尝试从文件中读取整数并将其存储在变量中时出现输入不匹配错误

Question

public static Matrix read(String filename) {
        
            Scanner scan = new Scanner(filename);
            int row = scan.nextInt();
            int column = scan.nextInt();
            
            Matrix mat = new Matrix(row, column);
            
            scan.nextLine();
            
            for(int i=0; i<row; i++) {
                for(int j=0; j<column; j++) {
                    mat.setElement(i, j, scan.nextInt());
                }
                scan.nextLine();
            }
            
            scan.close();
            
            return mat;
        
    }

This is currently my method to read a text file. Each text file has the matrix dimensions written at the top and then the rows of the matrix below. Ex:

2 3
1 1 1
2 2 2

When I try to store the first 2 numbers in the first row as the row and column indices, I get an input mismatch exception.

Answer 1

Probable cause of your issue

Whenever you take inputs from the user using a Scanner class. If the inputs passed doesn't match the method or an InputMisMatchException is thrown. For example, if you reading an integer data using the nextInt() method and the value passed in a String then, an exception occurs.

Handling input mismatch exception

The only way to handle this exception is to make sure that you enter proper values while passing inputs. It is suggested to specify required values with complete details while reading data from user using scanner class.