How exceptions work in Java

exceptions.java

// Call some method that may throw an exception!
private void derp() throws Exception {
  somethingDangerous();
}

private void derpCaller() {
  try {
    derp();
  } catch (Exception e) {
    // do something with exception and swallow it
  }
}

private void derpCaller2() throws Exception{
  try {
    derp();
  } catch (Exception e) {
    // do something with exception BUT ALSO TRHOW IT!
    // If you throw this here the method signature must state that an exception may be thrown!
    throw e;
  }
}