001    // SECTION-START[License Header]
002    // <editor-fold defaultstate="collapsed" desc=" Generated License ">
003    /*
004     *   Java Object Management and Configuration
005     *   Copyright (C) Christian Schulte, 2005-206
006     *   All rights reserved.
007     *
008     *   Redistribution and use in source and binary forms, with or without
009     *   modification, are permitted provided that the following conditions
010     *   are met:
011     *
012     *     o Redistributions of source code must retain the above copyright
013     *       notice, this list of conditions and the following disclaimer.
014     *
015     *     o Redistributions in binary form must reproduce the above copyright
016     *       notice, this list of conditions and the following disclaimer in
017     *       the documentation and/or other materials provided with the
018     *       distribution.
019     *
020     *   THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
021     *   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
022     *   AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
023     *   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,
024     *   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
025     *   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
026     *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
027     *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
028     *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
029     *   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
030     *
031     *   $JOMC: DefaultListener.java 4381 2012-03-04 19:29:29Z schulte2005 $
032     *
033     */
034    // </editor-fold>
035    // SECTION-END
036    package org.jomc.ri;
037    
038    import java.io.BufferedReader;
039    import java.io.IOException;
040    import java.io.PrintStream;
041    import java.io.PrintWriter;
042    import java.io.StringReader;
043    import java.io.StringWriter;
044    import java.util.logging.Level;
045    import org.jomc.spi.Listener;
046    
047    // SECTION-START[Documentation]
048    // <editor-fold defaultstate="collapsed" desc=" Generated Documentation ">
049    /**
050     * Default {@code Listener} implementation.
051     *
052     * <dl>
053     *   <dt><b>Identifier:</b></dt><dd>org.jomc.ri.DefaultListener</dd>
054     *   <dt><b>Name:</b></dt><dd>JOMC RI</dd>
055     *   <dt><b>Abstract:</b></dt><dd>No</dd>
056     *   <dt><b>Final:</b></dt><dd>No</dd>
057     *   <dt><b>Stateless:</b></dt><dd>No</dd>
058     * </dl>
059     *
060     * @author <a href="mailto:schulte2005@users.sourceforge.net">Christian Schulte</a> 1.1
061     * @version 1.1
062     */
063    // </editor-fold>
064    // SECTION-END
065    // SECTION-START[Annotations]
066    // <editor-fold defaultstate="collapsed" desc=" Generated Annotations ">
067    @javax.annotation.Generated( value = "org.jomc.tools.SourceFileProcessor 1.2.2", comments = "See http://jomc.sourceforge.net/jomc/1.2/jomc-tools-1.2.2" )
068    // </editor-fold>
069    // SECTION-END
070    public class DefaultListener implements Listener
071    {
072        // SECTION-START[DefaultListener]
073    
074        /** Constant holding the platforms line separator. */
075        private static final String LINE_SEPARATOR = System.getProperty( "line.separator", "\n" );
076    
077        /** Flag indicating the listener is enabled by default. */
078        private static volatile Boolean defaultEnabled;
079    
080        /** Flag indicating the listener is enabled. */
081        private Boolean enabled;
082    
083        /**
084         * Gets a flag indicating the listener is enabled by default.
085         * <p>The default enabled flag is controlled by system property
086         * {@code org.jomc.ri.DefaultListener.defaultEnabled} holding a value indicating the listener is enabled by default.
087         * If that property is not set, the {@code true} default is returned.</p>
088         *
089         * @return {@code true}, if the listener is enabled by default; {@code false}, if the listener is disabled by
090         * default.
091         *
092         * @see #setDefaultEnabled(java.lang.Boolean)
093         */
094        public static boolean isDefaultEnabled()
095        {
096            if ( defaultEnabled == null )
097            {
098                defaultEnabled = Boolean.valueOf( System.getProperty(
099                    "org.jomc.ri.DefaultListener.defaultEnabled", Boolean.toString( true ) ) );
100    
101            }
102    
103            return defaultEnabled;
104        }
105    
106        /**
107         * Sets the flag indicating the listener is enabled by default.
108         *
109         * @param value The new value of the flag indicating the listener is enabled by default or {@code null}.
110         *
111         * @see #isDefaultEnabled()
112         */
113        public static void setDefaultEnabled( final Boolean value )
114        {
115            defaultEnabled = value;
116        }
117    
118        /**
119         * Gets a flag indicating the listener is enabled.
120         *
121         * @return {@code true}, if the listener is enabled; {@code false}, if the listener is disabled.
122         *
123         * @see #isDefaultEnabled()
124         * @see #setEnabled(java.lang.Boolean)
125         */
126        public final boolean isEnabled()
127        {
128            if ( this.enabled == null )
129            {
130                this.enabled = isDefaultEnabled();
131            }
132    
133            return this.enabled;
134        }
135    
136        /**
137         * Sets the flag indicating the listener is enabled.
138         *
139         * @param value The new value of the flag indicating the listener is enabled or {@code null}.
140         *
141         * @see #isEnabled()
142         */
143        public final void setEnabled( final Boolean value )
144        {
145            this.enabled = value;
146        }
147    
148        /**
149         * Gets called on logging.
150         * <p>This method prints messages to the "standard" system streams. Messages with a level greater than
151         * {@code WARNING} are printed to the system error stream. All other messages are printed to the system output
152         * stream.</p>
153         *
154         * @param level The level of the event.
155         * @param message The message of the event or {@code null}.
156         * @param throwable The throwable of the event or {@code null}.
157         *
158         * @throws NullPointerException if {@code level} is {@code null}.
159         *
160         * @see #isEnabled()
161         */
162        public void onLog( final Level level, final String message, final Throwable throwable )
163        {
164            if ( level == null )
165            {
166                throw new NullPointerException( "level" );
167            }
168    
169            if ( this.isEnabled() )
170            {
171                // JDK: As of JDK 6, "System.console().writer()".
172                final PrintStream out = level.intValue() > Level.WARNING.intValue() ? System.err : System.out;
173    
174                try
175                {
176                    if ( message != null )
177                    {
178                        out.print( this.splitLines( level, message ) );
179                        out.flush();
180                    }
181    
182                    if ( throwable != null )
183                    {
184                        final StringWriter stringWriter = new StringWriter();
185                        final PrintWriter printWriter = new PrintWriter( stringWriter );
186                        throwable.printStackTrace( printWriter );
187                        printWriter.close();
188                        out.print( this.splitLines( level, stringWriter.toString() ) );
189                        out.flush();
190                    }
191                }
192                catch ( final IOException e )
193                {
194                    e.printStackTrace();
195                }
196            }
197        }
198    
199        private StringBuilder splitLines( final Level level, final String message ) throws IOException
200        {
201            BufferedReader reader = null;
202            boolean suppressExceptionOnClose = true;
203    
204            try
205            {
206                final String linePrefix = "[" + level.getLocalizedName() + "] ";
207                final StringBuilder b = new StringBuilder( message.length() );
208                reader = new BufferedReader( new StringReader( message ) );
209    
210                String line;
211                while ( ( line = reader.readLine() ) != null )
212                {
213                    b.append( linePrefix ).append( line ).append( LINE_SEPARATOR );
214                }
215    
216                suppressExceptionOnClose = false;
217                return b;
218            }
219            finally
220            {
221                try
222                {
223                    if ( reader != null )
224                    {
225                        reader.close();
226                    }
227                }
228                catch ( final IOException e )
229                {
230                    if ( !suppressExceptionOnClose )
231                    {
232                        throw e;
233                    }
234                }
235            }
236        }
237    
238        // SECTION-END
239        // SECTION-START[Constructors]
240        // <editor-fold defaultstate="collapsed" desc=" Generated Constructors ">
241        /** Creates a new {@code DefaultListener} instance. */
242        @javax.annotation.Generated( value = "org.jomc.tools.SourceFileProcessor 1.2.2", comments = "See http://jomc.sourceforge.net/jomc/1.2/jomc-tools-1.2.2" )
243        public DefaultListener()
244        {
245            // SECTION-START[Default Constructor]
246            super();
247            // SECTION-END
248        }
249        // </editor-fold>
250        // SECTION-END
251        // SECTION-START[Dependencies]
252        // SECTION-END
253        // SECTION-START[Properties]
254        // SECTION-END
255        // SECTION-START[Messages]
256        // SECTION-END
257    }