do I need "volatile" for HashMap? when I apply ReentrantReadWriteLock on it.

fomr javaoc of ReentrantReadWriteLock
an example:
class CachedData {
Object data;
volatile boolean cacheValid;
ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();

void processCachedData() {
rwl.readLock().lock();
if (!cacheValid) {
.....
use(data);
rwl.readLock().unlock();
}
}
Using volatile here makes sense to me.

but if in my class looks like this,
class CachedData {
HashMap<Key, Obj> data; // <---- here
ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();

void processCachedData(Key k) {
rwl.readLock().lock();
if (!data.containsKey(k)) { // <--- here
.....
use(data);
rwl.readLock().unlock();
}
}

should I declare as
"volatile HashMap"

or for which "variable" type should I apply volatile in such
situation?

thanks.

.