JDK 17 java.logging.jmod - Logging Module
JDK 17 java.logging.jmod is the JMOD file for JDK 17 Logging module.
JDK 17 Logging module compiled class files are stored in \fyicenter\jdk-17.0.5\jmods\java.logging.jmod.
JDK 17 Logging module compiled class files are also linked and stored in the \fyicenter\jdk-17.0.5\lib\modules JImage file.
JDK 17 Logging module source code files are stored in \fyicenter\jdk-17.0.5\lib\src.zip\java.logging.
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⏎ java/util/logging/FileHandler.java
/*
* Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.util.logging;
import static java.nio.file.StandardOpenOption.APPEND;
import static java.nio.file.StandardOpenOption.CREATE_NEW;
import static java.nio.file.StandardOpenOption.WRITE;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.channels.FileChannel;
import java.nio.channels.OverlappingFileLockException;
import java.nio.file.AccessDeniedException;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashSet;
import java.util.Set;
/**
* Simple file logging {@code Handler}.
* <p>
* The {@code FileHandler} can either write to a specified file,
* or it can write to a rotating set of files.
* <p>
* 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.
* <p>
* By default buffering is enabled in the IO libraries but each log
* record is flushed out when it is complete.
* <p>
* By default the {@code XMLFormatter} class is used for formatting.
* <p>
* <b>Configuration:</b>
* By default each {@code FileHandler} is initialized using the following
* {@code LogManager} configuration properties where {@code <handler-name>}
* refers to the fully-qualified class name of the handler.
* If properties are not defined
* (or have invalid values) then the specified default values are used.
* <ul>
* <li> <handler-name>.level
* specifies the default level for the {@code Handler}
* (defaults to {@code Level.ALL}). </li>
* <li> <handler-name>.filter
* specifies the name of a {@code Filter} class to use
* (defaults to no {@code Filter}). </li>
* <li> <handler-name>.formatter
* specifies the name of a {@code Formatter} class to use
* (defaults to {@code java.util.logging.XMLFormatter}) </li>
* <li> <handler-name>.encoding
* the name of the character set encoding to use (defaults to
* the default platform encoding). </li>
* <li> <handler-name>.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). </li>
* <li> <handler-name>.count
* specifies how many output files to cycle through (defaults to 1). </li>
* <li> <handler-name>.pattern
* specifies a pattern for generating the output file name. See
* below for details. (Defaults to "%h/java%u.log"). </li>
* <li> <handler-name>.append
* specifies whether the FileHandler should append onto
* any existing files (defaults to false). </li>
* <li> <handler-name>.maxLocks
* specifies the maximum number of concurrent locks held by
* FileHandler (defaults to 100). </li>
* </ul>
* <p>
* For example, the properties for {@code FileHandler} would be:
* <ul>
* <li> java.util.logging.FileHandler.level=INFO </li>
* <li> java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter </li>
* </ul>
* <p>
* For a custom handler, e.g. com.foo.MyHandler, the properties would be:
* <ul>
* <li> com.foo.MyHandler.level=INFO </li>
* <li> com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter </li>
* </ul>
* <p>
* A pattern consists of a string that includes the following special
* components that will be replaced at runtime:
* <ul>
* <li> "/" the local pathname separator </li>
* <li> "%t" the system temporary directory </li>
* <li> "%h" the value of the "user.home" system property </li>
* <li> "%g" the generation number to distinguish rotated logs </li>
* <li> "%u" a unique number to resolve conflicts </li>
* <li> "%%" translates to a single percent sign "%" </li>
* </ul>
* 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.
* <p>
* 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
* <p>
* Generation numbers follow the sequence 0, 1, 2, etc.
* <p>
* Normally the "%u" unique field is set to 0. However, if the {@code 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 {@code 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.)
* <p>
* 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.
* <p>
* Note that the use of unique ids to avoid conflicts is only guaranteed
* to work reliably when using a local disk file system.
*
* @since 1.4
*/
public class FileHandler extends StreamHandler {
private MeteredStream meter;
private boolean append;
private long limit; // zero => no limit.
private int count;
private String pattern;
private String lockFileName;
private FileChannel lockFileChannel;
private File files[];
private static final int MAX_LOCKS = 100;
private int maxLocks = MAX_LOCKS;
private static final Set<String> locks = new HashSet<>();
/**
* 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 static final class MeteredStream extends OutputStream {
final OutputStream out;
long written;
MeteredStream(OutputStream out, long written) {
this.out = out;
this.written = written;
}
@Override
public void write(int b) throws IOException {
out.write(b);
written++;
}
@Override
public void write(byte buff[]) throws IOException {
out.write(buff);
written += buff.length;
}
@Override
public void write(byte buff[], int off, int len) throws IOException {
out.write(buff,off,len);
written += len;
}
@Override
public void flush() throws IOException {
out.flush();
}
@Override
public void close() throws IOException {
out.close();
}
}
private void open(File fname, boolean append) throws IOException {
long len = 0;
if (append) {
len = fname.length();
}
FileOutputStream fout = new FileOutputStream(fname.toString(), append);
BufferedOutputStream bout = new BufferedOutputStream(fout);
meter = new MeteredStream(bout, len);
setOutputStream(meter);
}
/**
* 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.getLongProperty(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()));
// Initialize maxLocks from the logging.properties file.
// If invalid/no property is provided 100 will be used as a default value.
maxLocks = manager.getIntProperty(cname + ".maxLocks", MAX_LOCKS);
if(maxLocks <= 0) {
maxLocks = MAX_LOCKS;
}
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 {@code FileHandler}. This will be configured
* entirely from {@code LogManager} properties (or their default values).
*
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control"))}.
* @throws NullPointerException if pattern property is an empty String.
*/
public FileHandler() throws IOException, SecurityException {
checkPermission();
configure();
// pattern will have been set by configure. check that it's not
// empty.
if (pattern.isEmpty()) {
throw new NullPointerException();
}
openFiles();
}
/**
* Initialize a {@code FileHandler} to write to the given filename.
* <p>
* The {@code FileHandler} is configured based on {@code 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.
* <p>
* 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
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
* @throws IllegalArgumentException if pattern is an empty string
*/
public FileHandler(String pattern) throws IOException, SecurityException {
if (pattern.length() < 1 ) {
throw new IllegalArgumentException();
}
checkPermission();
configure();
this.pattern = pattern;
this.limit = 0;
this.count = 1;
openFiles();
}
/**
* Initialize a {@code FileHandler} to write to the given filename,
* with optional append.
* <p>
* The {@code FileHandler} is configured based on {@code 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 {@code append} argument.
* <p>
* 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
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
* @throws IllegalArgumentException if pattern is an empty string
*/
public FileHandler(String pattern, boolean append) throws IOException,
SecurityException {
if (pattern.length() < 1 ) {
throw new IllegalArgumentException();
}
checkPermission();
configure();
this.pattern = pattern;
this.limit = 0;
this.count = 1;
this.append = append;
openFiles();
}
/**
* Initialize a {@code 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.
* <p>
* The {@code FileHandler} is configured based on {@code 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.
* <p>
* 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
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
* @throws IllegalArgumentException if {@code limit < 0}, or {@code count < 1}.
* @throws IllegalArgumentException if pattern is an empty string
*/
public FileHandler(String pattern, int limit, int count)
throws IOException, SecurityException {
if (limit < 0 || count < 1 || pattern.length() < 1) {
throw new IllegalArgumentException();
}
checkPermission();
configure();
this.pattern = pattern;
this.limit = limit;
this.count = count;
openFiles();
}
/**
* Initialize a {@code 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.
* <p>
* The {@code FileHandler} is configured based on {@code 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
* {@code append} argument.
* <p>
* 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
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
* @throws IllegalArgumentException if {@code limit < 0}, or {@code count < 1}.
* @throws IllegalArgumentException if pattern is an empty string
*
*/
public FileHandler(String pattern, int limit, int count, boolean append)
throws IOException, SecurityException {
this(pattern, (long)limit, count, append);
}
/**
* Initialize a {@code 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.
* <p>
* The {@code FileHandler} is configured based on {@code 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
* {@code append} argument.
* <p>
* 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
* @throws IOException if there are IO problems opening the files.
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
* @throws IllegalArgumentException if {@code limit < 0}, or {@code count < 1}.
* @throws IllegalArgumentException if pattern is an empty string
*
* @since 9
*
*/
public FileHandler(String pattern, long limit, int count, boolean append)
throws IOException {
if (limit < 0 || count < 1 || pattern.length() < 1) {
throw new IllegalArgumentException();
}
checkPermission();
configure();
this.pattern = pattern;
this.limit = limit;
this.count = count;
this.append = append;
openFiles();
}
private boolean isParentWritable(Path path) {
Path parent = path.getParent();
if (parent == null) {
parent = path.toAbsolutePath().getParent();
}
return parent != null && Files.isWritable(parent);
}
/**
* Open the set of output files, based on the configured
* instance variables.
*/
private void openFiles() throws IOException {
LogManager manager = LogManager.getLogManager();
manager.checkPermission();
if (count < 1) {
throw new IllegalArgumentException("file count = " + count);
}
if (limit < 0) {
limit = 0;
}
// All constructors check that pattern is neither null nor empty.
assert pattern != null : "pattern should not be null";
assert !pattern.isEmpty() : "pattern should not be empty";
// 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 > maxLocks) {
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.contains(lockFileName)) {
// We already own this lock, for a different FileHandler
// object. Try again.
continue;
}
final Path lockFilePath = Paths.get(lockFileName);
FileChannel channel = null;
int retries = -1;
boolean fileCreated = false;
while (channel == null && retries++ < 1) {
try {
channel = FileChannel.open(lockFilePath,
CREATE_NEW, WRITE);
fileCreated = true;
} catch (AccessDeniedException ade) {
// This can be either a temporary, or a more permanent issue.
// The lock file might be still pending deletion from a previous run
// (temporary), or the parent directory might not be accessible,
// not writable, etc..
// If we can write to the current directory, and this is a regular file,
// let's try again.
if (Files.isRegularFile(lockFilePath, LinkOption.NOFOLLOW_LINKS)
&& isParentWritable(lockFilePath)) {
// Try again. If it doesn't work, then this will
// eventually ensure that we increment "unique" and
// use another file name.
continue;
} else {
throw ade; // no need to retry
}
} catch (FileAlreadyExistsException ix) {
// This may be a zombie file left over by a previous
// execution. Reuse it - but only if we can actually
// write to its directory.
// Note that this is a situation that may happen,
// but not too frequently.
if (Files.isRegularFile(lockFilePath, LinkOption.NOFOLLOW_LINKS)
&& isParentWritable(lockFilePath)) {
try {
channel = FileChannel.open(lockFilePath,
WRITE, APPEND);
} catch (NoSuchFileException x) {
// Race condition - retry once, and if that
// fails again just try the next name in
// the sequence.
continue;
} catch(IOException x) {
// the file may not be writable for us.
// try the next name in the sequence
break;
}
} else {
// at this point channel should still be null.
// break and try the next name in the sequence.
break;
}
}
}
if (channel == null) continue; // try the next name;
lockFileChannel = channel;
boolean available;
try {
available = lockFileChannel.tryLock() != null;
// We got the lock OK.
// At this point we could call File.deleteOnExit().
// However, this could have undesirable side effects
// as indicated by JDK-4872014. So we will instead
// rely on the fact that close() will remove the lock
// file and that whoever is creating FileHandlers should
// be responsible for closing them.
} 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, but only if we did
// create the file...
available = fileCreated;
} catch (OverlappingFileLockException x) {
// someone already locked this file in this VM, through
// some other channel - that is - using something else
// than new FileHandler(...);
// continue searching for an available lock.
available = false;
}
if (available) {
// We got the lock. Remember it.
locks.add(lockFileName);
break;
}
// We failed to get the lock. Try next file.
lockFileChannel.close();
}
}
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());
}
/**
* Generate a file based on a user-supplied pattern, generation number,
* and an integer uniqueness suffix
* @param pattern the pattern for naming the output file
* @param generation the generation number to distinguish rotated logs
* @param unique a unique number to resolve conflicts
* @return the generated File
* @throws IOException
*/
private File generate(String pattern, int generation, int unique)
throws IOException
{
return generate(pattern, count, generation, unique);
}
// The static method here is provided for whitebox testing of the algorithm.
static File generate(String pat, int count, int generation, int unique)
throws IOException
{
Path path = Paths.get(pat);
Path result = null;
boolean sawg = false;
boolean sawu = false;
StringBuilder word = new StringBuilder();
Path prev = null;
for (Path elem : path) {
if (prev != null) {
prev = prev.resolveSibling(word.toString());
result = result == null ? prev : result.resolve(prev);
}
String pattern = elem.toString();
int ix = 0;
word.setLength(0);
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 (ch2 == 't') {
String tmpDir = System.getProperty("java.io.tmpdir");
if (tmpDir == null) {
tmpDir = System.getProperty("user.home");
}
result = Paths.get(tmpDir);
ix++;
word.setLength(0);
continue;
} else if (ch2 == 'h') {
result = Paths.get(System.getProperty("user.home"));
if (jdk.internal.misc.VM.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.setLength(0);
continue;
} else if (ch2 == 'g') {
word = word.append(generation);
sawg = true;
ix++;
continue;
} else if (ch2 == 'u') {
word = word.append(unique);
sawu = true;
ix++;
continue;
} else if (ch2 == '%') {
word = word.append('%');
ix++;
continue;
}
}
word = word.append(ch);
}
prev = elem;
}
if (count > 1 && !sawg) {
word = word.append('.').append(generation);
}
if (unique > 0 && !sawu) {
word = word.append('.').append(unique);
}
if (word.length() > 0) {
String n = word.toString();
Path p = prev == null ? Paths.get(n) : prev.resolveSibling(n);
result = result == null ? p : result.resolve(p);
} else if (result == null) {
result = Paths.get("");
}
if (path.getRoot() == null) {
return result.toFile();
} else {
return path.getRoot().resolve(result).toFile();
}
}
/**
* 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();
}
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 {@code LogRecord}.
*
* @param record description of the log event. A null record is
* silently ignored and is not published
*/
@SuppressWarnings("removal")
@Override
public synchronized void publish(LogRecord record) {
if (!isLoggable(record)) {
return;
}
super.publish(record);
flush();
if (limit > 0 && (meter.written >= limit || meter.written < 0)) {
// 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<Object>() {
@Override
public Object run() {
rotate();
return null;
}
});
}
}
/**
* Close all the files.
*
* @throws SecurityException if a security manager exists and if
* the caller does not have {@code LoggingPermission("control")}.
*/
@Override
public synchronized void close() throws SecurityException {
super.close();
// Unlock any lock file.
if (lockFileName == null) {
return;
}
try {
// Close the lock file channel (which also will free any locks)
lockFileChannel.close();
} catch (Exception ex) {
// Problems closing the stream. Punt.
}
synchronized(locks) {
locks.remove(lockFileName);
}
new File(lockFileName).delete();
lockFileName = null;
lockFileChannel = null;
}
private static class InitializationErrorManager extends ErrorManager {
Exception lastException;
@Override
public void error(String msg, Exception ex, int code) {
lastException = ex;
}
}
}
⏎ java/util/logging/FileHandler.java
Or download all of them as a single archive file:
File name: java.logging-17.0.5-src.zip File size: 106791 bytes Release date: 2022-09-13 Download
⇒ JDK 17 java.management.jmod - Management Module
2023-09-23, 2013👍, 0💬
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