Data commit

Task/Inverted-index/Java/inverted-index-1.java

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+package org.rosettacode;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class InvertedIndex {
+
+    List<String> stopwords = Arrays.asList("a", "able", "about",
+            "across", "after", "all", "almost", "also", "am", "among", "an",
+            "and", "any", "are", "as", "at", "be", "because", "been", "but",
+            "by", "can", "cannot", "could", "dear", "did", "do", "does",
+            "either", "else", "ever", "every", "for", "from", "get", "got",
+            "had", "has", "have", "he", "her", "hers", "him", "his", "how",
+            "however", "i", "if", "in", "into", "is", "it", "its", "just",
+            "least", "let", "like", "likely", "may", "me", "might", "most",
+            "must", "my", "neither", "no", "nor", "not", "of", "off", "often",
+            "on", "only", "or", "other", "our", "own", "rather", "said", "say",
+            "says", "she", "should", "since", "so", "some", "than", "that",
+            "the", "their", "them", "then", "there", "these", "they", "this",
+            "tis", "to", "too", "twas", "us", "wants", "was", "we", "were",
+            "what", "when", "where", "which", "while", "who", "whom", "why",
+            "will", "with", "would", "yet", "you", "your");
+
+    Map<String, List<Tuple>> index = new HashMap<String, List<Tuple>>();
+    List<String> files = new ArrayList<String>();
+
+    public void indexFile(File file) throws IOException {
+        int fileno = files.indexOf(file.getPath());
+        if (fileno == -1) {
+            files.add(file.getPath());
+            fileno = files.size() - 1;
+        }
+
+        int pos = 0;
+        BufferedReader reader = new BufferedReader(new FileReader(file));
+        for (String line = reader.readLine(); line != null; line = reader
+                .readLine()) {
+            for (String _word : line.split("\\W+")) {
+                String word = _word.toLowerCase();
+                pos++;
+                if (stopwords.contains(word))
+                    continue;
+                List<Tuple> idx = index.get(word);
+                if (idx == null) {
+                    idx = new LinkedList<Tuple>();
+                    index.put(word, idx);
+                }
+                idx.add(new Tuple(fileno, pos));
+            }
+        }
+        System.out.println("indexed " + file.getPath() + " " + pos + " words");
+    }
+
+    public void search(List<String> words) {
+        for (String _word : words) {
+            Set<String> answer = new HashSet<String>();
+            String word = _word.toLowerCase();
+            List<Tuple> idx = index.get(word);
+            if (idx != null) {
+                for (Tuple t : idx) {
+                    answer.add(files.get(t.fileno));
+                }
+            }
+            System.out.print(word);
+            for (String f : answer) {
+                System.out.print(" " + f);
+            }
+            System.out.println("");
+        }
+    }
+
+    public static void main(String[] args) {
+        try {
+            InvertedIndex idx = new InvertedIndex();
+            for (int i = 1; i < args.length; i++) {
+                idx.indexFile(new File(args[i]));
+            }
+            idx.search(Arrays.asList(args[0].split(",")));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    private class Tuple {
+        private int fileno;
+        private int position;
+
+        public Tuple(int fileno, int position) {
+            this.fileno = fileno;
+            this.position = position;
+        }
+    }
+}