import java.io.BufferedReader;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.IOException;import java.text.NumberFormat;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.List;import java.util.Map;import java.util.Map.Entry;import java.util.Scanner;import java.util.TreeMap;public class Flutter {    private static Map
     
       myTreeMap = null;    private static List
      
       
        > list = null;    public static void main(String[] args) {                int n = 0;        Scanner in = new Scanner(System.in);        String filename = "E:\\Homework\\大二下\\软工\\飘英文版.txt";         do        {            System.out.println("1.显示单词并排序 2.显示字母频率 3.指定显示前n个英文单词 4.停用词 0.退出");            n = in.nextInt();            switch(n)            {            case 2:frequency();break;            case 1:                readAndSave(filename);                sort();                for(Map.Entry
        
          map : list) {                    if((!map.getKey().equals("the"))||(!map.getKey().equals("a")))                        System.out.println(map.getKey() + " :\t" + map.getValue());                }              //System.out.println("耗时：" + (System.currentTimeMillis() - t1) + "ms");break;                break;            case 3:                {                    System.out.println("输入数字");                    int num = in.nextInt();                    int c = 0;                    readAndSave(filename);                    sort();                    for(Map.Entry
         
           map : list) {                        if((!map.getKey().equals("the"))||(!map.getKey().equals("a")))                            System.out.println(map.getKey() + " :\t" + map.getValue());                        c++;                        if(c >= num)                            break;                    }                    break;                }            case 4:                {                    readAndSave(filename);                    sort();                    stop();                    for(Map.Entry
          
            map : list) { if((!map.getKey().equals("the"))||(!map.getKey().equals("a"))) System.out.println(map.getKey() + " :\t" + map.getValue()); } break; } } }while(n!=0); } public static void readAndSave(String filename) { //long t1 = System.currentTimeMillis(); String s; BufferedReader br = null; try { br = new BufferedReader(new FileReader(filename)); StringBuffer sb = new StringBuffer(); //将文件内容存入StringBuffer中 while((s = br.readLine()) != null) { sb.append(s); } //不区分大小写 String str = sb.toString().toLowerCase(); //分隔字符串并存入数组 (以，。空格分割) String[] elements = str.split("[,.“” ‘’?\\s]"); int count = 0; myTreeMap = new TreeMap
           
            (); //遍历数组将其存入Map
            
             中 for(int i = 0; i < elements.length; i++) { if(myTreeMap.containsKey(elements[i])) { count = myTreeMap.get(elements[i]); myTreeMap.put(elements[i], count + 1); } else { myTreeMap.put(elements[i], 1); } } //直接遍历Map输出 /*for(Map.Entry
             
               entry:myTreeMap.entrySet()){ System.out.println(entry.getKey()+" :\t"+entry.getValue()); }*/ //对频率从大到小排序，然后输出 }catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }finally { try { br.close(); }catch(Exception e) { e.printStackTrace(); } } } public static void sort() { //将map.entrySet()转换成list list = new ArrayList
              
               
                >(myTreeMap.entrySet()); //通过比较器实现排序 Collections.sort(list, new Comparator
                
                 
                  >() { //降序排序 public int compare(Entry
                  
                    o1, Entry
                   
                     o2) { return o2.getValue().compareTo(o1.getValue()); // return o1.getValue().compareTo(o2.getValue()); //升序排序 } }); } private static String formattedDecimalToPercentage(double decimal) { //获取格式化对象 NumberFormat nt = NumberFormat.getPercentInstance(); //设置百分数精确度2即保留两位小数 nt.setMinimumFractionDigits(2); return nt.format(decimal); } public static void frequency() { String a1; char a='A'; int a2[]=new int[27]; char b1[]=new char[26]; char b2[]=new char[26]; for(int i=0;i<26;i++) { b1[i]=a; b2[i]=(char)(a+32); a++; } /*for(int i=0;i<26;i++) { System.out.println(b1[i]); System.out.println(b2[i]); }*/ try { BufferedReader in = new BufferedReader(new FileReader("E:\\\\Homework\\\\大二下\\\\软工\\\\飘英文版.txt")); String str; while ((str = in.readLine()) != null) { // System.out.println(str); char[] d=str.toCharArray(); for(int i=0;i
                    
                      stopword = new ArrayList(); while ((str = br_stop.readLine()) != null) { //使用readLine方法，一次读一行 读取停用词 stopword.add(str); } br_stop.close(); myTreeMap.remove(stopword); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }}