHandler

Fields Summary
private MeteredStream	meter
private boolean	append
private int	limit
private int	count
private String	pattern
private String	lockFileName
private FileOutputStream	lockStream
private File[]	files
private static final int	MAX_LOCKS
private static HashMap	locks

Constructors Summary
public FileHandler() Construct a default FileHandler. This will be configured entirely from LogManager properties (or their default values). exception IOException if there are IO problems opening the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control")). exception NullPointerException if pattern property is an empty String. checkAccess(); configure(); openFiles();
public FileHandler(String pattern) Initialize a FileHandler to write to the given filename. The FileHandler is configured based on LogManager properties (or their default values) except that the given pattern argument is used as the filename pattern, the file limit is set to no limit, and the file count is set to one. There is no limit on the amount of data that may be written, so use this with care. param pattern the name of the output file exception IOException if there are IO problems opening the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). exception IllegalArgumentException if pattern is an empty string if (pattern.length() < 1 ) { throw new IllegalArgumentException(); } checkAccess(); configure(); this.pattern = pattern; this.limit = 0; this.count = 1; openFiles();
public FileHandler(String pattern, boolean append) Initialize a FileHandler to write to the given filename, with optional append. The FileHandler is configured based on LogManager properties (or their default values) except that the given pattern argument is used as the filename pattern, the file limit is set to no limit, the file count is set to one, and the append mode is set to the given append argument. There is no limit on the amount of data that may be written, so use this with care. param pattern the name of the output file param append specifies append mode exception IOException if there are IO problems opening the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). exception IllegalArgumentException if pattern is an empty string if (pattern.length() < 1 ) { throw new IllegalArgumentException(); } checkAccess(); configure(); this.pattern = pattern; this.limit = 0; this.count = 1; this.append = append; openFiles();
public FileHandler(String pattern, int limit, int count) Initialize a FileHandler to write to a set of files. When (approximately) the given limit has been written to one file, another file will be opened. The output will cycle through a set of count files. The FileHandler is configured based on LogManager properties (or their default values) except that the given pattern argument is used as the filename pattern, the file limit is set to the limit argument, and the file count is set to the given count argument. The count must be at least 1. param pattern the pattern for naming the output file param limit the maximum number of bytes to write to any one file param count the number of files to use exception IOException if there are IO problems opening the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). exception IllegalArgumentException if limit < 0, or count < 1. exception IllegalArgumentException if pattern is an empty string if (limit < 0 || count < 1 || pattern.length() < 1) { throw new IllegalArgumentException(); } checkAccess(); configure(); this.pattern = pattern; this.limit = limit; this.count = count; openFiles();
public FileHandler(String pattern, int limit, int count, boolean append) Initialize a FileHandler to write to a set of files with optional append. When (approximately) the given limit has been written to one file, another file will be opened. The output will cycle through a set of count files. The FileHandler is configured based on LogManager properties (or their default values) except that the given pattern argument is used as the filename pattern, the file limit is set to the limit argument, and the file count is set to the given count argument, and the append mode is set to the given append argument. The count must be at least 1. param pattern the pattern for naming the output file param limit the maximum number of bytes to write to any one file param count the number of files to use param append specifies append mode exception IOException if there are IO problems opening the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). exception IllegalArgumentException if limit < 0, or count < 1. exception IllegalArgumentException if pattern is an empty string if (limit < 0 || count < 1 || pattern.length() < 1) { throw new IllegalArgumentException(); } checkAccess(); configure(); this.pattern = pattern; this.limit = limit; this.count = count; this.append = append; openFiles();

Methods Summary
public synchronized void	close() Close all the files. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). super.close(); // Unlock any lock file. if (lockFileName == null) { return; } try { // Closing the lock file's FileOutputStream will close // the underlying channel and free any locks. lockStream.close(); } catch (Exception ex) { // Problems closing the stream. Punt. } synchronized(locks) { locks.remove(lockFileName); } new File(lockFileName).delete(); lockFileName = null; lockStream = null;
private void	configure() LogManager manager = LogManager.getLogManager(); String cname = getClass().getName(); pattern = manager.getStringProperty(cname + ".pattern", "%h/java%u.log"); limit = manager.getIntProperty(cname + ".limit", 0); if (limit < 0) { limit = 0; } count = manager.getIntProperty(cname + ".count", 1); if (count <= 0) { count = 1; } append = manager.getBooleanProperty(cname + ".append", false); setLevel(manager.getLevelProperty(cname + ".level", Level.ALL)); setFilter(manager.getFilterProperty(cname + ".filter", null)); setFormatter(manager.getFormatterProperty(cname + ".formatter", new XMLFormatter())); try { setEncoding(manager.getStringProperty(cname +".encoding", null)); } catch (Exception ex) { try { setEncoding(null); } catch (Exception ex2) { // doing a setEncoding with null should always work. // assert false; } }
private java.io.File	generate(java.lang.String pattern, int generation, int unique) File file = null; String word = ""; int ix = 0; boolean sawg = false; boolean sawu = false; while (ix < pattern.length()) { char ch = pattern.charAt(ix); ix++; char ch2 = 0; if (ix < pattern.length()) { ch2 = Character.toLowerCase(pattern.charAt(ix)); } if (ch == '/") { if (file == null) { file = new File(word); } else { file = new File(file, word); } word = ""; continue; } else if (ch == '%") { if (ch2 == 't") { String tmpDir = System.getProperty("java.io.tmpdir"); if (tmpDir == null) { tmpDir = System.getProperty("user.home"); } file = new File(tmpDir); ix++; word = ""; continue; } else if (ch2 == 'h") { file = new File(System.getProperty("user.home")); if (isSetUID()) { // Ok, we are in a set UID program. For safety's sake // we disallow attempts to open files relative to %h. throw new IOException("can't use %h in set UID program"); } ix++; word = ""; continue; } else if (ch2 == 'g") { word = word + generation; sawg = true; ix++; continue; } else if (ch2 == 'u") { word = word + unique; sawu = true; ix++; continue; } else if (ch2 == '%") { word = word + "%"; ix++; continue; } } word = word + ch; } if (count > 1 && !sawg) { word = word + "." + generation; } if (unique > 0 && !sawu) { word = word + "." + unique; } if (word.length() > 0) { if (file == null) { file = new File(word); } else { file = new File(file, word); } } return file;
private static native boolean	isSetUID()
private void	open(java.io.File fname, boolean append) int len = 0; if (append) { len = (int)fname.length(); } FileOutputStream fout = new FileOutputStream(fname.toString(), append); BufferedOutputStream bout = new BufferedOutputStream(fout); meter = new MeteredStream(bout, len); setOutputStream(meter);
private void	openFiles() LogManager manager = LogManager.getLogManager(); manager.checkAccess(); if (count < 1) { throw new IllegalArgumentException("file count = " + count); } if (limit < 0) { limit = 0; } // We register our own ErrorManager during initialization // so we can record exceptions. InitializationErrorManager em = new InitializationErrorManager(); setErrorManager(em); // Create a lock file. This grants us exclusive access // to our set of output files, as long as we are alive. int unique = -1; for (;;) { unique++; if (unique > MAX_LOCKS) { throw new IOException("Couldn't get lock for " + pattern); } // Generate a lock file name from the "unique" int. lockFileName = generate(pattern, 0, unique).toString() + ".lck"; // Now try to lock that filename. // Because some systems (e.g. Solaris) can only do file locks // between processes (and not within a process), we first check // if we ourself already have the file locked. synchronized(locks) { if (locks.get(lockFileName) != null) { // We already own this lock, for a different FileHandler // object. Try again. continue; } FileChannel fc; try { lockStream = new FileOutputStream(lockFileName); fc = lockStream.getChannel(); } catch (IOException ix) { // We got an IOException while trying to open the file. // Try the next file. continue; } try { FileLock fl = fc.tryLock(); if (fl == null) { // We failed to get the lock. Try next file. continue; } // We got the lock OK. } catch (IOException ix) { // We got an IOException while trying to get the lock. // This normally indicates that locking is not supported // on the target directory. We have to proceed without // getting a lock. Drop through. } // We got the lock. Remember it. locks.put(lockFileName, lockFileName); break; } } files = new File[count]; for (int i = 0; i < count; i++) { files[i] = generate(pattern, i, unique); } // Create the initial log file. if (append) { open(files[0], true); } else { rotate(); } // Did we detect any exceptions during initialization? Exception ex = em.lastException; if (ex != null) { if (ex instanceof IOException) { throw (IOException) ex; } else if (ex instanceof SecurityException) { throw (SecurityException) ex; } else { throw new IOException("Exception: " + ex); } } // Install the normal default ErrorManager. setErrorManager(new ErrorManager());
public synchronized void	publish(java.util.logging.LogRecord record) Format and publish a LogRecord. param record description of the log event. A null record is silently ignored and is not published if (!isLoggable(record)) { return; } super.publish(record); flush(); if (limit > 0 && meter.written >= limit) { // We performed access checks in the "init" method to make sure // we are only initialized from trusted code. So we assume // it is OK to write the target files, even if we are // currently being called from untrusted code. // So it is safe to raise privilege here. AccessController.doPrivileged(new PrivilegedAction() { public Object run() { rotate(); return null; } }); }
private synchronized void	rotate() Level oldLevel = getLevel(); setLevel(Level.OFF); super.close(); for (int i = count-2; i >= 0; i--) { File f1 = files[i]; File f2 = files[i+1]; if (f1.exists()) { if (f2.exists()) { f2.delete(); } f1.renameTo(f2); } } try { open(files[0], false); } catch (IOException ix) { // We don't want to throw an exception here, but we // report the exception to any registered ErrorManager. reportError(null, ix, ErrorManager.OPEN_FAILURE); } setLevel(oldLevel);