How to remove warnings java

Question

I found this and it seems to be working, I'm trying to iterate trough HashMap :

But this portion of code shows warnings and I don't have a clue how to make it not show them :

Iterator it = map.entrySet().iterator();
Map.Entry pairs = (Map.Entry) it.next();

Is there a way to "fix" this without using suppressWarnings annotation ?

Have you tried this: http://stackoverflow.com/questions/1066589/java-iterate-through-hashmap/1066607#1066607 — OscarRyz, Mar 22 '11 at 22:52
Why do you not want to use the @SuppressWarnings annotation? That's what it's there for. — It Grunt, Mar 22 '11 at 22:55
@It Grunt You joking? `@SuppressWarnings` is the last resort, surely not to be used for things you can fix so easily. — maaartinus, Mar 22 '11 at 23:01
I use it for what FindBugs in eclipse doesn't pick up.... :-) call me lazy — It Grunt, Mar 22 '11 at 23:03

score 7 · Accepted Answer · answered Mar 22 '11 at 22:47

Yes, use the correct generic definitions of it and pairs - assuming map is correctly defined.

For example:

Map<String, Integer> map = ...;
Iterator<Map.Entry<String, Integer>> it = map.entrySet().iterator();
Map.Entry<String, Integer> pairs = it.next();  // no need for cast

score 1 · Answer 2 · answered Mar 22 '11 at 22:49

1

Why not just use a for loop, as the answer with 72 upvotes suggests.

answered Mar 22 '11 at 22:49

Michael Younkin

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score 0 · Answer 3 · answered Mar 22 '11 at 22:47

0

I'm assuming the warnings you're getting, you'll want something like this I think:

Iterator<Map.Entry> it = map.entrySet().iterator();
Map.Entry pairs = it.next();

The warnings are being given because you're not specifying the type of what the Iterator is iterating over, therefore it might be an unsafe cast when you cast it to Map.Entry. Specifying the type means the compiler can ensure that things are of the expected type (in which case you don't even need to perform the cast).

answered Mar 22 '11 at 22:47

Melv

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That'll just get you a warning/cast when you try and use `pairs` – dty Mar 22 '11 at 22:49
@dty While that's true, without that code having been posted I can't really fix it and post what it should be. I'm hoping the above illustrates the concept, and then the poster can figure out how the rest of the code shoudl work. – Melv Mar 22 '11 at 22:50

score 0 · Answer 4 · answered Mar 22 '11 at 22:55

Another simple solution is to create two Arrays of Strings of the same size... one that keeps keys, the other keeps values... Keep them in the right order, and you can use a for loop to get the keys and value for any index.

Granted, it's not as fancy as getting the keys from the map and using the iterator... But it works.

score 0 · Answer 5 · answered Mar 22 '11 at 23:03

0

Firstly you should better declare your Map:

Map<String, Object> map = ...

If you declare in this way then you will be able to use map.entrySet() which return you Set with Map.Entry elements (without any warnings)

answered Mar 22 '11 at 23:03

lukastymo

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How to remove warnings java

5 Answers5