removes copy of PorterStemmer from summarizer component now relying on OpenNLP tools' default `PorterStemmer` (DRY) (#99)
improves `DefaultDocProcessor` to better re-use the stemmer instance and make use of pre-compiled Pattern
improves formatting along the path
diff --git a/summarizer/src/main/java/opennlp/summarization/Sentence.java b/summarizer/src/main/java/opennlp/summarization/Sentence.java
index fad8cf1..07079b2 100755
--- a/summarizer/src/main/java/opennlp/summarization/Sentence.java
+++ b/summarizer/src/main/java/opennlp/summarization/Sentence.java
@@ -23,8 +23,8 @@
import java.util.Locale;
import java.util.Objects;
-import opennlp.summarization.preprocess.PorterStemmer;
import opennlp.summarization.preprocess.StopWords;
+import opennlp.tools.stemmer.PorterStemmer;
/**
* A representation of a sentence geared toward pagerank and summarization.
@@ -159,16 +159,15 @@
StringBuilder b = new StringBuilder();
wrdItr.setText(stringVal);
for(int wrdEnd = wrdItr.next(); wrdEnd != BreakIterator.DONE;
- wrdStrt = wrdEnd, wrdEnd = wrdItr.next())
- {
+ wrdStrt = wrdEnd, wrdEnd = wrdItr.next()) {
String word = this.getStringVal().substring(wrdStrt, wrdEnd);//words[i].trim();
word = word.replace("\"|'","");
- //Skip stop words and stem the word.
+ // Skip stop words and stem the word.
if(sw.isStopWord(word)) continue;
-
+
stemmer.stem(word);
- b.append(stemmer);
+ b.append(stemmer.toString());
b.append(SPACE);
}
return b.toString();
diff --git a/summarizer/src/main/java/opennlp/summarization/meta/MetaSummarizer.java b/summarizer/src/main/java/opennlp/summarization/meta/MetaSummarizer.java
index e6eca05..d4743ce 100644
--- a/summarizer/src/main/java/opennlp/summarization/meta/MetaSummarizer.java
+++ b/summarizer/src/main/java/opennlp/summarization/meta/MetaSummarizer.java
@@ -33,7 +33,8 @@
import opennlp.summarization.textrank.TextRankSummarizer;
import opennlp.summarization.DocProcessor;
-/*
+
+/**
* A summarizer that combines results from the text rank algorithm and the lexical chaining algorithm.
* It runs both algorithm and uses the lexical chains to identify the main topics and relative importance
* and the text rank to pick sentences from lexical chains.
@@ -60,9 +61,8 @@
// Rank sentences by merging the scores from lexical chaining and text rank.
// maxWords -1 indicates rank all sentences.
public int getBestSent(LexicalChain l, Hashtable<Integer, Score> pageRankScores) {
- double bestScore = 0; int bestStr=-1;
- for(Sentence s : l.getSentences())
- {
+ double bestScore = 0; int bestStr = -1;
+ for(Sentence s : l.getSentences()) {
Score sc = pageRankScores.get(s.getSentId());
if(sc!=null && sc.getScore() > bestScore)
{
@@ -115,12 +115,10 @@
}
//Default Summarization using only lexical chains..
- public String summarize(String article, int maxWords)
- {
+ public String summarize(String article, int maxWords) {
//Build lexical Chains..
List<Sentence> sent = dp.getSentencesFromStr(article);
-
- List<Score>finalSc = rankSentences(article, sent, maxWords);
+ List<Score> finalSc = rankSentences(article, sent, maxWords);
StringBuilder sb = new StringBuilder();
for (Score score : finalSc) {
diff --git a/summarizer/src/main/java/opennlp/summarization/preprocess/DefaultDocProcessor.java b/summarizer/src/main/java/opennlp/summarization/preprocess/DefaultDocProcessor.java
index c54f76e..f4e1a0e 100755
--- a/summarizer/src/main/java/opennlp/summarization/preprocess/DefaultDocProcessor.java
+++ b/summarizer/src/main/java/opennlp/summarization/preprocess/DefaultDocProcessor.java
@@ -29,11 +29,13 @@
import java.util.Hashtable;
import java.util.logging.Level;
import java.util.logging.Logger;
+import java.util.regex.Pattern;
import opennlp.summarization.Sentence;
import opennlp.summarization.DocProcessor;
import opennlp.tools.sentdetect.SentenceDetectorME;
import opennlp.tools.sentdetect.SentenceModel;
+import opennlp.tools.stemmer.PorterStemmer;
import opennlp.tools.stemmer.Stemmer;
/**
@@ -41,15 +43,19 @@
*/
public class DefaultDocProcessor implements DocProcessor {
private SentenceModel sentModel;
- private Stemmer stemmer;
- private StopWords sw;
+ private final Stemmer stemmer;
+
+ private final static Pattern REPLACEMENT_PATTERN =
+ Pattern.compile("&#?[0-9 a-z A-Z][0-9 a-z A-Z][0-9 a-z A-Z]?;");
// Sentence fragmentation to use..
private static final int OPEN_NLP = 1;
private static final int SIMPLE = 2;
- private static final int SENTENCE_FRAG= OPEN_NLP;
+ private static final int SENTENCE_FRAG = OPEN_NLP;
public DefaultDocProcessor(InputStream fragModelFile) {
+ stemmer = new PorterStemmer();
+
try (InputStream modelIn = new BufferedInputStream(fragModelFile)){
sentModel = new SentenceModel(modelIn);
} catch(Exception ex){
@@ -65,7 +71,6 @@
Hashtable<String, List<Integer>> iidx, List<String> processedSent) {
int oldSentEndIdx = 0;
int sentEndIdx = 0;
- Stemmer stemmer = new PorterStemmer();
StopWords sw = StopWords.getInstance();
BreakIterator iterator = BreakIterator.getSentenceInstance(Locale.US);
BreakIterator wrdItr = BreakIterator.getWordInstance(Locale.US);
@@ -73,8 +78,7 @@
int start = iterator.first();
int sentCnt = 0;
- for (int end = iterator.next(); end != BreakIterator.DONE; start = end, end = iterator.next())
- {
+ for (int end = iterator.next(); end != BreakIterator.DONE; start = end, end = iterator.next()) {
String sentence = str.substring(start,end);//str.substring(oldSentEndIdx, sentEndIdx).trim();
//Add the sentence as-is; do any processing at the word level
@@ -100,7 +104,7 @@
{
if(stemedWrd.length()>1)
{
- List<Integer> sentList= iidx.get(stemedWrd);
+ List<Integer> sentList = iidx.get(stemedWrd);
if(sentList==null)
{
sentList = new ArrayList<>();
@@ -130,7 +134,7 @@
while ((nextLine = lnr.readLine()) != null) {
String trimmedLine = nextLine.trim();
if (!trimmedLine.isEmpty() ) {
- docBuffer.append(trimmedLine.replaceAll("&#?[0-9 a-z A-Z][0-9 a-z A-Z][0-9 a-z A-Z]?;", "")).append(" ");
+ docBuffer.append(REPLACEMENT_PATTERN.matcher(trimmedLine).replaceAll("")).append(" ");
}
}
} catch (Exception ex) {
@@ -154,8 +158,7 @@
List<String> cleanedSents = new ArrayList<>();
this.getSentences(trimmedLine, sents, null, cleanedSents);
int paraPos = 1;
- for(String sen:sents)
- {
+ for(String sen:sents) {
Sentence s = new Sentence();
s.setSentId(sentNo++);
s.setParagraph(paraNo);
diff --git a/summarizer/src/main/java/opennlp/summarization/preprocess/PorterStemmer.java b/summarizer/src/main/java/opennlp/summarization/preprocess/PorterStemmer.java
deleted file mode 100755
index 3b787f6..0000000
--- a/summarizer/src/main/java/opennlp/summarization/preprocess/PorterStemmer.java
+++ /dev/null
@@ -1,388 +0,0 @@
-/*
- * 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 opennlp.summarization.preprocess;
-
-/*
-
- Porter stemmer in Java. The original paper is in
-
- Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14,
- no. 3, pp 130-137,
-
- See also http://www.tartarus.org/~martin/PorterStemmer
-
- History:
-
- Release 1
-
- Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below.
- The words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1]
- is then out outside the bounds of b.
-
- Release 2
-
- Similarly,
-
- Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below.
- 'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and
- b[j] is then outside the bounds of b.
-
- Release 3
-
- Considerably revised 4/9/00 in the light of many helpful suggestions
- from Brian Goetz of Quiotix Corporation (brian@quiotix.com).
-
- Release 4
-
-*/
-
-import opennlp.tools.stemmer.Stemmer;
-
-/**
- * Stemmer, implementing the Porter Stemming Algorithm
- * <p>
- * The Stemmer class transforms a word into its root form. The input
- * word can be provided a character at time (by calling add()), or at once
- * by calling one of the various stem(something) methods.
- */
-public class PorterStemmer implements Stemmer {
-
- private char[] b;
- private int i, /* offset into b */
- i_end, /* offset to end of stemmed word */
- j, k;
- private static final int INC = 50;
- /* unit of size whereby b is increased */
- public PorterStemmer() {
- b = new char[INC];
- i = 0;
- i_end = 0;
- }
-
- /**
- * Add a character to the word being stemmed. When you are finished
- * adding characters, you can call stem(void) to stem the word.
- */
-
- public void add(char ch) {
- if (i == b.length)
- { char[] new_b = new char[i+INC];
- for (int c = 0; c < i; c++) new_b[c] = b[c];
- b = new_b;
- }
- b[i++] = ch;
- }
-
-
- /** Adds wLen characters to the word being stemmed contained in a portion
- * of a char[] array. This is like repeated calls of add(char ch), but
- * faster.
- */
-
- public void add(char[] w, int wLen) {
- if (i+wLen >= b.length)
- { char[] new_b = new char[i+wLen+INC];
- for (int c = 0; c < i; c++) new_b[c] = b[c];
- b = new_b;
- }
- for (int c = 0; c < wLen; c++) b[i++] = w[c];
- }
-
- /**
- * After a word has been stemmed, it can be retrieved by toString(),
- * or a reference to the internal buffer can be retrieved by getResultBuffer
- * and getResultLength (which is generally more efficient.)
- */
- @Override
- public String toString() { return new String(b,0,i_end); }
-
- /**
- * Returns the length of the word resulting from the stemming process.
- */
- public int getResultLength() { return i_end; }
-
- /**
- * Returns a reference to a character buffer containing the results of
- * the stemming process. You also need to consult getResultLength()
- * to determine the length of the result.
- */
- public char[] getResultBuffer() { return b; }
-
- /* cons(i) is true <=> b[i] is a consonant. */
-
- private boolean cons(int i) {
- switch (b[i])
- { case 'a': case 'e': case 'i': case 'o': case 'u': return false;
- case 'y': return (i==0) ? true : !cons(i-1);
- default: return true;
- }
- }
-
- /* m() measures the number of consonant sequences between 0 and j. if c is
- a consonant sequence and v a vowel sequence, and <..> indicates arbitrary
- presence,
-
- <c><v> gives 0
- <c>vc<v> gives 1
- <c>vcvc<v> gives 2
- <c>vcvcvc<v> gives 3
- ....
- */
-
- private int m() {
- int n = 0;
- int i = 0;
- while(true)
- { if (i > j) return n;
- if (! cons(i)) break; i++;
- }
- i++;
- while(true)
- { while(true)
- { if (i > j) return n;
- if (cons(i)) break;
- i++;
- }
- i++;
- n++;
- while(true)
- { if (i > j) return n;
- if (! cons(i)) break;
- i++;
- }
- i++;
- }
- }
-
- /* vowelinstem() is true <=> 0,...j contains a vowel */
-
- private boolean vowelinstem() {
- int i; for (i = 0; i <= j; i++) if (! cons(i)) return true;
- return false;
- }
-
- /* doublec(j) is true <=> j,(j-1) contain a double consonant. */
-
- private boolean doublec(int j) {
- if (j < 1) return false;
- if (b[j] != b[j-1]) return false;
- return cons(j);
- }
-
- /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant
- and also if the second c is not w,x or y. this is used when trying to
- restore an e at the end of a short word. e.g.
-
- cav(e), lov(e), hop(e), crim(e), but
- snow, box, tray.
-
- */
-
- private boolean cvc(int i) {
- if (i < 2 || !cons(i) || cons(i-1) || !cons(i-2)) return false;
- { int ch = b[i];
- if (ch == 'w' || ch == 'x' || ch == 'y') return false;
- }
- return true;
- }
-
- private boolean ends(String s) {
- int l = s.length();
- int o = k-l+1;
- if (o < 0) return false;
- for (int i = 0; i < l; i++) if (b[o+i] != s.charAt(i)) return false;
- j = k-l;
- return true;
- }
-
- /* setto(s) sets (j+1),...k to the characters in the string s, readjusting
- k. */
-
- private void setto(String s) {
- int l = s.length();
- int o = j+1;
- for (int i = 0; i < l; i++) b[o+i] = s.charAt(i);
- k = j+l;
- }
-
- /* r(s) is used further down. */
-
- private void r(String s) { if (m() > 0) setto(s); }
-
- /* step1() gets rid of plurals and -ed or -ing. e.g.
-
- caresses -> caress
- ponies -> poni
- ties -> ti
- caress -> caress
- cats -> cat
-
- feed -> feed
- agreed -> agree
- disabled -> disable
-
- matting -> mat
- mating -> mate
- meeting -> meet
- milling -> mill
- messing -> mess
-
- meetings -> meet
-
- */
-
- private void step1() {
- if (b[k] == 's')
- {
- if (ends("sses")) k -= 2; else
- if (ends("ies")) setto("i"); else
- if (b[k-1] != 's') k--;
- }
- if (ends("eed")) { if (m() > 0) k--; } else
- if ((ends("ed") || ends("ing")) && vowelinstem())
- { k = j;
- if (ends("at")) setto("ate"); else
- if (ends("bl")) setto("ble"); else
- if (ends("iz")) setto("ize"); else
- if (doublec(k))
- { k--;
- { int ch = b[k];
- if (ch == 'l' || ch == 's' || ch == 'z') k++;
- }
- }
- else if (m() == 1 && cvc(k)) setto("e");
- }
- }
-
- /* step2() turns terminal y to i when there is another vowel in the stem. */
-
- private void step2() { if (ends("y") && vowelinstem()) b[k] = 'i'; }
-
- /* step3() maps double suffices to single ones. so -ization ( = -ize plus
- -ation) maps to -ize etc. note that the string before the suffix must give
- m() > 0. */
-
- private void step3() { if (k == 0) return; /* For Bug 1 */ switch (b[k-1]) {
- case 'a': if (ends("ational")) { r("ate"); break; }
- if (ends("tional")) { r("tion"); break; }
- break;
- case 'c': if (ends("enci")) { r("ence"); break; }
- if (ends("anci")) { r("ance"); break; }
- break;
- case 'e': if (ends("izer")) { r("ize"); break; }
- break;
- case 'l': if (ends("bli")) { r("ble"); break; }
- if (ends("alli")) { r("al"); break; }
- if (ends("entli")) { r("ent"); break; }
- if (ends("eli")) { r("e"); break; }
- if (ends("ousli")) { r("ous"); break; }
- break;
- case 'o': if (ends("ization")) { r("ize"); break; }
- if (ends("ation")) { r("ate"); break; }
- if (ends("ator")) { r("ate"); break; }
- break;
- case 's': if (ends("alism")) { r("al"); break; }
- if (ends("iveness")) { r("ive"); break; }
- if (ends("fulness")) { r("ful"); break; }
- if (ends("ousness")) { r("ous"); break; }
- break;
- case 't': if (ends("aliti")) { r("al"); break; }
- if (ends("iviti")) { r("ive"); break; }
- if (ends("biliti")) { r("ble"); break; }
- break;
- case 'g': if (ends("logi")) { r("log"); break; }
- } }
-
- /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */
-
- private void step4() { switch (b[k]) {
- case 'e': if (ends("icate")) { r("ic"); break; }
- if (ends("ative")) { r(""); break; }
- if (ends("alize")) { r("al"); break; }
- break;
- case 'i': if (ends("iciti")) { r("ic"); break; }
- break;
- case 'l': if (ends("ical")) { r("ic"); break; }
- if (ends("ful")) { r(""); break; }
- break;
- case 's': if (ends("ness")) { r(""); break; }
- break;
- } }
-
- /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */
-
- private void step5() {
- if (k == 0) return; /* for Bug 1 */ switch (b[k-1])
- { case 'a': if (ends("al")) break; return;
- case 'c': if (ends("ance")) break;
- if (ends("ence")) break; return;
- case 'e': if (ends("er")) break; return;
- case 'i': if (ends("ic")) break; return;
- case 'l': if (ends("able")) break;
- if (ends("ible")) break; return;
- case 'n': if (ends("ant")) break;
- if (ends("ement")) break;
- if (ends("ment")) break;
- /* element etc. not stripped before the m */
- if (ends("ent")) break; return;
- case 'o': if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break;
- /* j >= 0 fixes Bug 2 */
- if (ends("ou")) break; return;
- /* takes care of -ous */
- case 's': if (ends("ism")) break; return;
- case 't': if (ends("ate")) break;
- if (ends("iti")) break; return;
- case 'u': if (ends("ous")) break; return;
- case 'v': if (ends("ive")) break; return;
- case 'z': if (ends("ize")) break; return;
- default: return;
- }
- if (m() > 1) k = j;
- }
-
- /* step6() removes a final -e if m() > 1. */
-
- private void step6() {
- j = k;
- if (b[k] == 'e')
- { int a = m();
- if (a > 1 || a == 1 && !cvc(k-1)) k--;
- }
- if (b[k] == 'l' && doublec(k) && m() > 1) k--;
- }
-
- /** Stem the word placed into the Stemmer buffer through calls to add().
- * Returns true if the stemming process resulted in a word different
- * from the input. You can retrieve the result with
- * getResultLength()/getResultBuffer() or toString().
- */
- public void stem() {
- k = i - 1;
- if (k > 1) { step1(); step2(); step3(); step4(); step5(); step6(); }
- i_end = k+1; i = 0;
- }
-
- public CharSequence stem(CharSequence word) {
- b = new char[word.length()];
- char[] arr = word.toString().toCharArray();
- for(k=0;k<arr.length;k++) this.add(arr[k]);
- stem();
- return this.toString();
- }
-}
-
