File	Doc	Category	Size	Date	Package
MemoryHandler.java	API Doc	Java SE 6 API	8409	Tue Jun 10 00:25:58 BST 2008	java.util.logging

MemoryHandler

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

Fields Summary
private static final int	DEFAULT_SIZE
private Level	pushLevel
private int	size
private Handler	target
private LogRecord[]	buffer
int	start
int	count

Constructors Summary
public MemoryHandler() Create a MemoryHandler and configure it based on LogManager configuration properties. sealed = false; configure(); sealed = true; String name = "???"; try { LogManager manager = LogManager.getLogManager(); name = manager.getProperty("java.util.logging.MemoryHandler.target"); Class clz = ClassLoader.getSystemClassLoader().loadClass(name); target = (Handler) clz.newInstance(); } catch (Exception ex) { throw new RuntimeException("MemoryHandler can't load handler \"" + name + "\"" , ex); } init();
public MemoryHandler(Handler target, int size, Level pushLevel) Create a MemoryHandler. The MemoryHandler is configured based on LogManager properties (or their default values) except that the given pushLevel argument and buffer size argument are used. param target the Handler to which to publish output. param size the number of log records to buffer (must be greater than zero) param pushLevel message level to push on throws IllegalArgumentException is size is <= 0 if (target == null || pushLevel == null) { throw new NullPointerException(); } if (size <= 0) { throw new IllegalArgumentException(); } sealed = false; configure(); sealed = true; this.target = target; this.pushLevel = pushLevel; this.size = size; init();

Methods Summary
public void	close() Close the Handler and free all associated resources. This will also close the target Handler. exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). target.close(); setLevel(Level.OFF);
private void	configure() // Private method to configure a ConsoleHandler from LogManager // properties and/or default values as specified in the class // javadoc. LogManager manager = LogManager.getLogManager(); String cname = getClass().getName(); pushLevel = manager.getLevelProperty(cname +".push", Level.SEVERE); size = manager.getIntProperty(cname + ".size", DEFAULT_SIZE); if (size <= 0) { size = DEFAULT_SIZE; } setLevel(manager.getLevelProperty(cname +".level", Level.ALL)); setFilter(manager.getFilterProperty(cname +".filter", null)); setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
public void	flush() Causes a flush on the target Handler. Note that the current contents of the MemoryHandler buffer are not written out. That requires a "push". target.flush();
public synchronized java.util.logging.Level	getPushLevel() Get the pushLevel. return the value of the pushLevel return pushLevel;
private void	init() buffer = new LogRecord[size]; start = 0; count = 0;
public boolean	isLoggable(java.util.logging.LogRecord record) Check if this Handler would actually log a given LogRecord into its internal buffer. This method checks if the LogRecord has an appropriate level and whether it satisfies any Filter. However it does not check whether the LogRecord would result in a "push" of the buffer contents. It will return false if the LogRecord is Null. param record a LogRecord return true if the LogRecord would be logged. return super.isLoggable(record);
public synchronized void	publish(java.util.logging.LogRecord record) Store a LogRecord in an internal buffer. If there is a Filter, its isLoggable method is called to check if the given log record is loggable. If not we return. Otherwise the given record is copied into an internal circular buffer. Then the record's level property is compared with the pushLevel. If the given level is greater than or equal to the pushLevel then push is called to write all buffered records to the target output Handler. param record description of the log event. A null record is silently ignored and is not published if (!isLoggable(record)) { return; } int ix = (start+count)%buffer.length; buffer[ix] = record; if (count < buffer.length) { count++; } else { start++; start %= buffer.length; } if (record.getLevel().intValue() >= pushLevel.intValue()) { push(); }
public synchronized void	push() Push any buffered output to the target Handler. The buffer is then cleared. for (int i = 0; i < count; i++) { int ix = (start+i)%buffer.length; LogRecord record = buffer[ix]; target.publish(record); } // Empty the buffer. start = 0; count = 0;
public void	setPushLevel(java.util.logging.Level newLevel) Set the pushLevel. After a LogRecord is copied into our internal buffer, if its level is greater than or equal to the pushLevel, then push will be called. param newLevel the new value of the pushLevel exception SecurityException if a security manager exists and if the caller does not have LoggingPermission("control"). if (newLevel == null) { throw new NullPointerException(); } LogManager manager = LogManager.getLogManager(); checkAccess(); pushLevel = newLevel;