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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
package java.util.logging;
import java.io.*;
/**
* Stream based logging <tt>Handler</tt>.
* <p>
* This is primarily intended as a base class or support class to
* be used in implementing other logging <tt>Handlers</tt>.
* <p>
* <tt>LogRecords</tt> are published to a given <tt>java.io.OutputStream</tt>.
* <p>
* <b>Configuration:</b>
* By default each <tt>StreamHandler</tt> is initialized using the following
* <tt>LogManager</tt> configuration properties. If properties are not defined
* (or have invalid values) then the specified default values are used.
* <ul>
* <li> java.util.logging.StreamHandler.level
* specifies the default level for the <tt>Handler</tt>
* (defaults to <tt>Level.INFO</tt>).
* <li> java.util.logging.StreamHandler.filter
* specifies the name of a <tt>Filter</tt> class to use
* (defaults to no <tt>Filter</tt>).
* <li> java.util.logging.StreamHandler.formatter
* specifies the name of a <tt>Formatter</tt> class to use
* (defaults to <tt>java.util.logging.SimpleFormatter</tt>).
* <li> java.util.logging.StreamHandler.encoding
* the name of the character set encoding to use (defaults to
* the default platform encoding).
* </ul>
*
* @since 1.4
*/
public class StreamHandler extends Handler {
private LogManager manager = LogManager.getLogManager();
private OutputStream output;
private boolean doneHeader;
private Writer writer;
// Private method to configure a StreamHandler from LogManager
// properties and/or default values as specified in the class
// javadoc.
private void configure() {
LogManager manager = LogManager.getLogManager();
String cname = getClass().getName();
setLevel(manager.getLevelProperty(cname +".level", Level.INFO));
setFilter(manager.getFilterProperty(cname +".filter", null));
setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
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;
}
}
}
/**
* Create a <tt>StreamHandler</tt>, with no current output stream.
*/
public StreamHandler() {
sealed = false;
configure();
sealed = true;
}
/**
* Create a <tt>StreamHandler</tt> with a given <tt>Formatter</tt>
* and output stream.
* <p>
* @param out the target output stream
* @param formatter Formatter to be used to format output
*/
public StreamHandler(OutputStream out, Formatter formatter) {
sealed = false;
configure();
setFormatter(formatter);
setOutputStream(out);
sealed = true;
}
/**
* Change the output stream.
* <P>
* If there is a current output stream then the <tt>Formatter</tt>'s
* tail string is written and the stream is flushed and closed.
* Then the output stream is replaced with the new output stream.
*
* @param out New output stream. May not be null.
* @exception SecurityException if a security manager exists and if
* the caller does not have <tt>LoggingPermission("control")</tt>.
*/
protected synchronized void setOutputStream(OutputStream out) throws SecurityException {
if (out == null) {
throw new NullPointerException();
}
flushAndClose();
output = out;
doneHeader = false;
String encoding = getEncoding();
if (encoding == null) {
writer = new OutputStreamWriter(output);
} else {
try {
writer = new OutputStreamWriter(output, encoding);
} catch (UnsupportedEncodingException ex) {
// This shouldn't happen. The setEncoding method
// should have validated that the encoding is OK.
throw new Error("Unexpected exception " + ex);
}
}
}
/**
* Set (or change) the character encoding used by this <tt>Handler</tt>.
* <p>
* The encoding should be set before any <tt>LogRecords</tt> are written
* to the <tt>Handler</tt>.
*
* @param encoding The name of a supported character encoding.
* May be null, to indicate the default platform encoding.
* @exception SecurityException if a security manager exists and if
* the caller does not have <tt>LoggingPermission("control")</tt>.
* @exception UnsupportedEncodingException if the named encoding is
* not supported.
*/
public void setEncoding(String encoding)
throws SecurityException, java.io.UnsupportedEncodingException {
super.setEncoding(encoding);
if (output == null) {
return;
}
// Replace the current writer with a writer for the new encoding.
flush();
if (encoding == null) {
writer = new OutputStreamWriter(output);
} else {
writer = new OutputStreamWriter(output, encoding);
}
}
/**
* Format and publish a <tt>LogRecord</tt>.
* <p>
* The <tt>StreamHandler</tt> first checks if there is an <tt>OutputStream</tt>
* and if the given <tt>LogRecord</tt> has at least the required log level.
* If not it silently returns. If so, it calls any associated
* <tt>Filter</tt> to check if the record should be published. If so,
* it calls its <tt>Formatter</tt> to format the record and then writes
* the result to the current output stream.
* <p>
* If this is the first <tt>LogRecord</tt> to be written to a given
* <tt>OutputStream</tt>, the <tt>Formatter</tt>'s "head" string is
* written to the stream before the <tt>LogRecord</tt> is written.
*
* @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;
}
String msg;
try {
msg = getFormatter().format(record);
} catch (Exception ex) {
// We don't want to throw an exception here, but we
// report the exception to any registered ErrorManager.
reportError(null, ex, ErrorManager.FORMAT_FAILURE);
return;
}
try {
if (!doneHeader) {
writer.write(getFormatter().getHead(this));
doneHeader = true;
}
writer.write(msg);
} catch (Exception ex) {
// We don't want to throw an exception here, but we
// report the exception to any registered ErrorManager.
reportError(null, ex, ErrorManager.WRITE_FAILURE);
}
}
/**
* Check if this <tt>Handler</tt> would actually log a given <tt>LogRecord</tt>.
* <p>
* This method checks if the <tt>LogRecord</tt> has an appropriate level and
* whether it satisfies any <tt>Filter</tt>. It will also return false if
* no output stream has been assigned yet or the LogRecord is Null.
* <p>
* @param record a <tt>LogRecord</tt>
* @return true if the <tt>LogRecord</tt> would be logged.
*
*/
public boolean isLoggable(LogRecord record) {
if (writer == null || record == null) {
return false;
}
return super.isLoggable(record);
}
/**
* Flush any buffered messages.
*/
public synchronized void flush() {
if (writer != null) {
try {
writer.flush();
} catch (Exception ex) {
// We don't want to throw an exception here, but we
// report the exception to any registered ErrorManager.
reportError(null, ex, ErrorManager.FLUSH_FAILURE);
}
}
}
private synchronized void flushAndClose() throws SecurityException {
checkPermission();
if (writer != null) {
try {
if (!doneHeader) {
writer.write(getFormatter().getHead(this));
doneHeader = true;
}
writer.write(getFormatter().getTail(this));
writer.flush();
writer.close();
} catch (Exception ex) {
// We don't want to throw an exception here, but we
// report the exception to any registered ErrorManager.
reportError(null, ex, ErrorManager.CLOSE_FAILURE);
}
writer = null;
output = null;
}
}
/**
* Close the current output stream.
* <p>
* The <tt>Formatter</tt>'s "tail" string is written to the stream before it
* is closed. In addition, if the <tt>Formatter</tt>'s "head" string has not
* yet been written to the stream, it will be written before the
* "tail" string.
*
* @exception SecurityException if a security manager exists and if
* the caller does not have LoggingPermission("control").
*/
public synchronized void close() throws SecurityException {
flushAndClose();
}
}