Java 用hashmap统计词频

1,a,28
2,b,35
3,c,28
4,d,35
5,e,28
6,a,28
7,b,35
8,c,28
9,a,28

案例

public class FileTest {

  static File filea = new File("C:\\Temp\\1\\a.txt");

  static HashMap<String, Integer> hashmap = new HashMap<String, Integer>();

  public static void main(String[] args) throws IOException {
    BufferedReader bra = new BufferedReader(new FileReader(filea));
    Scanner sa = new Scanner(bra);

    while (sa.hasNextLine()) {
      String line = sa.nextLine();
      String name = line.split(",")[1];
      if (hashmap.containsKey(name)) 
        hashmap.put(name,hashmap.get(name) + 1)
      else
        hashmap.put(name, 1);
    }
    for (Entry<String, Integer> entry : hashmap.entrySet()) {
      Object key = entry.getKey();
      Object val = entry.getValue();

      System.out.println(key.toString() + " " + val.toString());
    }
  }
}

d 1
e 1
b 2
c 2
a 3