Lucene example source code file (PatternParser.java)

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Java - Lucene tags/keywords

arraylist, arraylist, elem_classes, elem_exceptions, elem_hyphen, elem_patterns, hyphenationexception, hyphenationexception, io, net, network, override, parser, patternparser, sax, string, string, stringbuilder, stringbuilder, xml

The Lucene PatternParser.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.lucene.analysis.compound.hyphenation;

// SAX
import org.xml.sax.XMLReader;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.Attributes;

// Java
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.ArrayList;

import javax.xml.parsers.SAXParserFactory;

/**
 * A SAX document handler to read and parse hyphenation patterns from a XML
 * file.
 * 
 * This class has been taken from the Apache FOP project (http://xmlgraphics.apache.org/fop/). They have been slightly modified. 
 */
public class PatternParser extends DefaultHandler implements PatternConsumer {

  XMLReader parser;

  int currElement;

  PatternConsumer consumer;

  StringBuilder token;

  ArrayList<Object> exception;

  char hyphenChar;

  String errMsg;

  static final int ELEM_CLASSES = 1;

  static final int ELEM_EXCEPTIONS = 2;

  static final int ELEM_PATTERNS = 3;

  static final int ELEM_HYPHEN = 4;

  public PatternParser() throws HyphenationException {
    token = new StringBuilder();
    parser = createParser();
    parser.setContentHandler(this);
    parser.setErrorHandler(this);
    parser.setEntityResolver(this);
    hyphenChar = '-'; // default

  }

  public PatternParser(PatternConsumer consumer) throws HyphenationException {
    this();
    this.consumer = consumer;
  }

  public void setConsumer(PatternConsumer consumer) {
    this.consumer = consumer;
  }

  /**
   * Parses a hyphenation pattern file.
   * 
   * @param filename the filename
   * @throws HyphenationException In case of an exception while parsing
   */
  public void parse(String filename) throws HyphenationException {
    parse(new InputSource(filename));
  }

  /**
   * Parses a hyphenation pattern file.
   * 
   * @param file the pattern file
   * @throws HyphenationException In case of an exception while parsing
   */
  public void parse(File file) throws HyphenationException {
    try {
      InputSource src = new InputSource(file.toURL().toExternalForm());
      parse(src);
    } catch (MalformedURLException e) {
      throw new HyphenationException("Error converting the File '" + file
          + "' to a URL: " + e.getMessage());
    }
  }

  /**
   * Parses a hyphenation pattern file.
   * 
   * @param source the InputSource for the file
   * @throws HyphenationException In case of an exception while parsing
   */
  public void parse(InputSource source) throws HyphenationException {
    try {
      parser.parse(source);
    } catch (FileNotFoundException fnfe) {
      throw new HyphenationException("File not found: " + fnfe.getMessage());
    } catch (IOException ioe) {
      throw new HyphenationException(ioe.getMessage());
    } catch (SAXException e) {
      throw new HyphenationException(errMsg);
    }
  }

  /**
   * Creates a SAX parser using JAXP
   * 
   * @return the created SAX parser
   */
  static XMLReader createParser() {
    try {
      SAXParserFactory factory = SAXParserFactory.newInstance();
      factory.setNamespaceAware(true);
      return factory.newSAXParser().getXMLReader();
    } catch (Exception e) {
      throw new RuntimeException("Couldn't create XMLReader: " + e.getMessage());
    }
  }

  protected String readToken(StringBuffer chars) {
    String word;
    boolean space = false;
    int i;
    for (i = 0; i < chars.length(); i++) {
      if (Character.isWhitespace(chars.charAt(i))) {
        space = true;
      } else {
        break;
      }
    }
    if (space) {
      // chars.delete(0,i);
      for (int countr = i; countr < chars.length(); countr++) {
        chars.setCharAt(countr - i, chars.charAt(countr));
      }
      chars.setLength(chars.length() - i);
      if (token.length() > 0) {
        word = token.toString();
        token.setLength(0);
        return word;
      }
    }
    space = false;
    for (i = 0; i < chars.length(); i++) {
      if (Character.isWhitespace(chars.charAt(i))) {
        space = true;
        break;
      }
    }
    token.append(chars.toString().substring(0, i));
    // chars.delete(0,i);
    for (int countr = i; countr < chars.length(); countr++) {
      chars.setCharAt(countr - i, chars.charAt(countr));
    }
    chars.setLength(chars.length() - i);
    if (space) {
      word = token.toString();
      token.setLength(0);
      return word;
    }
    token.append(chars);
    return null;
  }

  protected static String getPattern(String word) {
    StringBuilder pat = new StringBuilder();
    int len = word.length();
    for (int i = 0; i < len; i++) {
      if (!Character.isDigit(word.charAt(i))) {
        pat.append(word.charAt(i));
      }
    }
    return pat.toString();
  }

  protected ArrayList<Object> normalizeException(ArrayList ex) {
    ArrayList<Object> res = new ArrayList