Read file content and save to a TreeMap : TreeMap « Collections Data Structure « Java

1. Java
2. Collections Data Structure
3. TreeMap

Read file content and save to a TreeMap

 

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class LogTest {
  public static void main(String[] args) throws IOException {
    String inputfile = args[0];
    String outputfile = args[1];

    Map<String, Integer> map = new TreeMap<String, Integer>();

    Scanner scanner = new Scanner(new File(inputfile));
    while (scanner.hasNext()) {
      String word = scanner.next();
      Integer count = map.get(word);
      count = (count == null ? 1 : count + 1);
      map.put(word, count);
    }
    scanner.close();

    List<String> keys = new ArrayList<String>(map.keySet());
    Collections.sort( keys );

    PrintWriter out = new PrintWriter(new FileWriter(outputfile));
    for (String key : keys)
      out.println(key + " : " + map.get(key));
    out.close();
  }
}

   
  

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