Java文件与流测试

import java.io.File;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;
import java.io.FileWriter;  

public class titletwo {  

    public static void main(String args[]) {  

        int totalnum=0;
        String ha;
        int length;
        int n;
        char ba;
        char letter[]=new char[60];
        int sum[]=new int[60];
        int num=0;
        String chuan="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        letter=chuan.toCharArray();
         try {
             String pathname = "C:\\Users\\26624\\Desktop\\Harry Potter and the Sorcerer's Stone.txt"; // 绝对路径或相对路径都可以，这里是绝对路径，写入文件时演示相对路径
             File file = new File(pathname);
             InputStreamReader reader = new InputStreamReader(
                     new FileInputStream(file));
             BufferedReader br = new BufferedReader(reader);
             String line = "";
             line = br.readLine();
             while (line != null) {  

                 StringTokenizer str = new StringTokenizer(line, ",,., ,!,?,“,”,‘,-,'");

                 while (str.hasMoreElements()) {
                     ha=String.valueOf(str.nextElement());
                     length=ha.length();
                     n=0;
                     while(true)
                     {
                         ba=ha.charAt(n++);
                         switch(ba)
                         {
                         case 'a' : sum[0]++;break;
                         case 'b' : sum[1]++;break;
                         case 'c' : sum[2]++;break;
                         case 'd' : sum[3]++;break;
                         case 'e' : sum[4]++;break;
                         case 'f' : sum[5]++;break;
                         case 'g' : sum[6]++;break;
                         case 'h' : sum[7]++;break;
                         case 'i' : sum[8]++;break;
                         case 'j' : sum[9]++;break;
                         case 'k' : sum[10]++;break;
                         case 'l' : sum[11]++;break;
                         case 'm' : sum[12]++;break;
                         case 'n' :sum[13]++;break;
                         case 'o' :sum[14]++;break;
                         case 'p' :sum[15]++;break;
                         case 'q' :sum[16]++;break;
                         case 'r' :sum[17]++;break;
                         case 's' :sum[18]++;break;
                         case 't' :sum[19]++;break;
                         case 'u' :sum[20]++;break;
                         case 'v' :sum[21]++;break;
                         case 'w' :sum[22]++;break;
                         case 'x' :sum[23]++;break;
                         case 'y' :sum[24]++;break;
                         case 'z' :sum[25]++;break;

                         case 'A' : sum[26]++;break;
                         case 'B' : sum[27]++;break;
                         case 'C' : sum[28]++;break;
                         case 'D' : sum[29]++;break;
                         case 'E' : sum[30]++;break;
                         case 'F' : sum[31]++;break;
                         case 'G' : sum[32]++;break;
                         case 'H' : sum[33]++;break;
                         case 'I' : sum[34]++;break;
                         case 'J' : sum[35]++;break;
                         case 'K' : sum[36]++;break;
                         case 'L' : sum[37]++;break;
                         case 'M' : sum[38]++;break;
                         case 'N' :sum[39]++;break;
                         case 'O' :sum[40]++;break;
                         case 'P' :sum[41]++;break;
                         case 'Q' :sum[42]++;break;
                         case 'R' :sum[43]++;break;
                         case 'S' :sum[44]++;break;
                         case 'T' :sum[45]++;break;
                         case 'U' :sum[46]++;break;
                         case 'V' :sum[47]++;break;
                         case 'W' :sum[48]++;break;
                         case 'X' :sum[49]++;break;
                         case 'Y' :sum[50]++;break;
                         case 'Z' :sum[51]++;break;

                         }
                         totalnum++;
                         length--;
                         if(length<=0)
                         {
                             break;
                         }
                     }

                 }

                 line = br.readLine(); // 一次读入一行数据
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
         int ma,b;
         char a;
         for(int i=0;i<51;i++)
         {
             ma=sum[i];
             b=i;
             a=letter[i];
             for(int j=i+1;j<52;j++)
             {
                 if(ma>=sum[j])
                 {
                     ma=sum[j];
                     b=j;
                 }
             }
             ma=sum[i];
             sum[i]=sum[b];
             sum[b]=ma;
             letter[i]=letter[b];
             letter[b]=a;
         }
         for(int i=51;i>=0;i--)
         {
             double what=(double)sum[i]/totalnum*100;
             BigDecimal bg=new BigDecimal(what);
             double f1=bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
             System.out.println(letter[i]+"  "+f1+"%");
         }
    }

功能二、三：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;

public class titlesix {
    public static void haha(String road)
    {
        int m=0;
        int n=0;
        int flag;
        String word[]=new String[10000];
        int sum[]=new int[10000];
        String ha[]=new String[10000];
        List<String> list;
        String w;
        int totalnum=0;
        int i=0;

        try { // 防止文件建立或读取失败，用catch捕捉错误并打印，也可以throw  

            /* 读入TXT文件 */
            String pathname = road; // 绝对路径或相对路径都可以，这里是绝对路径，写入文件时演示相对路径
            File filename = new File(pathname); // 要读取以上路径的input。txt文件
            InputStreamReader reader = new InputStreamReader(
                    new FileInputStream(filename));
            BufferedReader br = new BufferedReader(reader);
            String line = "";
            line = br.readLine();
            while (line != null) {  

                StringTokenizer st2 = new StringTokenizer(line, " ,-");
                i=0;
                while (st2.hasMoreElements()) {
                    ha[i]=String.valueOf(st2.nextElement());
                    ha[i]=ha[i].toLowerCase();
                    m++;
                    list = Arrays.asList(word);
                    flag = list.indexOf(ha[i]);
                    if(flag==-1)
                    {
                        word[n]=ha[i];
                        sum[n]++;
                        n++;
                        totalnum++;
                    }
                    else
                    {
                        sum[flag]++;
                        totalnum++;
                    }
                    i++;
                }
                line = br.readLine(); // 一次读入一行数据
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        int ma=0;
        int biao=0;
        for(int j=0;j<n-1;j++)
        {
            ma=sum[j];
            biao=j;
            w=word[j];
            for(int k=j+1;k<n;k++)
            {
                if(ma<sum[k])
                {
                    ma=sum[k];
                    biao=k;
                }
            }
            sum[biao]=sum[j];
            sum[j]=ma;
            word[j]=word[biao];
            word[biao]=w;
        }
        System.out.println("请输入前N名单词的个数：");
        Scanner shuru=new Scanner(System.in);
        int mmm;
        mmm=shuru.nextInt();
        for(int j=0;j<mmm;j++)
        {
            double what=(double)sum[j]/totalnum*100;
            BigDecimal bg=new BigDecimal(what);
            double f1=bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
            System.out.println(word[j]+"  "+f1+"%");

        }
    }
    public  int way(String dao)
    {
        int length;
        int flag=1;
        Path path=Paths.get(dao);
        try
        {
            DirectoryStream<Path> children=Files.newDirectoryStream(path);
            for(Path child:children)
            {
                flag=1;
                String lujing;
                lujing=child.toString();
                length=lujing.length();
                if(length==0)
                {
                    return 0;
                }
                char sta[]=new char[1000];
                sta=lujing.toCharArray();
                for(int i=0;i<length;i++)
                {
                    if(sta[i]=='\\')
                        {
                                sta[i]='/';
                        }
                    if(sta[i]=='.')
                    {

                        flag=0;
                    }
                }
                lujing=String.valueOf(sta);
                System.out.println(lujing);
                if(flag==1)
                {
                    way(lujing);
                }
                else
                {
                    titlefive.haha(lujing);
                }
            }
        }catch(Exception e){}
        return 0;
    }
    public static void main(String[] args) {
        {
            titlesix sta=new titlesix();
            sta.way("D:/aaa");
        }
    }

}