Question

I have textfield array which has to accept only numeric values i.e. 1-5.

<s:textfield name="marks[0]" maxlength="1" /> 
<s:textfield name="marks[1]" maxlength="1" /> 
<s:textfield name="marks[2]" maxlength="1" />  and so on upto 9 textfields.

I have getter/setter methods for this as follows

public List<Integer> getMarks(){
     return marks;
}
public void setMarks(List<Integer> marks){
     this.marks = marks;
}

How to ensure that user does not enter non numeric values like alphabets? If I enter character it throws runtime exception ‘java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer ‘ pointing to validate method in the Next JSp page.

public void validate(){
  for(i=0;i<9;i++){
     if (marks.get(i)>5)     //this line throws above ClassCastException
    addFieldError("...");
  }
}

How to solve this exception as well as validation to continue? In other Pages where single textfield is there, invalid.fieldvalue.error is displayed but for List I am getting above exception

Answer 1

Just put your validation logic inside try catch block

public void validate(){
  try{
    for(i=0;i<9;i++){
      if (marks.get(i)>5)     //this line throws above ClassCastException
        addFieldError("...");
    }
  }catch(Exception e){
  }
}