Struts2 Validation for an array

Question

Question: how to validate the elements of an array?

I want to write a simple application that asks a user to enter 10 numbers using struts2.

enter.js

Answer 1

It is unlikely you are going to reuse this validator, so just use validate within the action:

import com.opensymphony.xwork2.ActionSupport;
import java.util.ArrayList;

public class NextAction extends ActionSupport{
    private Integer[] number;

    public Integer[] getNumber() {
        return number;
    }
    public void setNumber(Integer[] number) {
        this.number = number;
    }
    //Following is default behaviour so it is not worth writing
    //public String execute(){
    //    return "success";
    //}

    //add validation in action (_not tested_)
    public void validate(){
        if (number.length > 10){
          this.addActionError("Error: More than ten numbers supplied.");
        }else if (number.length < 10){
          this.addActionError("Error: Less than ten numbers supplied.");
        }
        for (int i = 0; i < number.length; i++){
           if(number[i] < 0){
             this.addActionError("Error: Number " + (i + 1) + " is less than zero.");
           }else if(number[i] > 100){
             this.addActionError("Error: Number " + (i + 1) + " is greater than 100.");
           }
        }
    }
}

Then display the field errors in the jsp with <s:actionerror /> or rewrite the above to specifically name fields (with indexes) in which case you can use , and you'll use the addFieldError method. For details on these tags see http://struts.apache.org/2.3.1.2/docs/tag-reference.html