001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    
021    package org.sonar.channel;
022    
023    import java.util.ArrayList;
024    import java.util.Arrays;
025    import java.util.List;
026    
027    import org.slf4j.Logger;
028    import org.slf4j.LoggerFactory;
029    
030    public class ChannelDispatcher<OUTPUT> extends Channel<OUTPUT> {
031    
032      private static final Logger LOG = LoggerFactory.getLogger(ChannelDispatcher.class);
033      private final boolean failIfNoChannelToConsumeOneCharacter;
034    
035      @SuppressWarnings("rawtypes")
036      private final Channel[] channels;
037    
038      /**
039       * @deprecated in version 2.9. Please use the builder() method
040       */
041      @SuppressWarnings("rawtypes")
042      @Deprecated
043      public ChannelDispatcher(List<Channel> channels) {
044        this(channels, false);
045      }
046    
047      /**
048       * @deprecated in version 2.9. Please use the builder() method
049       */
050      @SuppressWarnings("rawtypes")
051      @Deprecated
052      public ChannelDispatcher(Channel... channels) {
053        this(Arrays.asList(channels), false);
054      }
055    
056      /**
057       * @deprecated in version 2.9. Please use the builder() method
058       */
059      @SuppressWarnings("rawtypes")
060      @Deprecated
061      public ChannelDispatcher(List<Channel> channels, boolean failIfNoChannelToConsumeOneCharacter) {
062        this.channels = channels.toArray(new Channel[channels.size()]);
063        this.failIfNoChannelToConsumeOneCharacter = failIfNoChannelToConsumeOneCharacter;
064      }
065    
066      private ChannelDispatcher(Builder builder) {
067        this.channels = builder.channels.toArray(new Channel[builder.channels.size()]);
068        this.failIfNoChannelToConsumeOneCharacter = builder.failIfNoChannelToConsumeOneCharacter;
069      }
070    
071      public boolean consume(CodeReader code, OUTPUT output) {
072        int nextChar = code.peek();
073        while (nextChar != -1) {
074          boolean characterConsumed = false;
075          for (Channel<OUTPUT> channel : channels) {
076            if (channel.consume(code, output)) {
077              characterConsumed = true;
078              break;
079            }
080          }
081          if ( !characterConsumed) {
082            if (LOG.isDebugEnabled() || failIfNoChannelToConsumeOneCharacter) {
083              String message = "None of the channel has been able to handle character '" + (char) code.peek() + "' (decimal value "
084                  + code.peek() + ") at line " + code.getLinePosition() + ", column " + code.getColumnPosition();
085              if (failIfNoChannelToConsumeOneCharacter) {
086                throw new IllegalStateException(message);
087              }
088              LOG.debug(message);
089            }
090            code.pop();
091          }
092          nextChar = code.peek();
093        }
094        return true;
095      }
096    
097      Channel[] getChannels() {
098        return channels;
099      }
100    
101      /**
102       * Get a Builder instance to build a new ChannelDispatcher
103       */
104      public static Builder builder() {
105        return new Builder();
106      }
107    
108      public static final class Builder {
109    
110        private List<Channel> channels = new ArrayList<Channel>();
111        private boolean failIfNoChannelToConsumeOneCharacter = false;
112    
113        private Builder() {
114        }
115    
116        public Builder addChannel(Channel channel) {
117          channels.add(channel);
118          return this;
119        }
120    
121        public Builder addChannels(Channel... c) {
122          for (Channel channel : c) {
123            addChannel(channel);
124          }
125          return this;
126        }
127    
128        /**
129         * If this option is activated, an IllegalStateException will be thrown as soon as a character won't be consumed by any channel.
130         */
131        public Builder failIfNoChannelToConsumeOneCharacter() {
132          failIfNoChannelToConsumeOneCharacter = true;
133          return this;
134        }
135    
136        public <OUTPUT> ChannelDispatcher<OUTPUT> build() {
137          return new ChannelDispatcher<OUTPUT>(this);
138        }
139    
140      }
141    }