Gray Areas In Java

In case you ever wondered what weak and soft references are in Java, here are couple good articles explain what they are and when you might use them:

• Plugging memory leaks with weak references
• Plugging memory leaks with soft references

Memories of 342

Building a better HashMap is a short, but interesting, article on IBM's website about how java.util.concurrent.ConcurrentHashMap is implemented to provide much efficient concurrency than java.util.Hashtable.