public interface DbErrcall
{
public abstract void errcall(String errpfx, String msg);
}
public class Db
{
public void set_errcall(DbErrcall errcall);
...
}
Description
When an error occurs in the Berkeley DB library, an exception is thrown. In
some cases, however, the errno value may be insufficient to
completely describe the cause of the error, especially during initial
application debugging.
The Db.set_errcall method is used to enhance the mechanism for reporting error
messages to the application. The DbEnv.set_errcall method must be
called with a single object argument. The object's class must implement
the DbErrcall interface. In some cases, when an error occurs, Berkeley DB will
invoke the object's errcall() method with two arguments; the first is the
prefix string (as previously set by Db.set_errpfx or
DbEnv.set_errpfx), the second will be an error message string.
It is up to this method to display the message in an appropriate manner.
Alternatively, you can use the DbEnv.set_error_stream method to display
the additional information via an output stream. You should not mix these
approaches.
This error logging enhancement does not slow performance or significantly
increase application size, and may be run during normal operation as well
as during application debugging.
For Db handles opened inside of Berkeley DB environments, calling the
Db.set_errcall method affects the entire environment and is equivalent to calling
the DbEnv.set_errcall method.
The Db.set_errcall interface may be used to configure Berkeley DB at any time
during the life of the application.