CODEWITHSUNDEEP
javagenerics
karikari
karikari

Reputation: 6817

Got warnings from javac -Xlint:unchecked

I got 2 warnings after trying to use the -Xlint switch. How can I solve these warnings?

test:quadrantRDBTemplate mymac$ javac -Xlint:unchecked -cp mysql-connector-java-5.0.jar:iucbrf.jar *.java 
QuadrantSystemRDB.java:271: warning: [unchecked] unchecked call to put(K,V) as a member of the raw type java.util.HashMap
    argMap.put(xKey, new UniformDistribution(-1, 1));
              ^
QuadrantSystemRDB.java:272: warning: [unchecked] unchecked call to put(K,V) as a member of the raw type java.util.HashMap
    argMap.put(yKey, new UniformDistribution(-1, 1));
              ^
2 warnings

Upvotes: 5

Views: 8758

Answers (4)

selegnasol
selegnasol

Reputation: 91

Probably, that is because you need to declare a List object, say (e.g.), without omitting '<' and '>':

List<Integer> list = new ArrayList();

I tried to declare object in stack without in NetBeans, and NetBeans compiled my code with no error messages. Maybe, things are different with javac compiler.

Upvotes: 1

Suraj Chandran
Suraj Chandran

Reputation: 24801

You should use generics!! Say your xKey type is String, then declare the argMap as:

Map<String, UniformDist> argMap = new HashMap<String, UniformDist>()

Upvotes: 4

Joachim Sauer
Joachim Sauer

Reputation: 308269

A raw type is a type that could have a type argument, but hasn't got on. For example Map (and HashMap) can have type parameters K and V for the types of keys and values, respectively.

So you could specify a Map<Integer,String> to indicate that the map contains Integer objects as keys and maps them to String objects.

If you use simply Map then you don't provide that information. Raw types exist mostly for backwards compatibility and there is no reason to use them in new code.

Solution: provide the appropriate types to your Map. According to your code, the V would be UniformDistribution and K would be the type of yKey and xKey.

Upvotes: 7

Petar Minchev
Petar Minchev

Reputation: 47403

Use generics for the argMap. I suppose the QuadrantSystemRDB is from your code. If it is not you can hardly do anything:)

Upvotes: 1

Related Questions