StreamHandler (Java Platform SE 8 ) (original) (raw)

• java.lang.Object

• • java.util.logging.Handler
  • • java.util.logging.StreamHandler

• Direct Known Subclasses:
  ConsoleHandler, FileHandler, SocketHandler

public class StreamHandler
extends Handler
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 followingLogManager configuration properties where 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.

• .level specifies the default level for the Handler (defaults to Level.INFO).

• .filter specifies the name of a Filter class to use (defaults to no Filter).

• .formatter specifies the name of a Formatter class to use (defaults to java.util.logging.SimpleFormatter).

• .encoding the name of the character set encoding to use (defaults to the default platform encoding).
  For example, the properties for StreamHandler would be:

• java.util.logging.StreamHandler.level=INFO

• java.util.logging.StreamHandler.formatter=java.util.logging.SimpleFormatter
  For a custom handler, e.g. com.foo.MyHandler, the properties would be:

• com.foo.MyHandler.level=INFO

• com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter
  Since:
  1.4

• • Constructor Summary

  Constructors

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

  • Method Summary

  All Methods Instance Methods Concrete Methods

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

     * ### Methods inherited from class java.util.logging.[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")  
     `[getEncoding](../../../java/util/logging/Handler.html#getEncoding--), [getErrorManager](../../../java/util/logging/Handler.html#getErrorManager--), [getFilter](../../../java/util/logging/Handler.html#getFilter--), [getFormatter](../../../java/util/logging/Handler.html#getFormatter--), [getLevel](../../../java/util/logging/Handler.html#getLevel--), [reportError](../../../java/util/logging/Handler.html#reportError-java.lang.String-java.lang.Exception-int-), [setErrorManager](../../../java/util/logging/Handler.html#setErrorManager-java.util.logging.ErrorManager-), [setFilter](../../../java/util/logging/Handler.html#setFilter-java.util.logging.Filter-), [setFormatter](../../../java/util/logging/Handler.html#setFormatter-java.util.logging.Formatter-), [setLevel](../../../java/util/logging/Handler.html#setLevel-java.util.logging.Level-)`  
     * ### Methods inherited from class java.lang.[Object](../../../java/lang/Object.html "class in java.lang")  
     `[clone](../../../java/lang/Object.html#clone--), [equals](../../../java/lang/Object.html#equals-java.lang.Object-), [finalize](../../../java/lang/Object.html#finalize--), [getClass](../../../java/lang/Object.html#getClass--), [hashCode](../../../java/lang/Object.html#hashCode--), [notify](../../../java/lang/Object.html#notify--), [notifyAll](../../../java/lang/Object.html#notifyAll--), [toString](../../../java/lang/Object.html#toString--), [wait](../../../java/lang/Object.html#wait--), [wait](../../../java/lang/Object.html#wait-long-), [wait](../../../java/lang/Object.html#wait-long-int-)`

• • Constructor Detail

     * #### StreamHandler  
     public StreamHandler()  
     Create a  
     StreamHandler  
     , with no current output stream.  
     * #### StreamHandler  
     public StreamHandler([OutputStream](../../../java/io/OutputStream.html "class in java.io") out,  
                          [Formatter](../../../java/util/logging/Formatter.html "class in java.util.logging") 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  

  • Method Detail

    * #### setOutputStream  
    protected void setOutputStream([OutputStream](../../../java/io/OutputStream.html "class in java.io") out)  
                            throws [SecurityException](../../../java/lang/SecurityException.html "class in java.lang")  
    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](../../../java/lang/SecurityException.html "class in java.lang")` \- if a security manager exists and if the caller does not have LoggingPermission("control").  
    * #### setEncoding  
    public void setEncoding([String](../../../java/lang/String.html "class in java.lang") encoding)  
                     throws [SecurityException](../../../java/lang/SecurityException.html "class in java.lang"),  
                            [UnsupportedEncodingException](../../../java/io/UnsupportedEncodingException.html "class in java.io")  
    Set (or change) the character encoding used by this  
    Handler  
    .  
     The encoding should be set before any LogRecords are written to the Handler.  
    Overrides:  
    `[setEncoding](../../../java/util/logging/Handler.html#setEncoding-java.lang.String-)` in class `[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")`  
    Parameters:  
    `encoding` \- The name of a supported character encoding. May be null, to indicate the default platform encoding.  
    Throws:  
    `[SecurityException](../../../java/lang/SecurityException.html "class in java.lang")` \- if a security manager exists and if the caller does not have LoggingPermission("control").  
    `[UnsupportedEncodingException](../../../java/io/UnsupportedEncodingException.html "class in java.io")` \- if the named encoding is not supported.  
    * #### publish  
    public void publish([LogRecord](../../../java/util/logging/LogRecord.html "class in java.util.logging") 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 associatedFilter 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 givenOutputStream, the Formatter's "head" string is written to the stream before the LogRecord is written.  
    Specified by:  
    `[publish](../../../java/util/logging/Handler.html#publish-java.util.logging.LogRecord-)` in class `[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")`  
    Parameters:  
    `record` \- description of the log event. A null record is silently ignored and is not published  
    * #### isLoggable  
    public boolean isLoggable([LogRecord](../../../java/util/logging/LogRecord.html "class in java.util.logging") 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.  
    Overrides:  
    `[isLoggable](../../../java/util/logging/Handler.html#isLoggable-java.util.logging.LogRecord-)` in class `[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")`  
    Parameters:  
    `record` \- a LogRecord  
    Returns:  
    true if the LogRecord would be logged.  
    * #### flush  
    public void flush()  
    Flush any buffered messages.  
    Specified by:  
    `[flush](../../../java/util/logging/Handler.html#flush--)` in class `[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")`  
    * #### close  
    public void close()  
               throws [SecurityException](../../../java/lang/SecurityException.html "class in java.lang")  
    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.  
    Specified by:  
    `[close](../../../java/util/logging/Handler.html#close--)` in class `[Handler](../../../java/util/logging/Handler.html "class in java.util.logging")`  
    Throws:  
    `[SecurityException](../../../java/lang/SecurityException.html "class in java.lang")` \- if a security manager exists and if the caller does not have LoggingPermission("control").

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