java.lang.NumberFormatException用于将字符串转换为Java

Question

I have been searching for an answer to this, and I haven't been able to find someone who has rectified this quite yet. I'm trying to populate an array, but check if it gets larger than a certain value. However, when I run this, I get a Exception in thread "main" java.lang.NumberFormatException: For input string: "" Error. Here is the code for it:

    public void setReadData() throws NoSuchElementException {
    try {

        for (int i = 0; i < getRows(); i++) {
            String numbers = p.nextLine();
            String[] inputs = numbers.split(" ");
            if (inputs.length > getCols()) {
                System.out.println("There are more columns than the size specified!\n");
                System.exit(1);
            }
            for (int j = 0; j < getCols(); j++) {
                int data = Integer.parseInt(inputs[j]);
                this.setData(i,j,data);
            }
        }

And the error code is:

Exception in thread "main" java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:504)
at java.lang.Integer.parseInt(Integer.java:527)
at foo.Bar.setReadData(Matrix.java:49)
at foo.Bar.main(Matrix.java:226)

Any help is very much appreciated!

----EDIT----

To clarify, the old code that worked was:

for (int i = 0; i < getRows(); i++) {
            p.nextLine();
            for (int j = 0; j < getCols(); j++) {
                this.setData(i,j,p.nextInt()); 
            }

        }

However, there is no checking that the whole line has been checked.

Answer 1

Try this:

for (int j = 0; j < getCols(); j++) {
    if(!inputs[j].equals("")){
        int data = Integer.parseInt(inputs[j]);
        this.setData(i,j,data);
    }
}

Answer 2

java.lang.NumberFormatException:

This exception invoke when you try to convert invalid string to integer or by passing null value to parseInt() method.

1. Invalid conversion

 int var=Integer.parseInt("a");//throw NumberFormatException 

1. Empty string

int var=Integer.parseInt("");//throw NumberFormatException

Answer 3

If the line inputted contained two consecutive space characters, splitting on a space character would result in one if the elements being a blank, which would explain your error.

To treat multiple spaces as one separator, do this:

String[] inputs = numbers.split(" +");

Adding the plus sign to the split regex will consume any extra spaces between numbers.

Answer 4

So I ended up finding the answer. I needed to add a p.nextline() above the for loop to get it to properly read the next line of code. Thanks for all the help to everyone. Your answers were greatly appreciated.

Apparently, what nextline does is it grabs the remainder of the current line, outputs that to whatever (if anything) you have it equal to, and move the pointer to the next line. That's why I was having issues.