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YAJSW is a java centric implementation of the java service wrapper by tanuki (JSW). It aims at being mostly configuration compliant with the original. It should therefore be easy to switch from JSW to YAJSW.

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package org.rzo.yajsw.log;

/*
 * @(#)FileHandler.java	1.37 10/03/23
 *
 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

import java.io.*;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.security.*;
import java.util.LinkedList;
import java.util.logging.ErrorManager;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.LogRecord;
import java.util.logging.StreamHandler;

/**
 * Simple file logging Handler.
 * 

* The FileHandler can either write to a specified file, * or it can write to a rotating set of files. *

* For a rotating set of files, as each file reaches a given size * limit, it is closed, rotated out, and a new file opened. * Successively older files are named by adding "0", "1", "2", * etc into the base filename. *

* By default buffering is enabled in the IO libraries but each log * record is flushed out when it is complete. *

* By default the XMLFormatter class is used for formatting. *

* Configuration: * By default each FileHandler is initialized using the following * LogManager configuration properties. If properties are not defined * (or have invalid values) then the specified default values are used. *

    *
  • java.util.logging.FileHandler.level * specifies the default level for the Handler * (defaults to Level.ALL). *
  • java.util.logging.FileHandler.filter * specifies the name of a Filter class to use * (defaults to no Filter). *
  • java.util.logging.FileHandler.formatter * specifies the name of a Formatter class to use * (defaults to java.util.logging.XMLFormatter) *
  • java.util.logging.FileHandler.encoding * the name of the character set encoding to use (defaults to * the default platform encoding). *
  • java.util.logging.FileHandler.limit * specifies an approximate maximum amount to write (in bytes) * to any one file. If this is zero, then there is no limit. * (Defaults to no limit). *
  • java.util.logging.FileHandler.count * specifies how many output files to cycle through (defaults to 1). *
  • java.util.logging.FileHandler.pattern * specifies a pattern for generating the output file name. See * below for details. (Defaults to "%h/java%u.log"). *
  • java.util.logging.FileHandler.append * specifies whether the FileHandler should append onto * any existing files (defaults to false). *
*

*

* A pattern consists of a string that includes the following special * components that will be replaced at runtime: *

    *
  • "/" the local pathname separator *
  • "%t" the system temporary directory *
  • "%h" the value of the "user.home" system property *
  • "%g" the generation number to distinguish rotated logs *
  • "%u" a unique number to resolve conflicts *
  • "%%" translates to a single percent sign "%" *
* If no "%g" field has been specified and the file count is greater * than one, then the generation number will be added to the end of * the generated filename, after a dot. *

* Thus for example a pattern of "%t/java%g.log" with a count of 2 * would typically cause log files to be written on Solaris to * /var/tmp/java0.log and /var/tmp/java1.log whereas on Windows 95 they * would be typically written to C:\TEMP\java0.log and C:\TEMP\java1.log *

* Generation numbers follow the sequence 0, 1, 2, etc. *

* Normally the "%u" unique field is set to 0. However, if the FileHandler * tries to open the filename and finds the file is currently in use by * another process it will increment the unique number field and try * again. This will be repeated until FileHandler finds a file name that * is not currently in use. If there is a conflict and no "%u" field has * been specified, it will be added at the end of the filename after a dot. * (This will be after any automatically added generation number.) *

* Thus if three processes were all trying to log to fred%u.%g.txt then * they might end up using fred0.0.txt, fred1.0.txt, fred2.0.txt as * the first file in their rotating sequences. *

* Note that the use of unique ids to avoid conflicts is only guaranteed * to work reliably when using a local disk file system. * * @version 1.37, 03/23/10 * @since 1.4 */ public class MyFileHandler extends StreamHandler { private MeteredStream meter; private boolean append; private int limit; // zero => no limit. private int count; private String pattern; private String lockFileName; private FileOutputStream lockStream; private File files[]; private static final int MAX_LOCKS = 100; private static java.util.HashMap locks = new java.util.HashMap(); private FileChangeListner _listener = null; interface FileChangeListner { void fileChange(File file, boolean added); } // A metered stream is a subclass of OutputStream that // (a) forwards all its output to a target stream // (b) keeps track of how many bytes have been written private class MeteredStream extends OutputStream { OutputStream out; int written; MeteredStream(OutputStream out, int written) { this.out = out; this.written = written; } public void write(int b) throws IOException { out.write(b); written++; } public void write(byte buff[]) throws IOException { out.write(buff); written += buff.length; } public void write(byte buff[], int off, int len) throws IOException { out.write(buff,off,len); written += len; } public void flush() throws IOException { out.flush(); } public void close() throws IOException { out.close(); } } private void open(File fname, boolean append) throws IOException { int len = 0; if (append) { len = (int)fname.length(); } if (!fname.getParentFile().exists()) fname.getParentFile().mkdirs(); FileOutputStream fout = new FileOutputStream(fname.toString(), append); BufferedOutputStream bout = new BufferedOutputStream(fout); meter = new MeteredStream(bout, len); setOutputStream(meter); } // Private method to configure a FileHandler from LogManager // properties and/or default values as specified in the class // javadoc. 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; } } */ } /** * 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. */ public MyFileHandler() throws IOException, SecurityException { //checkAccess(); configure(); openFiles(); } /** * 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 */ public MyFileHandler(String pattern) throws IOException, SecurityException { if (pattern.length() < 1 ) { throw new IllegalArgumentException(); } //checkAccess(); configure(); this.pattern = pattern; this.limit = 0; this.count = 1; openFiles(); } /** * 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 */ public MyFileHandler(String pattern, boolean append) throws IOException, SecurityException { if (pattern.length() < 1 ) { throw new IllegalArgumentException(); } //checkAccess(); configure(); this.pattern = pattern; this.limit = 0; this.count = 1; this.append = append; openFiles(); } /** * 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 */ public MyFileHandler(String pattern, int limit, int count) throws IOException, SecurityException { if (limit < 0 || count < 1 || pattern.length() < 1) { throw new IllegalArgumentException(); } //checkAccess(); configure(); this.pattern = pattern; this.limit = limit; this.count = count; openFiles(); } /** * 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 * */ public MyFileHandler(String pattern, int limit, int count, boolean append) throws IOException, SecurityException { 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(); } public MyFileHandler(String pattern, int limit, int count, boolean append, PatternFormatter fileFormatter, Level logLevel, String encoding) throws SecurityException, IOException { this(pattern, limit, count, append); if (encoding != null) setEncoding(encoding); setFormatter(fileFormatter); setLevel(logLevel); } // Private method to open the set of output files, based on the // configured instance variables. private void openFiles() throws IOException { 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, count).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, count); } // 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()); } // Generate a filename from a pattern. static File generate(String pattern, int generation, int unique, int count) throws IOException { 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 && generation != 0) { word = word + "." + generation; } if (unique > 0 && !sawu && unique != 0) { word = word + "." + unique; } if (word.length() > 0) { if (file == null) { file = new File(word); } else { file = new File(file, word); } } return file; } // Rotate the set of output files 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(); } else if (_listener != null) _listener.fileChange(f2, true); 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); } /** * Format and publish a LogRecord. * * @param record description of the log event. A null record is * silently ignored and is not published */ public synchronized void publish(LogRecord record) { 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; } }); } } public File currentFile() { return files[0]; } public LinkedList getCurrentFiles() { LinkedList result = new LinkedList(); for (File f : files) { if (f.exists()) result.addLast(f); else break; } return result; } public void setNewFileListner(FileChangeListner listener) { _listener = listener; } /** * Close all the files. * * @exception SecurityException if a security manager exists and if * the caller does not have LoggingPermission("control"). */ public synchronized void close() throws SecurityException { 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 static class InitializationErrorManager extends ErrorManager { Exception lastException; public void error(String msg, Exception ex, int code) { lastException = ex; } } // Private native method to check if we are in a set UID program. private static native boolean isSetUID(); }





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