Throwing an Exception from a Method : Exception « Development « Java Tutorial

1. Java Tutorial
2. Development
3. Exception

1. Most of the time a try block is accompanied by a catch block that catches the java.lang.Exception in addition to other catch blocks.
2. The order of the catch blocks is important.
3. The more specific exception type appears first.

public class MainClass {

  public static void main(String[] args) {
    String input = null;
    try {
      String capitalized = capitalize(input);
      System.out.println(capitalized);
    } catch (NullPointerException e) {
      System.out.println(e.toString());
    }
  }

  public static String capitalize(String s) throws NullPointerException {
    if (s == null) {
      throw new NullPointerException("Your passed a null argument");
    }
    Character firstChar = s.charAt(0);
    String theRest = s.substring(1);
    return firstChar.toString().toUpperCase() + theRest;
  }
}