OnJava8-Examples/exceptions/ExtraFeatures.java

// exceptions/ExtraFeatures.java
// (c)2020 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Further embellishment of exception classes

class MyException2 extends Exception {
  private int x;
  MyException2() {}
  MyException2(String msg) { super(msg); }
  MyException2(String msg, int x) {
    super(msg);
    this.x = x;
  }
  public int val() { return x; }
  @Override
  public String getMessage() {
    return "Detail Message: "+ x
      + " "+ super.getMessage();
  }
}

public class ExtraFeatures {
  public static void f() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from f()");
    throw new MyException2();
  }
  public static void g() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from g()");
    throw new MyException2("Originated in g()");
  }
  public static void h() throws MyException2 {
    System.out.println(
      "Throwing MyException2 from h()");
    throw new MyException2("Originated in h()", 47);
  }
  public static void main(String[] args) {
    try {
      f();
    } catch(MyException2 e) {
      e.printStackTrace(System.out);
    }
    try {
      g();
    } catch(MyException2 e) {
      e.printStackTrace(System.out);
    }
    try {
      h();
    } catch(MyException2 e) {
      e.printStackTrace(System.out);
      System.out.println("e.val() = " + e.val());
    }
  }
}
/* Output:
Throwing MyException2 from f()
MyException2: Detail Message: 0 null
        at ExtraFeatures.f(ExtraFeatures.java:24)
        at ExtraFeatures.main(ExtraFeatures.java:38)
Throwing MyException2 from g()
MyException2: Detail Message: 0 Originated in g()
        at ExtraFeatures.g(ExtraFeatures.java:29)
        at ExtraFeatures.main(ExtraFeatures.java:43)
Throwing MyException2 from h()
MyException2: Detail Message: 47 Originated in h()
        at ExtraFeatures.h(ExtraFeatures.java:34)
        at ExtraFeatures.main(ExtraFeatures.java:48)
e.val() = 47
*/