java - 通过文件写入器打印所有值

Question

我想打印用户将输入的所有字母，但问题是，我的程序仅打印用户将输入的最后一个值，并且仅将最后一个值记录在 Ascii.txt。它应该看起来像这样

例如:用户输入A,B,c,C

我也想删除逗号，但我不能:(

“Ascii.txt”中的输出应该是:

A = 65
B = 66
c = 99
C = 67

请不要笑我，因为我还是一名学生，而且是编程新手，非常感谢

import java.io.*;

public class NewClass2{
  public static void main(String args[]) throws IOException{



  BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));

  System.out.println("Please Enter  letters separated by comma: ");

  String str = buff.readLine();
  for ( int i = 0; i < str.length(); ++i )
  {
    char c = str.charAt(i);
    int j = (int) c;
    System.out.println(c +" = " + j);
    {
      try
      {
         FileWriter fstream = new FileWriter("Ascii.txt");
         BufferedWriter out = new BufferedWriter(fstream);

         out.write(c+"  =  "+j);
         out.close();

       }catch (Exception e){
       }
     }
    }
  }
  }

Answer 1

问题是您要关闭并重新打开要转储到 ASCII 文件的每个字符的 FileStream。因此，在写入字符之前您的文件将被清空。只需将流的创建和关闭移到循环之外即可。

    BufferedReader buff = new BufferedReader(new  InputStreamReader(System.in));
    System.out.println("Please Enter  letters separated by comma: ");

    String str = buff.readLine();
    BufferedWriter out = null;
    try
    {
        FileWriter fstream = new FileWriter("Ascii.txt");
        out = new BufferedWriter(fstream);
        for ( int i = 0; i < str.length(); ++i )
        {
            char c = str.charAt(i);
            int j = c;
            System.out.println(c + " = " + j);

            out.write(c + "  =  " + j);

        }
    }

    catch ( Exception e )
    {
        ;
    }
    finally
    {
        if ( out != null )
        {
            out.close();
        }
    }

为了从输出中删除逗号，我建议使用 String.split() :

    //...          
    String[] splittedStr = str.split(",");
    for ( int i = 0; i < splittedStr.length; i++ )
    {
        if ( splittedStr[i].length() > 0 )
        {
            char c = splittedStr[i].charAt(0);
            int j = c;

            out.write(c + "  =  " + j);
        }
    }
    //...