PR: 18410
Obtained from:
Submitted by: Daniel Naber
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@150267 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Otis Gospodnetic 2004-03-30 15:44:58 +00:00
parent 16146cbd32
commit 25f78d7cc2
3 changed files with 61 additions and 59 deletions

View File

@ -17,12 +17,14 @@ package org.apache.lucene.analysis.de;
*/
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.LowerCaseFilter;
import org.apache.lucene.analysis.StopFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.IOException;
import java.util.HashSet;
@ -93,7 +95,7 @@ public class GermanAnalyzer extends Analyzer {
* Builds an analyzer with the given stop words.
*/
public GermanAnalyzer(File stopwords) throws IOException {
stopSet = new HashSet(WordlistLoader.getWordtable(stopwords).keySet());
stopSet = WordlistLoader.getWordSet(stopwords);
}
/**
@ -114,19 +116,19 @@ public class GermanAnalyzer extends Analyzer {
* Builds an exclusionlist from the words contained in the given file.
*/
public void setStemExclusionTable(File exclusionlist) throws IOException {
exclusionSet = new HashSet(WordlistLoader.getWordtable(exclusionlist).keySet());
exclusionSet = WordlistLoader.getWordSet(exclusionlist);
}
/**
* Creates a TokenStream which tokenizes all the text in the provided Reader.
*
* @return A TokenStream build from a StandardTokenizer filtered with
* StandardFilter, StopFilter, GermanStemFilter
* StandardFilter, LowerCaseFilter, StopFilter, GermanStemFilter
*/
public TokenStream tokenStream(String fieldName, Reader reader) {
TokenStream result = new StandardTokenizer(reader);
result = new StandardFilter(result);
// shouldn't there be a lowercaser before stop word filtering?
result = new LowerCaseFilter(result);
result = new StopFilter(result, stopSet);
result = new GermanStemFilter(result, exclusionSet);
return result;

View File

@ -31,11 +31,6 @@ public class GermanStemmer
*/
private StringBuffer sb = new StringBuffer();
/**
* Indicates if a term is handled as a noun.
*/
private boolean uppercase = false;
/**
* Amount of characters that are removed with <tt>substitute()</tt> while stemming.
*/
@ -49,8 +44,6 @@ public class GermanStemmer
*/
protected String stem( String term )
{
// Mark a possible noun.
uppercase = Character.isUpperCase( term.charAt( 0 ) );
// Use lowercase for medium stemming.
term = term.toLowerCase();
if ( !isStemmable( term ) )
@ -115,7 +108,7 @@ public class GermanStemmer
buffer.deleteCharAt( buffer.length() - 1 );
}
// "t" occurs only as suffix of verbs.
else if ( buffer.charAt( buffer.length() - 1 ) == 't' && !uppercase ) {
else if ( buffer.charAt( buffer.length() - 1 ) == 't' ) {
buffer.deleteCharAt( buffer.length() - 1 );
}
else {

View File

@ -20,66 +20,42 @@ import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
/**
* Loads a text file and adds every line as an entry to a Hashtable. Every line
* should contain only one word.
* Loader for text files that represent a list of stopwords.
*
* @author Gerhard Schwarz
* @version $Id$
* @todo refactor to convert to Sets instead of Hashtable
*
* @todo this is not specific to German, it should be moved up
*/
public class WordlistLoader {
/**
* @param path Path to the wordlist
* @param wordfile Name of the wordlist
*/
public static Hashtable getWordtable(String path, String wordfile) throws IOException {
if (path == null || wordfile == null) {
return new Hashtable();
}
return getWordtable(new File(path, wordfile));
}
/**
* @param wordfile Complete path to the wordlist
*/
public static Hashtable getWordtable(String wordfile) throws IOException {
if (wordfile == null) {
return new Hashtable();
}
return getWordtable(new File(wordfile));
}
/**
* Loads a text file and adds every line as an entry to a HashSet (omitting
* leading and trailing whitespace). Every line of the file should contain only
* one word. The words need to be in lowercase if you make use of an
* Analyzer which uses LowerCaseFilter (like GermanAnalyzer).
*
* @param wordfile File containing the wordlist
* @todo Create a Set version of this method
* @return A HashSet with the file's words
*/
public static Hashtable getWordtable(File wordfile) throws IOException {
if (wordfile == null) {
return new Hashtable();
}
Hashtable result = null;
public static HashSet getWordSet(File wordfile) throws IOException {
HashSet result = new HashSet();
FileReader freader = null;
LineNumberReader lnr = null;
try {
freader = new FileReader(wordfile);
lnr = new LineNumberReader(freader);
String word = null;
String[] stopwords = new String[100];
int wordcount = 0;
while ((word = lnr.readLine()) != null) {
wordcount++;
if (wordcount == stopwords.length) {
String[] tmp = new String[stopwords.length + 50];
System.arraycopy(stopwords, 0, tmp, 0, wordcount);
stopwords = tmp;
result.add(word.trim());
}
stopwords[wordcount - 1] = word;
}
result = makeWordTable(stopwords, wordcount);
} finally {
finally {
if (lnr != null)
lnr.close();
if (freader != null)
@ -89,15 +65,46 @@ public class WordlistLoader {
}
/**
* Builds the wordlist table.
* @param path Path to the wordlist
* @param wordfile Name of the wordlist
*
* @param words Word that where read
* @param length Amount of words that where read into <tt>words</tt>
* @deprecated Use {@link #getWordSet(File)} getWordSet(File)} instead
*/
private static Hashtable makeWordTable(String[] words, int length) {
Hashtable table = new Hashtable(length);
for (int i = 0; i < length; i++) {
table.put(words[i], words[i]);
public static Hashtable getWordtable(String path, String wordfile) throws IOException {
return getWordtable(new File(path, wordfile));
}
/**
* @param wordfile Complete path to the wordlist
*
* @deprecated Use {@link #getWordSet(File)} getWordSet(File)} instead
*/
public static Hashtable getWordtable(String wordfile) throws IOException {
return getWordtable(new File(wordfile));
}
/**
* @param wordfile File object that points to the wordlist
*
* @deprecated Use {@link #getWordSet(File)} getWordSet(File)} instead
*/
public static Hashtable getWordtable(File wordfile) throws IOException {
HashSet wordSet = (HashSet)getWordSet(wordfile);
Hashtable result = makeWordTable(wordSet);
return result;
}
/**
* Builds a wordlist table, using words as both keys and values
* for backward compatibility.
*
* @param wordSet stopword set
*/
private static Hashtable makeWordTable(HashSet wordSet) {
Hashtable table = new Hashtable();
for (Iterator iter = wordSet.iterator(); iter.hasNext();) {
String word = (String)iter.next();
table.put(word, word);
}
return table;
}