Please follow the Java coding conventions provided by Sun, enhanced by the following conventions

• Use 2 spaces (no tabs) for indentation and 4 or more spaces if you continue, for example the condition of an if-statement, on the next line.
• Use fully qualified names for import statements:
  import java.util.Map;
  import java.util.List;
  instead of
  import java.util.*;
  

Provide useful comments for your code (Javadoc), especially for interfaces and public methods.

Exceptions: either treat (and possibly log) them or re-throw them (or a wrapper exception), but do not log in this case, as you will get untraceable logging output otherwise (same exception logged several times).