StreamHandler

public class StreamHandler extends Handler
Known Direct Subclasses

Stream based logging Handler.

This is primarily intended as a base class or support class to be used in implementing other logging Handlers.

LogRecords are published to a given java.io.OutputStream.

Configuration: By default each StreamHandler 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.StreamHandler.level specifies the default level for the Handler (defaults to Level.INFO).
  • java.util.logging.StreamHandler.filter specifies the name of a Filter class to use (defaults to no Filter).
  • java.util.logging.StreamHandler.formatter specifies the name of a Formatter class to use (defaults to java.util.logging.SimpleFormatter).
  • java.util.logging.StreamHandler.encoding the name of the character set encoding to use (defaults to the default platform encoding).

Public Constructor Summary

StreamHandler()
Create a StreamHandler, with no current output stream.
StreamHandler(OutputStream out, Formatter formatter)
Create a StreamHandler with a given Formatter and output stream.

Public Method Summary

synchronized void
close()
Close the current output stream.
synchronized void
flush()
Flush any buffered messages.
boolean
isLoggable(LogRecord record)
Check if this Handler would actually log a given LogRecord.
synchronized void
publish(LogRecord record)
Format and publish a LogRecord.
void
setEncoding(String encoding)
Set (or change) the character encoding used by this Handler.

Protected Method Summary

synchronized void
setOutputStream(OutputStream out)
Change the output stream.

Inherited Method Summary

Public Constructors

public StreamHandler ()

Create a StreamHandler, with no current output stream.

public StreamHandler (OutputStream out, Formatter formatter)

Create a StreamHandler with a given Formatter and output stream.

Parameters
out the target output stream
formatter Formatter to be used to format output

Public Methods

public synchronized void close ()

Close the current output stream.

The Formatter's "tail" string is written to the stream before it is closed. In addition, if the Formatter's "head" string has not yet been written to the stream, it will be written before the "tail" string.

Throws
SecurityException if a security manager exists and if the caller does not have LoggingPermission("control").

public synchronized void flush ()

Flush any buffered messages.

public boolean isLoggable (LogRecord record)

Check if this Handler would actually log a given LogRecord.

This method checks if the LogRecord has an appropriate level and whether it satisfies any Filter. It will also return false if no output stream has been assigned yet or the LogRecord is null.

Parameters
record a LogRecord
Returns
  • true if the LogRecord would be logged.

public synchronized void publish (LogRecord record)

Format and publish a LogRecord.

The StreamHandler first checks if there is an OutputStream and if the given LogRecord has at least the required log level. If not it silently returns. If so, it calls any associated Filter to check if the record should be published. If so, it calls its Formatter to format the record and then writes the result to the current output stream.

If this is the first LogRecord to be written to a given OutputStream, the Formatter's "head" string is written to the stream before the LogRecord is written.

Parameters
record description of the log event. A null record is silently ignored and is not published

public void setEncoding (String encoding)

Set (or change) the character encoding used by this Handler.

The encoding should be set before any LogRecords are written to the Handler.

Parameters
encoding The name of a supported character encoding. May be null, to indicate the default platform encoding.
Throws
SecurityException if a security manager exists and if the caller does not have LoggingPermission("control").
UnsupportedEncodingException if the named encoding is not supported.

Protected Methods

protected synchronized void setOutputStream (OutputStream out)

Change the output stream.

If there is a current output stream then the Formatter's tail string is written and the stream is flushed and closed. Then the output stream is replaced with the new output stream.

Parameters
out New output stream. May not be null.
Throws
SecurityException if a security manager exists and if the caller does not have LoggingPermission("control").