swing - Java - how can I check what is exactly entered into a JOptionPane.showInputDialog -

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this code

import java.util.random;  import javax.swing.joptionpane; public class randomnumbersv2 {      public static void main(string[] args){         double randomnumber = double.parsedouble(joptionpane.showinputdialog("please enter maximum number program generate"));          random rnd = new random();         system.out.println(rnd.nextint(how make sure eneted in joption can put here)); // change int whatever number want, number max random number generated          joptionpane.showmessagedialog(null, "your random number is" + randomnumber);      }  }

random#nextint accepts integer value upper bound. therefore value entered should such. also, per docs, number should positive:

try {    int maxnumber =             integer.parseint(joptionpane.showinputdialog("please enter input"));     if (maxnumber > 0) {      random rnd = new random();      system.out.println(rnd.nextint(maxnumber));    } else {      throw new illegalargumentexception("non positive number not allowed");    } } catch (numberformatexception e) {    throw new illegalargumentexception("invalid integer", e); }

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