chained exception

[mu gaandimara]

What is chained exception ???

[Sebastian Janisch]

When you wrap an exception that is the root cause in another exception.

The Servlet Spec makes use of it.

the doGet, doPost etc. methods of HttpServlet throw a ServletException.

Imagine code like this.

  try {
    ResultSet rSet = /*some sql magic*/;
} catch (SQLException e) {
    throw new ServletException(e.getMessage (), e);
} 

You chain the SQLException together with the ServletException since you cannot throw it yourself (the signature does not allow this)

ServletException itself has a method called getRootCause() that returns the Exception you chained.

[Rob Spoor]

Moving to Beginning Java.

[mu gaandimara]

Can we wrap a Checked Exception in a RuntimeException ??

[Rob Spoor]

Sure. If the class does not have a constructor that has a Throwable parameter for the cause, you can always set the cause later:

throw new RuntimeException(e);
// similar:
RuntimeException e2 = new RuntimeException(e.getMessage());
e2.initCause(e);
throw e2;

And please read your private messages regarding an important announcement.

Thank you,

Rob

[mu gaandimara]

thank you

[Maneesh Godbole]

mu gaandimara wrote:

Please check your private messages for an important administrative matter.