How do I dump the contents of a hash map?

Question

How can I dump the contents of a Java HashMap(or any other), for example to STDOUT ?

As an example, suppose that I have a complex HashMap of the following structure

Answer 1

Use HashMap.toString() (docs here):

System.out.println("HASH MAP DUMP: " + myHashMap.toString());

Generally, use Object.toString() to dump data like this.