/* ====================================================================
* Trove - Copyright (c) 1997-2000 Walt Disney Internet Group
* ====================================================================
* The Tea Software License, Version 1.1
*
* Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Walt Disney Internet Group (http://opensource.go.com/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact opensource@dig.com.
*
* 5. Products derived from this software may not be called "Tea",
* "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
* "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
* written permission of the Walt Disney Internet Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* For more information about Tea, please see http://opensource.go.com/.
*/
package com.go.trove.log;
import java.io.*;
import java.util.*;
import java.lang.ref.WeakReference;
/******************************************************************************
* General purpose logging class that operates using a hierarchy of Logs and
* an event model. All LogEvents are categorized into one of four types:
* debugging, informational, warning and error.
*
* A log event can be generated by writing to one of the four PrintWriter
* fields provided (debug, info, warn and error), or by calling the debug,
* info, warn or error methods.
*
* Logs can have a parent Log, which by default, receives all the events
* that the Log generates or receives. If a log is disabled, it will not
* generate or propagate events.
*
* Examples:
* <pre>
* Log log = new Log("test", null);
* log.addLogListener(new LogScribe(new PrintWriter(System.out)));
*
* log.debug().println("Printing a debugging message");
* log.info("System running");
*
* Syslog.info().println("Creating child log...");
* Log child = new Log("child", Syslog.log);
* child.warn("This is a system warning...");
*
* try {
* ...
* }
* catch (Exception e) {
* child.error(e);
* }
*
* Log saved = new Log("saved", Syslog.log);
* File logDir = new File("/logs/");
* OutputStream out = new DailyFileLogStream(logDir);
* saved.addLogListener(new LogScribe(new PrintWriter(out)));
* saved.info("Saved log file initialized");
* </pre>
*
* @author Brian S O'Neill
* @version
* <!--$$Revision:--> 27 <!-- $-->, <!--$$JustDate:--> 6/28/01 <!-- $-->
* @see LogScribe
* @see Syslog
* @see LogEventParsingWriter
* @see DailyFileLogStream
*/
public class Log implements LogListener, Serializable {
private static final int ENABLED_MASK = 0x01;
private static final int DEBUG_ENABLED_MASK = 0x02;
private static final int INFO_ENABLED_MASK = 0x04;
private static final int WARN_ENABLED_MASK = 0x08;
private static final int ERROR_ENABLED_MASK = 0x10;
private final transient PrintWriter mDebug;
private final transient PrintWriter mInfo;
private final transient PrintWriter mWarn;
private final transient PrintWriter mError;
private Log mParent;
private Collection mChildren = new Vector();
private String mName;
private String mDescription;
private int mEnabledFlags = 0xfffffff;
private transient List mListeners = new Vector();
/**
* Create a new Log that inherits enabled settings from its parent. If no
* parent is specified, then the Log is fully enabled. If a parent is
* specified, then it is added automatically as a listener to this Log.
*
* @param name The optional name of this Log.
* @param parent The parent Log that will be added as a LogListener to this
* Log. If null, then this Log has no parent Log.
*/
public Log(String name, Log parent) {
this();
if (parent != null) {
mParent = parent;
parent.mChildren.add(new WeakReference(this));
mEnabledFlags = parent.mEnabledFlags;
addLogListener(parent);
}
mName = name;
mDescription = name;
}
private Log() {
LogEventParsingWriter writer;
writer = new LogEventParsingWriter(this, LogEvent.DEBUG_TYPE, this) {
public boolean isEnabled() {
return isDebugEnabled();
}
};
writer.addLogListener(this);
mDebug = new PrintWriter(writer, true);
writer = new LogEventParsingWriter(this, LogEvent.INFO_TYPE, this) {
public boolean isEnabled() {
return isInfoEnabled();
}
};
writer.addLogListener(this);
mInfo = new PrintWriter(writer, true);
writer = new LogEventParsingWriter(this, LogEvent.WARN_TYPE, this) {
public boolean isEnabled() {
return isWarnEnabled();
}
};
writer.addLogListener(this);
mWarn = new PrintWriter(writer, true);
writer = new LogEventParsingWriter(this, LogEvent.ERROR_TYPE, this) {
public boolean isEnabled() {
return isErrorEnabled();
}
};
writer.addLogListener(this);
mError = new PrintWriter(writer, true);
}
/**
* adds a listener to the root log, the log with a null parent
*/
public void addRootLogListener(LogListener listener) {
if (mParent == null) {
addLogListener(listener);
}
else {
mParent.addRootLogListener(listener);
}
}
public void removeRootLogListener(LogListener listener) {
mListeners.remove(listener);
if (mParent == null) {
removeLogListener(listener);
}
else {
mParent.removeRootLogListener(listener);
}
}
public void addLogListener(LogListener listener) {
mListeners.add(listener);
}
public void removeLogListener(LogListener listener) {
mListeners.remove(listener);
}
/**
* If this Log is enabled, then dispatch the LogEvent to all of its
* listeners as a logged message.
*/
public void logMessage(LogEvent e) {
if (isEnabled()) {
dispatchLogMessage(e);
}
}
/**
* If this Log is enabled, then dispatch the LogEvent to all of its
* listeners as a logged exception.
*/
public void logException(LogEvent e) {
if (isEnabled()) {
dispatchLogException(e);
}
}
private void dispatchLogMessage(LogEvent e) {
int size = mListeners.size();
try {
for (int i=0; i<size; i++) {
((LogListener)mListeners.get(i)).logMessage(e);
}
}
catch (IndexOutOfBoundsException ex) {
}
}
private void dispatchLogException(LogEvent e) {
int size = mListeners.size();
try {
for (int i=0; i<size; i++) {
((LogListener)mListeners.get(i)).logException(e);
}
}
catch (IndexOutOfBoundsException ex) {
}
}
/**
* Returns a PrintWriter for debug messages.
*/
public PrintWriter debug() {
return mDebug;
}
/**
* Simple method for logging a single debugging message.
*/
public synchronized void debug(String s) {
if (isEnabled() && isDebugEnabled()) {
dispatchLogMessage(new LogEvent(this, LogEvent.DEBUG_TYPE, s));
}
}
/**
* Simple method for logging a single debugging exception.
*/
public synchronized void debug(Throwable t) {
if (isEnabled() && isDebugEnabled()) {
dispatchLogException(new LogEvent(this, LogEvent.DEBUG_TYPE, t));
}
}
/**
* Returns a PrintWriter for information messages.
*/
public PrintWriter info() {
return mInfo;
}
/**
* Simple method for logging a single information message.
*/
public synchronized void info(String s) {
if (isEnabled() && isInfoEnabled()) {
dispatchLogMessage(new LogEvent(this, LogEvent.INFO_TYPE, s));
}
}
/**
* Simple method for logging a single information exception.
*/
public synchronized void info(Throwable t) {
if (isEnabled() && isInfoEnabled()) {
dispatchLogException(new LogEvent(this, LogEvent.INFO_TYPE, t));
}
}
/**
* Returns a PrintWriter for warning messages.
*/
public PrintWriter warn() {
return mWarn;
}
/**
* Simple method for logging a single warning message.
*/
public synchronized void warn(String s) {
if (isEnabled() && isWarnEnabled()) {
dispatchLogMessage(new LogEvent(this, LogEvent.WARN_TYPE, s));
}
}
/**
* Simple method for logging a single warning exception.
*/
public synchronized void warn(Throwable t) {
if (isEnabled() && isWarnEnabled()) {
dispatchLogException(new LogEvent(this, LogEvent.WARN_TYPE, t));
}
}
/**
* Returns a PrintWriter for error messages.
*/
public PrintWriter error() {
return mError;
}
/**
* Simple method for logging a single error message.
*/
public synchronized void error(String s) {
if (isEnabled() && isErrorEnabled()) {
dispatchLogMessage(new LogEvent(this, LogEvent.ERROR_TYPE, s));
}
}
/**
* Simple method for logging a single error exception.
*/
public synchronized void error(Throwable t) {
if (isEnabled() && isErrorEnabled()) {
dispatchLogException(new LogEvent(this, LogEvent.ERROR_TYPE, t));
}
}
/**
* Returns a copy of the children Logs.
*/
public Log[] getChildren() {
Collection copy;
synchronized (mChildren) {
copy = new ArrayList(mChildren.size());
Iterator it = mChildren.iterator();
while (it.hasNext()) {
Log child = (Log)((WeakReference)it.next()).get();
if (child == null) {
it.remove();
}
else {
copy.add(child);
}
}
}
return (Log[])copy.toArray(new Log[copy.size()]);
}
/**
* Returns null if this Log has no name.
*/
public String getName() {
return mName;
}
/**
* Returns a brief description of this Log. By default, returns the name.
*/
public String getDescription() {
return mDescription;
}
/**
* Set the log's description text.
*/
public void setDescription(String desc) {
mDescription = desc;
}
/**
* Returns true if this Log is enabled. If log is disabled, then no log
* events of any kind are generated or propagated to listeners.
*/
public boolean isEnabled() {
return isEnabled(ENABLED_MASK);
}
/**
* When this Log is enabled, all parent Logs are also enabled. When this
* Log is disabled, parent Logs are unaffected.
*/
public synchronized void setEnabled(boolean enabled) {
setEnabled(enabled, ENABLED_MASK);
if (enabled) {
Log parent;
if ((parent = mParent) != null) {
parent.setEnabled(true);
}
}
}
/**
* Returns true if debug events for this Log are enabled. If debug events
* are disabled, then no debug log events are generated, but they can be
* propagated to listeners.
*/
public boolean isDebugEnabled() {
return isEnabled(DEBUG_ENABLED_MASK);
}
/**
* When debug is enabled, this Log is enabled and all parent Logs are
* enabled. Disabling debug only affects this Log's debug state.
*/
public synchronized void setDebugEnabled(boolean enabled) {
setEnabled(enabled, DEBUG_ENABLED_MASK);
if (enabled) {
setEnabled(true);
}
}
/**
* Returns true if info events for this Log are enabled. If info events
* are disabled, then no info log events are generated, but they can be
* propagated to listeners.
*/
public boolean isInfoEnabled() {
return isEnabled(INFO_ENABLED_MASK);
}
/**
* When info is enabled, this Log is enabled and all parent Logs are
* enabled. Disabling info only affects this Log's info state.
*/
public synchronized void setInfoEnabled(boolean enabled) {
setEnabled(enabled, INFO_ENABLED_MASK);
if (enabled) {
setEnabled(true);
}
}
/**
* Returns true if warn events for this Log are enabled. If warn events
* are disabled, then no warn log events are generated, but they can be
* propagated to listeners.
*/
public boolean isWarnEnabled() {
return isEnabled(WARN_ENABLED_MASK);
}
/**
* When warn is enabled, this Log is enabled and all parent Logs are
* enabled. Disabling warn only affects this Log's warn state.
*/
public synchronized void setWarnEnabled(boolean enabled) {
setEnabled(enabled, WARN_ENABLED_MASK);
if (enabled) {
setEnabled(true);
}
}
/**
* Returns true if error events for this Log are enabled. If error events
* are disabled, then no error log events are generated, but they can be
* propagated to listeners.
*/
public boolean isErrorEnabled() {
return isEnabled(ERROR_ENABLED_MASK);
}
/**
* When error is enabled, this Log is enabled and all parent Logs are
* enabled. Disabling error only affects this Log's error state.
*/
public synchronized void setErrorEnabled(boolean enabled) {
setEnabled(enabled, ERROR_ENABLED_MASK);
if (enabled) {
setEnabled(true);
}
}
/**
* Understands and applies the following boolean properties. True is the
* default value if the value doesn't equal "false", ignoring case.
*
* <ul>
* <li>enabled
* <li>debug
* <li>info
* <li>warn
* <li>error
* </ul>
*/
public synchronized void applyProperties(Map properties) {
if (properties.containsKey("enabled")) {
setEnabled(!"false".equalsIgnoreCase
((String)properties.get("enabled")));
}
if (properties.containsKey("debug")) {
setDebugEnabled(!"false".equalsIgnoreCase
((String)properties.get("debug")));
}
if (properties.containsKey("info")) {
setInfoEnabled(!"false".equalsIgnoreCase
((String)properties.get("info")));
}
if (properties.containsKey("warn")) {
setWarnEnabled(!"false".equalsIgnoreCase
((String)properties.get("warn")));
}
if (properties.containsKey("error")) {
setErrorEnabled(!"false".equalsIgnoreCase
((String)properties.get("error")));
}
}
/**
* Returns a short description of this log.
*/
public String toString() {
return "Log[" + getDescription() + "]@" +
Integer.toHexString(hashCode());
}
private synchronized boolean isEnabled(int mask) {
return (mEnabledFlags & mask) == mask;
}
private synchronized void setEnabled(boolean enabled, int mask) {
if (enabled) {
mEnabledFlags |= mask;
}
else {
mEnabledFlags &= ~mask;
}
}
}