groupingfilter.java

java编写的OCR软件

/*
    Jacson
    Copyright (C) 2005 Patrick Carl, pcs_org at users.sf.net
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 */

package de.spieleck.app.jacson.filter;

import de.spieleck.app.jacson.JacsonConfigException;
import de.spieleck.app.jacson.JacsonRegistry;
import de.spieleck.config.ConfigNode;
import org.apache.log4j.Logger;

/**
 * <h2>GroupingFilter</h2>
 * <h3>Description</h3>
 * <p>Filter class which concatenates the received chunks and
 * delivers them as one chunk as soon as a configurable split token
 * shows up</p>
 * <h3>Parameters</h3>
 * <table border="1" cellpadding="2" cellspacing="0">
 *  <tr>
 *   <td valign="top"><b>Attribute</b></td>
 *   <td valign="top"><b>Description</b></td>
 *   <td align="center" valign="top"><b>Required</b></td>
 *  </tr>
 *  <tr>
 *   <td valign="top">delim</td>
 *   <td valign="top">The string separating the different tokens</td>
 *   <td valign="top" align="center">No, default is ;</td>
 *  </tr>
 * </table>
 * 
 * @author pcs
 * @version $Id: GroupingFilter.java 35 2005-10-03 22:08:55Z pcs $
 * @since 0.90
 */

public class GroupingFilter extends ConstFilter {
    
    private  static final Logger logger = Logger.getLogger(GroupingFilter.class);
    
    /**
     * name of config node containing the delimiter token
     */
    public static final String DELIM_NODE = "delim";
    /**
     * default value for delimiter if none is given
     */
    public static final String DELIM_DEFAULT = ";";
    
    private String delim;
    private StringBuffer buffer = new StringBuffer(1024);
    
    GroupingFilter(String delim){
        this.delim = delim;
    }
    
    
    /**
     * initializes this object
     * @param config a ConfigNode containing the configuration
     * @param registry the JacsonRegistry
     */
    
    public void init(ConfigNode config, JacsonRegistry registry)
    throws JacsonConfigException {
        delim = config.getString(DELIM_NODE, DELIM_DEFAULT);
        super.init(config, registry);
    }
    
    /**
     * returns true if the given node is accepted by this object
     * @param node the config node to check
     * @return true if the node is accepted
     */
    public boolean accept(ConfigNode node) {
        if(logger.isDebugEnabled())
            logger.debug("GroupingFilter.init");
        return DELIM_NODE.equals(node.getName()) || super.accept(node);
    }
    
    public void putChunk(String chunk) throws de.spieleck.app.jacson.JacsonException {
        if(logger.isDebugEnabled())
            logger.debug("GroupingFilter received " + chunk);
        if(chunk == null) {
            drain.putChunk(buffer.toString());
            drain.putChunk(null);
            return;
        }
        String[] tokens = chunk.split(delim);
        if(logger.isDebugEnabled())
            logger.debug("Split chunk in " + tokens.length + " tokens");
        if(tokens.length == 1 && !chunk.endsWith(delim))
            buffer.append(chunk + "\n");
        else {
            drain.putChunk(buffer.toString() + tokens[0]);
            for(int i = 1, l = tokens.length - 1; i < l; i++){
                drain.putChunk(tokens[i]);
            }
            if(logger.isDebugEnabled())
                logger.debug("Creating new buffer");
            buffer = new StringBuffer(1024);
            if(tokens.length > 1)
                buffer.append(tokens[tokens.length - 1]);      }
    }
}