I really like this table of DP hierarchy from stackoverflow: Using a strategy pattern and a command pattern:
Then thanks to BalusC’s great summary of Examples of GoF Design Patterns in Java’s core libraries, we can read the java source code to learn DP.
Finally I’d like to advertise
GrepCode, a handy tool to locate the java source code.
P.S. GrepCode is down. Try zGrepCode!