// **********************************************************************
//
// <copyright>
//
// BBN Technologies
// 10 Moulton Street
// Cambridge, MA 02138
// (617) 873-8000
//
// Copyright (C) BBNT Solutions LLC. All rights reserved.
//
// </copyright>
// **********************************************************************
//
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/util/Debug.java,v $
// $RCSfile: Debug.java,v $
// $Revision: 1.6 $
// $Date: 2004/12/08 01:10:45 $
// $Author: dietrick $
//
// **********************************************************************
package com.bbn.openmap.util;
import java.applet.Applet;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
/**
* An abstract class that presents a static interface for debugging
* output. It also provides a way to direct output into a log. There
* are two types of output - the regular output information, and the
* error information, and they can be handled separately. There are
* two differences between the two - the error file only gets created
* if there is an error, and the error messages have a header and a
* tail surrounding the messages, making them easier to spot. If the
* output and error file are set to be the same (setLogFile()), then
* that file is created automatically, regardless of anything being
* put into it.
* <p>
* Debugging output is turned on or off by system properties for
* applications, or parameters for applets.
* <p>
* A programmer can use code like the following:
* <p>
* <pre><code>
*
* if (Debug.debugging("foo")) {
* System.out.println("Got " + nbytes + " bytes of data.");
* }
*
* </code></pre>
* <p>
* The message gets printed when the application is run with
* <code>-Ddebug.foo</code> or when the applet gets run with:
* <pre>
*
* <code><param name=debug.foo value=></code>
*
* </pre>
* The special token <code>debug.all</code> turns on all debugging
* for both applets and applications.
*
* @author Tom Mitchell (tmitchell@bbn.com)
* @author $Author: dietrick $
* @version $Revision: 1.6 $, $Date: 2004/12/08 01:10:45 $
*/
public abstract class Debug {
public static String ERROR_HEADER = "\n*** ERROR ***";
public static String ERROR_TAIL = "*************";
/**
* Don't allow construction, all methods are static.
*/
private Debug() {
}
/**
* Globally enable or disable debugging.
*/
public static final boolean On = true;
/**
* The stream where debugging output should go. Default is System.out.
*/
public static PrintStream out = System.out;
/**
* The stream where debugging error messages should go. Default is
* System.err. Use the function Debug.error to write to it, in case you also
* want to direct output to a file.
*/
protected static PrintStream err = System.err;
/**
* The File for logging errors.
*/
protected static File errorFile = null;
/**
* The flag for whether the output stream should still be notified if
* logging output.
*/
protected static boolean notifyOut = true;
/**
* The flag for whether the err stream should still be notified if logging
* errors.
*/
protected static boolean notifyErr = true;
/**
* The DataOutputStream for logging output.
*/
protected static DataOutputStream outputLog = null;
/**
* The DataOutputStream for logging errors.
*/
protected static DataOutputStream errorLog = null;
/**
* Flag to have the errors appended to the error log.
*/
protected static boolean errorAppend = false;
/**
* Flag to indicate whether all debug messages should get printed. This is
* shorthand for defining all the debug symbols.
*/
public static boolean debugAll = false;
/**
* The user specified flag to indicate all debugging is on. Default is
* "all".
*/
public static String debugAllToken = "all";
private static Hashtable dbgTable = new Hashtable();
private static String debugTokenHeader = "debug.";
/**
* Initialize debugging for the given applet. Applets must pass an array of
* parameters because the applet Parameters list cannot be accessed in
* whole, only queried. The parameters list looks something like this:
*
* <pre>
* <code>
* String[] debugTokens = { "debug.debug", // com.bbn.openmap.Debug
* "debug.openmap", // com.bbn.openmap.client.OpenMap
* "debug.mappanel", // com.bbn.openmap.awt.MapPanel
* "debug.awt", // com.bbn.openmap.awt.*
* "debug.map", // com.bbn.openmap.Map
* "debug.layer", // com.bbn.openmap.Layer
* "debug.proj", // com.bbn.openmap.proj.*
* "debug.spec", // com.bbn.openmap.spec.*
* "debug.env" // com.bbn.openmap.Environment
* };
* </code>
* </pre>
*
* @param applet The applet
* @param parameters The debugging flags to look for in the applet's
* parameters list
*/
public static void init(Applet applet, String[] parameters) {
if (applet == null) {
// handle a SecurityException in case we are an applet
// but no applet was passed as an argument.
try {
init(System.getProperties());
} catch (SecurityException e) {
}
} else if (parameters != null) {
try {
for (int i = 0; i < parameters.length; i++) {
String pname = parameters[i];
if (pname.startsWith(debugTokenHeader)
&& (applet.getParameter(parameters[i]) != null)) {
String token = pname.substring(debugTokenHeader.length());
dbgTable.put(token, Boolean.TRUE);
}
}
// look for special debug.all token!
if (applet.getParameter(debugTokenHeader + debugAllToken) != null) {
dbgTable.put(debugAllToken, Boolean.TRUE);
}
} catch (NullPointerException npe) {
}
}
Debug.postInit();
}
/**
* Initialize debugging for an application. Debugging symbols are detected
* in the given properties list, and must have the form "debug.X", where X
* is a debug token used in the application.
*
* @param p A properties list, usually System.getProperties()
*/
public static void init(Properties p) {
Enumeration e = p.propertyNames();
while (e.hasMoreElements()) {
String name = e.nextElement().toString();
if (name.startsWith(debugTokenHeader)) {
String token = name.substring(debugTokenHeader.length());
dbgTable.put(token, Boolean.TRUE);
}
}
Debug.postInit();
}
/**
* Initialize debugging from the system properties.
*/
public static void init() {
Properties p;
try {
p = System.getProperties();
} catch (java.security.AccessControlException ace) {
p = new Properties();
}
init(p);
}
/**
* Common inits, regardless of applet or application.
*/
private static void postInit() {
debugAll = dbgTable.containsKey(debugAllToken);
}
/**
* Indicates if the debugging for the named token is on or off.
*
* @param token a candidate token
* @return true if debugging is on, false otherwise.
*/
public static boolean debugging(String token) {
return Debug.On && (debugAll || dbgTable.containsKey(token));
}
/**
* Installs a new debug token
*
* @param dbgToken token name
*/
public static void put(String dbgToken) {
dbgTable.put(dbgToken, Boolean.TRUE);
}
/**
* Rremoves a debug token
*
* @param dbgToken token name
*/
public static void remove(String dbgToken) {
dbgTable.remove(dbgToken);
}
/**
* Prints <code>message</code> if <code>dbgToken</code> debugging is on.
* NOTE, WARNING!: this is a potentially expensive method if you pass a
* message String composed of many concatenated pairs. For example, like:
* <br>
* `onceStr+" "+uponStr+" a "+timeStr+", "+ ... +"\nThe end."' <br>
* Instead you should do:
*
* <pre>
* <code>
*
* if (Debug.debugging(dbgToken)) {
* Debug.output(onceStr+" "+uponStr+" a "+timeStr+", "+ ... +"\nThe end.");
* }
*
* </code>
* </pre>
*
* @param dbgToken a token to be tested by debugging()
* @param message a message to be printed
*/
public static void message(String dbgToken, String message) {
if (Debug.On && Debug.debugging(dbgToken)) {
Debug.output(message);
}
}
/**
* Sets the debugging output stream to the named stream.
*
* @param out the desired debugging output stream
*/
public static void setPrintStream(PrintStream out) {
Debug.out = out;
}
/**
* Accessor for the current debugging output stream.
*
* @return the current debugging output stream.
*/
public static PrintStream getPrintStream() {
return out;
}
/**
* Provide a file to log output. This can be in conjunction with the output
* stream, or instead of it. Will overwrite the file, if it exists.
*
* @param file the file to use for the error log.
* @param alsoToOutStream true if the out stream should still provide
* output, in addition to logging the output
*/
public static void directOutput(File file, boolean alsoToOutStream) {
try {
directOutput(new FileOutputStream(file), alsoToOutStream);
} catch (IOException ioe) {
// If something goes wrong, set the output to the
// System.out only, and hope someone sees it.
notifyOut = true;
out = System.out;
error("Debug: can't set up <" + file + "> for log file! \n" + ioe);
return;
}
}
/**
* Provide a file to log output. This can be in conjunction with the output
* stream, or instead of it.
*
* @param filename the file to use for the error log.
* @param append if true, log the output at the end of the file, instead of
* the beginning.
* @param alsoToOutStream true if the out stream should still provide
* output, in addition to logging the output.
*/
public static void directOutput(String filename, boolean append, boolean alsoToOutStream) {
try {
directOutput(new FileOutputStream(filename, append), alsoToOutStream);
} catch (IOException ioe) {
// If something goes wrong, set the output to the
// System.out only, and hope someone sees it.
notifyOut = true;
out = System.out;
error("Debug: can't set up <" + filename + "> for log file! \n" + ioe);
return;
}
}
/**
* Provide a DataOutputStream to log output. This can be in conjunction with
* the output stream, or instead of it.
*
* @param os the OutputStream that's handling outputlogging.
* @param alsoToOutStream true if the out stream should still provide
* output, in addition to logging the output.
*/
public static void directOutput(OutputStream os, boolean alsoToOutStream) {
outputLog = new DataOutputStream(os);
notifyOut = alsoToOutStream;
}
/**
* Sets the error output stream to the named stream.
*
* @param err the desired error output stream
*/
public static void setErrorStream(PrintStream err) {
Debug.err = err;
}
/**
* Accessor for the current error output stream.
*
* @return the current error output stream.
*/
public static PrintStream getErrorStream() {
return err;
}
/**
* Provide a file to log errors. This can be in conjunction with the
* errorstream, or instead of it.
*
* @param file the file to use for the error log.
* @param alsoToErrStream true if the err stream should still provide
* output, in addition to logging the errors.
*/
public static void directErrors(File file, boolean alsoToErrStream) {
errorFile = file;
notifyErr = alsoToErrStream;
}
/**
* Provide a file to log errors. This can be in conjunction with the
* errorstream, or instead of it.
*
* @param filename the file to use for the error log.
* @param append if true, log the output at the end of the file, instead of
* the beginning.
* @param alsoToErrStream true if the err stream should still provide
* output, in addition to logging the errors.
*/
public static void directErrors(String filename, boolean append, boolean alsoToErrStream) {
errorAppend = append;
errorFile = new File(filename);
notifyErr = alsoToErrStream;
}
/**
* Provide a DataOutputStream to log errors. This can be in conjunction with
* the errorstream, or instead of it.
*
* @param os the DataOutputStream handling error logging.
* @param alsoToErrStream true if the err stream should still provide
* output, in addition to logging the errors.
*/
public static void directErrors(OutputStream os, boolean alsoToErrStream) {
errorLog = new DataOutputStream(os);
notifyErr = alsoToErrStream;
}
/**
* Handle error messages, buy writing them to an error log, if that has been
* set up, and/or to the error stream, if requested. The special thing about
* error output is that the error is framed with a header and a tail,
* hopefully to make it easier for someone to spot in the log.
*
* @param errorString the string to write as an error.
*/
public static void error(String errorString) {
try {
if (errorLog == null) {
// If no errors have happened yet, this will get run.
if (errorFile != null) {
FileOutputStream log = new FileOutputStream(errorFile.getPath(), errorAppend);
errorLog = new DataOutputStream(log);
// Lets make introductions into the error file,
// shall we?
errorLog.writeBytes("\n");
errorLog.writeBytes(getMapBeanMessage());
errorLog.writeBytes("\n");
errorLog.writeBytes("ERROR log file - "
+ java.util.Calendar.getInstance().getTime());
errorLog.writeBytes("\n");
errorLog.writeBytes(ERROR_TAIL);
errorLog.writeBytes(ERROR_TAIL);
errorLog.writeBytes(ERROR_TAIL);
errorLog.writeBytes("\n");
/////////////////////
errorLog.writeBytes(ERROR_HEADER);
errorLog.writeBytes(errorString);
errorLog.writeBytes("\n");
errorLog.writeBytes(ERROR_TAIL);
errorLog.writeBytes("\n");
}
} else {
// With the log already set up, this should get run.
errorLog.writeBytes(ERROR_HEADER);
errorLog.writeBytes("\n");
errorLog.writeBytes(errorString);
errorLog.writeBytes("\n");
errorLog.writeBytes(ERROR_TAIL);
errorLog.writeBytes("\n");
}
} catch (IOException ioe) {
// If something goes wrong, set the output to the
// System.err only, and hope someone sees it.
errorFile = null;
notifyErr = true;
err = System.err;
err.println(ERROR_HEADER);
err.println("Debug: error writing <" + errorString + "> to log! \n" + ioe);
err.println(ERROR_TAIL);
return;
}
// Write to the error stream if required.
if (notifyErr) {
err.println(ERROR_HEADER);
err.println(errorString);
err.println(ERROR_TAIL);
}
}
/**
* A reflective method to get the copyright message from the MapBean without
* having to actually compile the MapBean when Debug is compiled.\
*
* @return MapBean message.
*/
public static String getMapBeanMessage() {
String message = "";
try {
Class mbClass = Class.forName("com.bbn.openmap.MapBean");
java.lang.reflect.Method crMessage = mbClass.getDeclaredMethod("getCopyrightMessage", (Class[]) null);
message = (String) crMessage.invoke(mbClass, (Object[]) null);
} catch (java.lang.reflect.InvocationTargetException ite) {
System.out.println(ite.getMessage());
} catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage());
} catch (IllegalAccessException iae2) {
System.out.println(iae2.getMessage());
} catch (NoSuchMethodException nme) {
System.out.println(nme.getMessage());
} catch (NullPointerException npe) {
System.out.println(npe.getMessage());
} catch (SecurityException se) {
System.out.println(se.getMessage());
} catch (ClassNotFoundException cnfe) {
System.out.println(cnfe.getMessage());
}
return message;
}
/** println to output. */
public static void output() {
Debug.output("");
}
/**
* Handle output messages, buy writing them to an output log, if that has
* been set up, and/or to the output stream, if requested.
*
* @param outputString the string to write as output.
*/
public static void output(String outputString) {
try {
if (outputLog != null) {
outputLog.writeBytes(outputString);
outputLog.writeBytes("\n");
}
} catch (IOException ioe) {
// If something goes wrong, set the output to the
// System.out only, and hope someone sees it.
notifyOut = true;
out = System.out;
error("Debug: output writing <" + outputString + "> to log! \n" + ioe);
return;
}
// Write to the output stream if required.
if (notifyOut) {
out.println(outputString);
}
}
/**
* Provide a file to log output. This can be in conjunction with the
* streams, or instead of them. This basically sets the output log and the
* error log to be the same thing.
*
* @param file the file to use for the error log.
* @param alsoToStreams true if the streams should still provide output, in
* addition to logging the output.
*/
public static void setLog(File file, boolean alsoToStreams) {
try {
FileOutputStream logStream = new FileOutputStream(file);
setLog(logStream, alsoToStreams);
} catch (IOException ioe) {
// If something goes wrong, set the output to the
// System streams only, and hope someone sees it.
resetOutput();
error("IOException trying to create a log file.\n" + ioe);
}
}
/**
* Provide an output stream to log output. This can be in conjunction with
* the streams, or instead of them. This basically sets the output log and
* the error log to be the same thing.
*
* @param logStream the output stream for output.
* @param alsoToStreams true if the streams should still provide output, in
* addition to logging the output.
*/
public static void setLog(OutputStream logStream, boolean alsoToStreams) {
DataOutputStream dos = new DataOutputStream(logStream);
outputLog = dos;
errorLog = dos;
// Wrap up loose ends - if something happens to the
// logStream, we'll just shut down logging, and force
// everything to the output streams.
errorFile = null;
notifyErr = alsoToStreams;
notifyOut = alsoToStreams;
}
/**
* Reset the logging to the output.
*/
public static void resetOutput() {
// If something goes wrong, set the output to the
// System streams only, and hope someone sees it.
notifyOut = true;
errorFile = null;
notifyErr = true;
err = System.err;
out = System.out;
}
/**
* Dummy function to illustrate usage of the debugging class.
*/
public static void sampleUsage() {
if (Debug.On && Debug.debugging("debug")) {
Debug.output("debug message");
} else {
Debug.output("try again");
}
}
/**
* <code>main</code> routine used in unit testing.
*
* @param args none expected
*/
public static void main(String args[]) {
Debug.init(System.getProperties());
Debug.sampleUsage();
}
}