A HashMap can hold any object as a value, even if it is another HashMap. Eclipse is suggesting that you declare the types because that is the recommended practice for Collections. under Java 5. You are free to ignore Eclipse's suggestions.
Under Java 5, an int (or any primitive type) will be autoboxed into an Integer (or other corresponding type) when you add it to a collection. Be careful with this though, as there are some catches to using autoboxing.