LoggerBase


1   /*
2    * The contents of this file are subject to the terms 
3    * of the Common Development and Distribution License 
4    * (the License).  You may not use this file except in
5    * compliance with the License.
6    * 
7    * You can obtain a copy of the license at 
8    * https://glassfish.dev.java.net/public/CDDLv1.0.html or
9    * glassfish/bootstrap/legal/CDDLv1.0.txt.
10   * See the License for the specific language governing 
11   * permissions and limitations under the License.
12   * 
13   * When distributing Covered Code, include this CDDL 
14   * Header Notice in each file and include the License file 
15   * at glassfish/bootstrap/legal/CDDLv1.0.txt.  
16   * If applicable, add the following below the CDDL Header, 
17   * with the fields enclosed by brackets [] replaced by
18   * you own identifying information: 
19   * "Portions Copyrighted [year] [name of copyright owner]"
20   * 
21   * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
22   */
23  
24  package com.sun.enterprise.web.logger;
25  
26  import java.beans.PropertyChangeSupport  ;
27  import java.beans.PropertyChangeListener  ;
28  import java.io.CharArrayWriter  ;
29  import java.io.PrintWriter  ;
30  import javax.servlet.ServletException  ;
31  import org.apache.catalina.Container;
32  import org.apache.catalina.LifecycleException;
33  import org.apache.catalina.Logger;
34  
35  /**
36   * Convenience base class for <b>Logger</b> implementations.  The only
37   * method that must be implemented is 
38   * <code>write(String msg, int verbosity)</code>, plus any property
39   * setting and lifecycle methods required for configuration.
40   *
41   */
42  
43  abstract class LoggerBase implements Logger {
44  
45      // ----------------------------------------------------- Instance Variables
46  
47      /**
48       * The Container with which this Logger has been associated.
49       */
50      protected Container container = null;
51  
52      /**
53       * The descriptive information about this implementation.
54       */
55      protected static final String   info =
56          "com.sun.enterprise.web.logger.LoggerBase/1.0";
57  
58      /**
59       * The property change support for this component.
60       */
61      protected PropertyChangeSupport   support = new PropertyChangeSupport  (this);
62  
63      // ------------------------------------------------------------- Properties
64  
65      /**
66       * Return the Container with which this Logger has been associated.
67       */
68      public Container getContainer() {
69          return (container);
70      }
71  
72      /**
73       * Set the Container with which this Logger has been associated.
74       *
75       * @param container The associated Container
76       */
77      public void setContainer(Container container) {
78  
79          Container oldContainer = this.container;
80          this.container = container;
81          support.firePropertyChange("container", oldContainer, this.container);
82      }
83  
84      /**
85       * Return descriptive information about this Logger implementation and
86       * the corresponding version number, in the format
87       * <code>&lt;description&gt;/&lt;version&gt;</code>.
88       */
89      public String   getInfo() {
90          return (info);
91      }
92  
93      /**
94       * Logger interface method (ignored)
95       */
96      public int getVerbosity() {
97          //Ignored
98          return -1;
99      }
100 
101     /**
102      * Logger interface method (ignored)
103      *
104      * @param verbosity The new verbosity level
105      */
106     public void setVerbosity(int verbosity) {
107         //Ignored
108     }
109 
110     // --------------------------------------------------------- Public Methods
111 
112     /**
113      * Add a property change listener to this component.
114      *
115      * @param listener The listener to add
116      */
117     public void addPropertyChangeListener(PropertyChangeListener   listener) {
118         support.addPropertyChangeListener(listener);
119     }
120 
121     /**
122      * Writes the specified message to a servlet log file, usually an event
123      * log.  The name and type of the servlet log is specific to the
124      * servlet container. 
125      *
126      * @param message A <code>String</code> specifying the message to be
127      *  written to the log file
128      */
129     public void log(String   msg) {
130         write(msg, DEBUG);
131     }
132 
133     /**
134      * Writes the specified exception, and message, to a servlet log file.
135      * The implementation of this method should call
136      * <code>log(msg, exception)</code> instead.  This method is deprecated
137      * in the ServletContext interface, but not deprecated here to avoid
138      * many useless compiler warnings.  This message will be logged
139      * unconditionally.
140      *
141      * @param exception An <code>Exception</code> to be reported
142      * @param msg The associated message string
143      */
144     public void log(Exception   exception, String   msg) {
145         log(msg, exception);
146     }
147 
148     /**
149      * Writes an explanatory message and a stack trace for a given
150      * <code>Throwable</code> exception to the servlet log file.  The name
151      * and type of the servlet log file is specific to the servlet container,
152      * usually an event log.  This message will be logged unconditionally.
153      *
154      * @param msg A <code>String</code> that describes the error or
155      *  exception
156      * @param throwable The <code>Throwable</code> error or exception
157      */
158     public void log(String   msg, Throwable   throwable) {
159         write(msg, throwable, ERROR);
160     }
161 
162     /**
163      * Writes the specified message to the servlet log file, usually an event
164      * log, if the logger is set to a verbosity level equal to or higher than
165      * the specified value for this message.
166      *
167      * @param message A <code>String</code> specifying the message to be
168      *  written to the log file
169      * @param verbosity Verbosity level of this message
170      */
171     public void log(String   message, int verbosity) {
172         write(message, verbosity);
173     }
174 
175     /**
176      * Writes the specified message and exception to the servlet log file,
177      * usually an event log, if the logger is set to a verbosity level equal
178      * to or higher than the specified value for this message.
179      *
180      * @param message A <code>String</code> that describes the error or
181      *  exception
182      * @param throwable The <code>Throwable</code> error or exception
183      * @param verbosity Verbosity level of this message
184      */
185     public void log(String   message, Throwable   throwable, int verbosity) {
186         write(message, throwable, verbosity);
187     }
188 
189     /**
190      * Remove a property change listener from this component.
191      *
192      * @param listener The listener to remove
193      */
194     public void removePropertyChangeListener(PropertyChangeListener   listener) {
195         support.removePropertyChangeListener(listener);
196     }
197 
198     protected void write(String   msg, Throwable   throwable, int verbosity) {
199         CharArrayWriter   buf = new CharArrayWriter  ();
200         PrintWriter   writer = new PrintWriter  (buf);
201         writer.println(msg);
202         throwable.printStackTrace(writer);
203         Throwable   rootCause = null;
204         if (throwable instanceof LifecycleException)
205             rootCause = ((LifecycleException) throwable).getThrowable();
206         else if (throwable instanceof ServletException  )
207             rootCause = ((ServletException  ) throwable).getRootCause();
208         if (rootCause != null) {
209             writer.println("----- Root Cause -----");
210             rootCause.printStackTrace(writer);
211         }
212         write(buf.toString(), verbosity);
213     }
214 
215     /**
216      * Logs the given message at the given verbosity level.
217      */
218     protected abstract void write(String   msg, int verbosity);
219 }
220
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