java - 读取 3 个文本文件并找到匹配的数字？

Question

该程序需要从 1 个文本文件中读取“信用卡”号码，将它们与第二个文本文件进行比较，如果有匹配，则将其与第三个进行比较，然后显示所有 3 个文本文件中匹配的号码。

我遇到了很多麻烦，无法弄清楚出了什么问题。任何帮助将不胜感激。

import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.FileReader;
import java.io.BufferedReader;

public class Search {

    public static void main(String[] args) throws IOException { //main method
        boolean match = false;
        String creditNumber = null;
        BufferedReader reader1 = new BufferedReader(new FileReader("creditCards1.txt"));
        creditNumber = reader1.readLine();
        while(match = false & creditNumber != null){
            System.out.println(creditNumber);
            boolean confirm = false;
            confirm = searchTwo(creditNumber);
            if(confirm == true){
                confirm = searchTwo(creditNumber);      
                System.out.println(confirm);
                break;
            }
        reader1.close();
        }


    }   

    public static boolean searchTwo(String creditNumber) throws IOException { //method for searching the 2nd text file

        boolean match = false;
        String creditNumber2 = null;
        BufferedReader reader2 = new BufferedReader(new FileReader("creditCards2.txt"));
        creditNumber2 = reader2.readLine();
        while(match = false & creditNumber != null){
            boolean confirm = false;
            confirm = searchThree(creditNumber2);
            if(confirm == true & creditNumber2.equals(creditNumber)){
                match = true;
                System.out.println(creditNumber2);
            }

            creditNumber2 = reader2.readLine();
        }
        reader2.close();
        if(match = true || creditNumber2 == null){
            return match;
        }
        return match;


    }       

public static boolean searchThree(String creditNumber) throws IOException { //method for searching the 3rd text file

        boolean match = false;
        String creditNumber3 = null;
        BufferedReader reader3 = new BufferedReader(new FileReader("creditCards3.txt"));
        creditNumber3 = reader3.readLine();

        while(match = false & creditNumber != null){

            if(creditNumber3.equals(creditNumber)){
                match = true;
                break;
            }
            creditNumber3 = reader3.readLine();     

        }
        reader3.close();
        if(match = true || creditNumber3 == null){
            return match;
        }

        return match;
    }

}

Answer 1

我发现这里有一些问题。

1. 您永远不会在 main 中设置 match = true，因此它将永远循环。

2. confirm = searchTwo(creditNumber);
   if(confirm == true){
       confirm = searchTwo(creditNumber);      
       System.out.println(confirm);
       break;
   }
   

   这段代码是多余的。

   searchTwo() 仅当 searchThree() 返回 true 时才返回 true。

3. 您没有检查 while 循环中的相等性，您只是设置变量。

   while(match = false & creditNumber != null) 
   

   应更改为:

   while(match == false && creditNumber != null)
   

4. 您需要在 while 循环内读取新行，而不仅仅是在其外部读取一次。按照目前的方式，您只能读取文件的第一行。