作业

package pinlv;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Pinlv {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new FileReader("D:\wenzhang.txt"));
        StringBuffer buffer = new StringBuffer();
        String line = null;
        while ((line = reader.readLine()) != null) {
            buffer.append(line);
        }
        reader.close();
        Pattern expression = Pattern.compile("[a-zA-Z]+");
        String string = buffer.toString();
        Matcher matcher = expression.matcher(string);//
        Map<String, Integer> map = new TreeMap<String, Integer>();
        String word = "";
        int times = 0;
        while (matcher.find()) {
            word = matcher.group();
            if (map.containsKey(word)) {
                times = map.get(word);
                map.put(word, times + 1);
            } else {
                map.put(word, 1);
            }
        }
        List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(map.entrySet());
        Comparator<Map.Entry<String, Integer>> comparator = new Comparator<Map.Entry<String, Integer>>() {
            public int compare(Map.Entry<String, Integer> left,
                    Map.Entry<String, Integer> right) {
                return (left.getValue()).compareTo(right.getValue());
            }
        };
        Collections.sort(list, comparator);
        int last = list.size() - 1;
        for (int i = last; i > last - 6; i--) {
            String key = list.get(i).getKey();
            Integer value = list.get(i).getValue();
            System.out.println(key + " :" + value);
        }
    }
}

在上机的前半个多小时里，我终于弄明白了怎么读取txt文件，在接下来的编程中使我的效率大大地提高，然后就是主要卡在了不知该怎么比较单词出现的频率