OnJava8-Examples/exceptions/Rethrowing.java

// exceptions/Rethrowing.java
// (c)2017 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.
// Demonstrating fillInStackTrace()

public class Rethrowing {
  public static void f() throws Exception {
    System.out.println(
      "originating the exception in f()");
    throw new Exception("thrown from f()");
  }
  public static void g() throws Exception {
    try {
      f();
    } catch(Exception e) {
      System.out.println(
        "Inside g(), e.printStackTrace()");
      e.printStackTrace(System.out);
      throw e;
    }
  }
  public static void h() throws Exception {
    try {
      f();
    } catch(Exception e) {
      System.out.println(
        "Inside h(), e.printStackTrace()");
      e.printStackTrace(System.out);
      throw (Exception)e.fillInStackTrace();
    }
  }
  public static void main(String[] args) {
    try {
      g();
    } catch(Exception e) {
      System.out.println("main: printStackTrace()");
      e.printStackTrace(System.out);
    }
    try {
      h();
    } catch(Exception e) {
      System.out.println("main: printStackTrace()");
      e.printStackTrace(System.out);
    }
  }
}
/* Output:
originating the exception in f()
Inside g(), e.printStackTrace()
java.lang.Exception: thrown from f()
        at Rethrowing.f(Rethrowing.java:8)
        at Rethrowing.g(Rethrowing.java:12)
        at Rethrowing.main(Rethrowing.java:32)
main: printStackTrace()
java.lang.Exception: thrown from f()
        at Rethrowing.f(Rethrowing.java:8)
        at Rethrowing.g(Rethrowing.java:12)
        at Rethrowing.main(Rethrowing.java:32)
originating the exception in f()
Inside h(), e.printStackTrace()
java.lang.Exception: thrown from f()
        at Rethrowing.f(Rethrowing.java:8)
        at Rethrowing.h(Rethrowing.java:22)
        at Rethrowing.main(Rethrowing.java:38)
main: printStackTrace()
java.lang.Exception: thrown from f()
        at Rethrowing.h(Rethrowing.java:27)
        at Rethrowing.main(Rethrowing.java:38)
*/