Re: Where shoul I throw RuntimeException

Tom Anderson <>
Wed, 20 May 2009 23:34:34 +0100
On Tue, 19 May 2009, dimka wrote:

I want to know, where can I use runtime exceptions?
For example, I have method like this:
public String getNameById(long id) {
 Connection connection = null;
 Statement st = null;
 try {
   connection = getConnection();
   st = connection.createStatement();
   ResultSet rs = st.executeQuery("SELECT NAME WHERE id=" + id);
   if (! {
     //--->Here, I can return null, throw RuntimeException, throw
catched exception<---
   return rs.getString(1);
 } catch (SQLException e) {
   //--->Here, I can return null, throw RuntimeException, throw
catched exception<---
 } finally {
     closeConnectionAndStatement(st, connection);

In this example, I can return null and describe this in javadoc for
method. But, when other developer use this method, he cann't get id
from somewhere, he must know that object with this id exist...
Ever, when I should make a choice, I cann't choose right answer :(
What do you think about this?

I think that method should throw SQLException.

It definitely should not return null - that's almost never a good idea. It
shouldn't throw a RuntimeException, because that won't force the callers
to face up to the possiblity of failure. It could throw another checked
exception, perhaps a domain-specific one like DimkaDataLayerException,
rather an an SQLException. But what is certain - although others, who
labour in ignorance or sin, may disagree - is that it should throw a
checked exception. If there is a real possibility of failure, callers
should be made aware of it, and be made to prepare for it.


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