1 /*
   2  * Copyright (c) 2001, 2004, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 
  27 package java.util.logging;
  28 
  29 /**
  30  * ErrorManager objects can be attached to Handlers to process
  31  * any error that occurs on a Handler during Logging.
  32  * <p>
  33  * When processing logging output, if a Handler encounters problems
  34  * then rather than throwing an Exception back to the issuer of
  35  * the logging call (who is unlikely to be interested) the Handler
  36  * should call its associated ErrorManager.
  37  */
  38 
  39 public class ErrorManager {
  40    private boolean reported = false;
  41 
  42     /**
  43      * Create an {@code ErrorManager}.
  44      */
  45     public ErrorManager() {}
  46 
  47     /*
  48      * We declare standard error codes for important categories of errors.
  49      */
  50 
  51     /**
  52      * GENERIC_FAILURE is used for failure that don't fit
  53      * into one of the other categories.
  54      */
  55     public final static int GENERIC_FAILURE = 0;
  56     /**
  57      * WRITE_FAILURE is used when a write to an output stream fails.
  58      */
  59     public final static int WRITE_FAILURE = 1;
  60     /**
  61      * FLUSH_FAILURE is used when a flush to an output stream fails.
  62      */
  63     public final static int FLUSH_FAILURE = 2;
  64     /**
  65      * CLOSE_FAILURE is used when a close of an output stream fails.
  66      */
  67     public final static int CLOSE_FAILURE = 3;
  68     /**
  69      * OPEN_FAILURE is used when an open of an output stream fails.
  70      */
  71     public final static int OPEN_FAILURE = 4;
  72     /**
  73      * FORMAT_FAILURE is used when formatting fails for any reason.
  74      */
  75     public final static int FORMAT_FAILURE = 5;
  76 
  77     /**
  78      * The error method is called when a Handler failure occurs.
  79      * <p>
  80      * This method may be overridden in subclasses.  The default
  81      * behavior in this base class is that the first call is
  82      * reported to System.err, and subsequent calls are ignored.
  83      *
  84      * @param msg    a descriptive string (may be null)
  85      * @param ex     an exception (may be null)
  86      * @param code   an error code defined in ErrorManager
  87      */
  88     public synchronized void error(String msg, Exception ex, int code) {
  89         if (reported) {
  90             // We only report the first error, to avoid clogging
  91             // the screen.
  92             return;
  93         }
  94         reported = true;
  95         String text = "java.util.logging.ErrorManager: " + code;
  96         if (msg != null) {
  97             text = text + ": " + msg;
  98         }
  99         System.err.println(text);
 100         if (ex != null) {
 101             ex.printStackTrace();
 102         }
 103     }
 104 }