APCS/08 Hashing Sets _ Maps/03 Maps/IndexMakerMap.java

// Name: B6-24
// Date: 3/8/2020

import java.io.*;
import java.util.*;  

/* This program takes a text file, creates an index (by line numbers)
 * for all the words in the file and writes the index
 * into the output file.  The program prompts the user for the file names.
 */
public class IndexMakerMap
{
   public static void main(String[] args) throws IOException
   {
      Scanner keyboard = new Scanner(System.in);
      System.out.print("\nEnter input file name: ");
      String infileName = keyboard.nextLine().trim();
      Scanner inputFile = new Scanner(new File(infileName));
      
      DocumentIndex index = makeIndex(inputFile);
      
      //System.out.println( index.toString() );
      PrintWriter outputFile = new PrintWriter(new FileWriter("fishIndex.txt"));
      outputFile.println(index.toString());
      inputFile.close(); 						
      outputFile.close();
      System.out.println("Done.");
   }
   
   public static DocumentIndex makeIndex(Scanner inputFile)
   {
      DocumentIndex index = new DocumentIndex(); 	
      int lineNum = 0;
      while(inputFile.hasNextLine())
      {
         lineNum++;
         index.addAllWords(inputFile.nextLine(), lineNum);
      }
      return index;  
   }
}

class DocumentIndex extends TreeMap<String, TreeSet<Integer>>
{
  
  /** Extracts all the words from str, skipping punctuation and whitespace
   *  and for each word calls addWord(word, num).  A good way to skip punctuation
   *  and whitespace is to use String's split method, e.g., split("[., \"!?]") 
   */
   public void addAllWords(String str, int lineNum) 
   {
      String[] words = str.split("[., \"!?]");
      for (String word : words)
         if (!word.equals(""))
            addWord(word, lineNum);
   }

  /** Makes the word uppercase.  If the word is already in the map, updates the lineNum.
   *  Otherwise, adds word and ArrayList to the map, and updates the lineNum   
   */
   public void addWord(String word, int lineNum)
   {
      word = word.toUpperCase();
      if (containsKey(word)) {
         TreeSet<Integer> temp = get(word);
         temp.add(lineNum);
         put (word, temp);
      } else {
         TreeSet<Integer> temp = new TreeSet<>();
         temp.add(lineNum);
         put (word, temp);
      }
         
      
   }
   
   public String toString()
   {
      String out = "";
      
      for (String word : keySet()) {
         out += word + " ";
         String lineNums = get(word).toString();
         out += lineNums.substring(1, lineNums.length() - 1) + "\n";
      }
      
      return out.substring(0, out.length() - 1);
   }
}

/**********************************************
     ----jGRASP exec: java -ea IndexMakerMap
 
 Enter input file name: fish.txt
 Done.
 
  ----jGRASP: operation complete.
  
************************************************/
/****************** fishIndex.txt  **************
A 12, 14, 15
ARE 16
BLACK 6
BLUE 4, 7
CAR 14
FISH 1, 2, 3, 4, 6, 7, 8, 9, 16
HAS 11, 14
LITTLE 12, 14
LOT 15
NEW 9
OF 16
OLD 8
ONE 1, 11, 14
RED 3
SAY 15
STAR 12
THERE 16
THIS 11, 14
TWO 2
WHAT 15   
   ************************/