Question

 public void insert(final String key, final String value) throws Exception {
    execute(new Command(){
      public Void execute(final Keyspace ks) throws Exception {
        ks.insert(key, createColumnPath(COLUMN_NAME), bytes(value));
        return null;
      }
    });
  }

The body of new Command() looks like an inline method?

What is this called, I want to fully understand this.

Answer 1

It’s an anonymous inner class. You’re creating a class which derives from the Command class or just implements the Command interface. In this case you’re only overriding one method, but you can override more – as well as having extra fields etc.

Java doesn’t (currently) have anything which is quite the equivalent of a C# anonymous method, if that’s what you were thinking of. An anonymous inner class is probably the closest thing to it though.