Thread: java-Exception

Hi there,

Anyone knows how to solve this error, it only happens when I leave the user input field blank.

java.lang.NumberFormatException: For input string: ""
java.lang.NumberFormatException.forInputString(Num berFormatException.java:48)
java.lang.Integer.parseInt(Integer.java:470)
java.lang.Integer.parseInt(Integer.java:499)

thanks for the link, but my error is till not solve. After reading, "NumberFormatException - if the string does not contain a parsable integer." because the user input is left blank.

Any more suggestions how to solve it? thanks

Look over the code you failed to provide. Decide where in the code you have tried to pull an integer value from an empty string. Figure out a way to prevent the string from not containing an integer before the error occurs.

Exactly. Is an empty string a parsable integer? No. Validate user input if you expect an integer, or catch the exception.

And please, when posting code, wrap it in the code tags. The forum rules clearly explains how to do this.

Thanks copeg, Can you give an example? as try to solve it by:

if(studentid != null && !studentid.equals("")){
int studentIdNum = Integer.parseInt(studentid);
}
else{
//no number, deal with it
throw new Exception("Invalid student Id!");
}

it doesn't work. thanks

Please define, "it doesn't work" (to be blunt: that's about as much information to us as us saying to you "then fix it")

I still get the following error when the user input field is left blank:

java.lang.NumberFormatException: For input string: ""
java.lang.NumberFormatException.forInputString(Num berFormatException.java:48)
java.lang.Integer.parseInt(Integer.java:470)
java.lang.Integer.parseInt(Integer.java:499)

Is there anything wrong in my if statement?

if(studentid != null && !studentid.equals("")){
int studentIdNum = Integer.parseInt(studentid);
}
else{
//no number, deal with it
throw new Exception("Invalid student Id!");
}

thanks