public class Letter

{

 

     private char charName; //字符名

     private int times;   //字符出现的次数

     private double weight;  //字符权值

 

    public Letter() 

	{

       times = 0;

	   weight = 0;

	}

	

	public char getCharName()

	{

       return charName; 

	}

	public void setCharName(char charName)

	{

       this.charName = charName;

	}

	public int getTimes()

	{

		return times;

	}

    public void setTimes(int times)

	{

		this.times = times;

	}

	public double getWeight()

	{

		return weight;

	}

	public void setWeight(double weight)

	{

		this.weight = weight;

	}

	public double getTimesPlus()

	{

		return times++;

	}

	

}

import java.util.ArrayList;

import java.util.Iterator;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.BufferedInputStream;

import java.io.IOException;

import java.io.File;

public class LetterInformation

{

	private int n; //字符的种类

    private double sum; //字符的总数

	private ArrayList<Letter> letters; //存储字母信息

	

	public LetterInformation()

	{

		n = 0;

		sum = 0.0;

		letters = new ArrayList<Letter>();

		letters.ensureCapacity(250);

	}

	

	public void getWeight()  //获得各字符权值大小

	{

       for (int i = 0; i< letters.size() ; i++)

       {

		    int t = letters.get(i).getTimes();

			letters.get(i).setWeight(t/sum);

       }

	}



	public void readLetter(File src) //初始化letters

	{

         try(

			 BufferedInputStream fr = new BufferedInputStream(new FileInputStream(src));

			 )

        {

			if (!fr.markSupported())

			{

				System.out.println("mark/reset not supported!");

			}

			int c = fr.read();

			char ch = (char)c;

			Letter temp = new Letter(); //临时存放字符

			temp.setCharName(ch);

			letters.add(temp);          //读取文件的第一个字符

			fr.mark(1);

			fr.reset();

			n++;

			while ((c = fr.read())!= -1)

			{

			    Letter tp = new Letter();

				ch = (char)c;

				int tag = 0;

             for (int i = 0; i < letters.size(); i++) 

			  {

                if ((letters.get(i)).getCharName() == ch) 

				  {

                      letters.get(i).getTimesPlus();  //相同字符就累加1

                      sum++;

                      tag = 1;

                  }

				  if (tag == 0)                     //不同的字符就存在链表中

			      {

                      n++;

                      tp.setCharName(ch);

                      tp.getTimesPlus();

			          letters.add(temp);

                      sum++;

                  }

              }