author | mchung |
Mon, 26 Nov 2012 22:49:06 -0800 | |
changeset 16098 | 9001e536ab4e |
parent 14216 | 23714b376286 |
child 14333 | 65fe875afb41 |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.util.logging; |
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/** |
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* <tt>Handler</tt> that buffers requests in a circular buffer in memory. |
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* <p> |
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* Normally this <tt>Handler</tt> simply stores incoming <tt>LogRecords</tt> |
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* into its memory buffer and discards earlier records. This buffering |
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* is very cheap and avoids formatting costs. On certain trigger |
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* conditions, the <tt>MemoryHandler</tt> will push out its current buffer |
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* contents to a target <tt>Handler</tt>, which will typically publish |
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* them to the outside world. |
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* <p> |
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* There are three main models for triggering a push of the buffer: |
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* <ul> |
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* <li> |
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* An incoming <tt>LogRecord</tt> has a type that is greater than |
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* a pre-defined level, the <tt>pushLevel</tt>. |
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* <li> |
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* An external class calls the <tt>push</tt> method explicitly. |
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* <li> |
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* A subclass overrides the <tt>log</tt> method and scans each incoming |
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* <tt>LogRecord</tt> and calls <tt>push</tt> if a record matches some |
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* desired criteria. |
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* </ul> |
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* <p> |
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* <b>Configuration:</b> |
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* By default each <tt>MemoryHandler</tt> is initialized using the following |
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* LogManager configuration properties. If properties are not defined |
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* (or have invalid values) then the specified default values are used. |
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* If no default value is defined then a RuntimeException is thrown. |
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* <ul> |
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* <li> java.util.logging.MemoryHandler.level |
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* specifies the level for the <tt>Handler</tt> |
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* (defaults to <tt>Level.ALL</tt>). |
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* <li> java.util.logging.MemoryHandler.filter |
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* specifies the name of a <tt>Filter</tt> class to use |
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* (defaults to no <tt>Filter</tt>). |
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* <li> java.util.logging.MemoryHandler.size |
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* defines the buffer size (defaults to 1000). |
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* <li> java.util.logging.MemoryHandler.push |
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* defines the <tt>pushLevel</tt> (defaults to <tt>level.SEVERE</tt>). |
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* <li> java.util.logging.MemoryHandler.target |
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* specifies the name of the target <tt>Handler </tt> class. |
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* (no default). |
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* </ul> |
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* |
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* @since 1.4 |
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*/ |
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public class MemoryHandler extends Handler { |
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private final static int DEFAULT_SIZE = 1000; |
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private Level pushLevel; |
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private int size; |
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private Handler target; |
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private LogRecord buffer[]; |
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int start, count; |
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// Private method to configure a ConsoleHandler from LogManager |
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// properties and/or default values as specified in the class |
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// javadoc. |
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private void configure() { |
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LogManager manager = LogManager.getLogManager(); |
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String cname = getClass().getName(); |
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pushLevel = manager.getLevelProperty(cname +".push", Level.SEVERE); |
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size = manager.getIntProperty(cname + ".size", DEFAULT_SIZE); |
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if (size <= 0) { |
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size = DEFAULT_SIZE; |
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} |
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setLevel(manager.getLevelProperty(cname +".level", Level.ALL)); |
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setFilter(manager.getFilterProperty(cname +".filter", null)); |
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setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter())); |
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} |
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/** |
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* Create a <tt>MemoryHandler</tt> and configure it based on |
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* <tt>LogManager</tt> configuration properties. |
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*/ |
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public MemoryHandler() { |
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sealed = false; |
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configure(); |
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sealed = true; |
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String name = "???"; |
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try { |
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LogManager manager = LogManager.getLogManager(); |
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name = manager.getProperty("java.util.logging.MemoryHandler.target"); |
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Class clz = ClassLoader.getSystemClassLoader().loadClass(name); |
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target = (Handler) clz.newInstance(); |
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} catch (Exception ex) { |
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throw new RuntimeException("MemoryHandler can't load handler \"" + name + "\"" , ex); |
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} |
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init(); |
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} |
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// Initialize. Size is a count of LogRecords. |
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private void init() { |
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buffer = new LogRecord[size]; |
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start = 0; |
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count = 0; |
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} |
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/** |
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* Create a <tt>MemoryHandler</tt>. |
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* <p> |
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* The <tt>MemoryHandler</tt> is configured based on <tt>LogManager</tt> |
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* properties (or their default values) except that the given <tt>pushLevel</tt> |
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* argument and buffer size argument are used. |
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* |
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* @param target the Handler to which to publish output. |
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* @param size the number of log records to buffer (must be greater than zero) |
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* @param pushLevel message level to push on |
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* |
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* @throws IllegalArgumentException if size is <= 0 |
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*/ |
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public MemoryHandler(Handler target, int size, Level pushLevel) { |
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if (target == null || pushLevel == null) { |
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throw new NullPointerException(); |
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} |
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if (size <= 0) { |
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throw new IllegalArgumentException(); |
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} |
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sealed = false; |
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configure(); |
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sealed = true; |
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this.target = target; |
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this.pushLevel = pushLevel; |
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this.size = size; |
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init(); |
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} |
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/** |
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* Store a <tt>LogRecord</tt> in an internal buffer. |
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* <p> |
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* If there is a <tt>Filter</tt>, its <tt>isLoggable</tt> |
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* method is called to check if the given log record is loggable. |
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* If not we return. Otherwise the given record is copied into |
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* an internal circular buffer. Then the record's level property is |
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* compared with the <tt>pushLevel</tt>. If the given level is |
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* greater than or equal to the <tt>pushLevel</tt> then <tt>push</tt> |
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* is called to write all buffered records to the target output |
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* <tt>Handler</tt>. |
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* |
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* @param record description of the log event. A null record is |
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* silently ignored and is not published |
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*/ |
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public synchronized void publish(LogRecord record) { |
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if (!isLoggable(record)) { |
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return; |
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} |
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int ix = (start+count)%buffer.length; |
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buffer[ix] = record; |
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if (count < buffer.length) { |
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count++; |
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} else { |
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start++; |
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start %= buffer.length; |
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} |
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if (record.getLevel().intValue() >= pushLevel.intValue()) { |
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push(); |
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} |
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} |
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/** |
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* Push any buffered output to the target <tt>Handler</tt>. |
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* <p> |
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* The buffer is then cleared. |
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*/ |
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public synchronized void push() { |
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for (int i = 0; i < count; i++) { |
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int ix = (start+i)%buffer.length; |
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LogRecord record = buffer[ix]; |
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target.publish(record); |
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} |
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// Empty the buffer. |
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start = 0; |
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count = 0; |
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} |
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/** |
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* Causes a flush on the target <tt>Handler</tt>. |
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* <p> |
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* Note that the current contents of the <tt>MemoryHandler</tt> |
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* buffer are <b>not</b> written out. That requires a "push". |
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*/ |
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public void flush() { |
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target.flush(); |
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} |
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/** |
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* Close the <tt>Handler</tt> and free all associated resources. |
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* This will also close the target <tt>Handler</tt>. |
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* |
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* @exception SecurityException if a security manager exists and if |
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* the caller does not have <tt>LoggingPermission("control")</tt>. |
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*/ |
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public void close() throws SecurityException { |
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target.close(); |
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setLevel(Level.OFF); |
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} |
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/** |
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* Set the <tt>pushLevel</tt>. After a <tt>LogRecord</tt> is copied |
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* into our internal buffer, if its level is greater than or equal to |
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* the <tt>pushLevel</tt>, then <tt>push</tt> will be called. |
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* |
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* @param newLevel the new value of the <tt>pushLevel</tt> |
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* @exception SecurityException if a security manager exists and if |
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* the caller does not have <tt>LoggingPermission("control")</tt>. |
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*/ |
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public void setPushLevel(Level newLevel) throws SecurityException { |
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if (newLevel == null) { |
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throw new NullPointerException(); |
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} |
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LogManager manager = LogManager.getLogManager(); |
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23714b376286
7169884: LogManager checks do not work correctly for sub-types
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checkPermission(); |
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pushLevel = newLevel; |
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} |
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/** |
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* Get the <tt>pushLevel</tt>. |
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* |
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* @return the value of the <tt>pushLevel</tt> |
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*/ |
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public synchronized Level getPushLevel() { |
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return pushLevel; |
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} |
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/** |
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* Check if this <tt>Handler</tt> would actually log a given |
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* <tt>LogRecord</tt> into its internal buffer. |
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* <p> |
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* This method checks if the <tt>LogRecord</tt> has an appropriate level and |
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* whether it satisfies any <tt>Filter</tt>. However it does <b>not</b> |
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* check whether the <tt>LogRecord</tt> would result in a "push" of the |
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* buffer contents. It will return false if the <tt>LogRecord</tt> is null. |
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* <p> |
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* @param record a <tt>LogRecord</tt> |
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* @return true if the <tt>LogRecord</tt> would be logged. |
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* |
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*/ |
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public boolean isLoggable(LogRecord record) { |
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return super.isLoggable(record); |
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} |
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} |