Casting Long to Integer throws ClassCastException

Question

Im trying to cast a long into int, but failed. I am use in a Servlet in Google App Engine if that matters. I have did searches to post1 , post2 docs But no results From my logs. point to this line:

//fields
private int multiplyer;
private Map<String, Object> mappings;



//the method
        Echo.log.info("key: "+WinningSetMappingEnum.multiplyer.toString()
        +"  value: "
        +mappings.get(WinningSetMappingEnum.multiplyer.toString())
        +"  "
        +mappings.get(WinningSetMappingEnum.multiplyer.toString()).getClass().getName()
                    );//For logging

         multiplyer=(Integer)mappings.get(MappingEnum.multiplyer.toString());//PROBLEM

LOG:

com.wtsang02.deserlizeMapping: key: multiplyer value: 0 java.lang.Long
java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer

The problem was map returned Object, stated in original question but the code tag didn't show up. Solution is Object->Long->long->int — wtsang02, Jan 14 '13 at 23:39
@PaulBellora Its not dup, that is Long->Integer. See my previous comment. — wtsang02, Jan 14 '13 at 23:41

score 3 · Answer 1 · answered Jan 14 '13 at 23:12

Both Long and Integer extend java.lang.Number.

How do you want to cast one class into another that is not related directly? What you can cast are the primitive values

  Integer i = (int) (myLong.longValue())

Although it would be easier to use the intValue() method in Long.

score 0 · Accepted Answer · answered Mar 16 '13 at 16:13

0

private Map<String, Object> mappings;

returns an Object. Therefore the solution is

long l = (Long) mappings.get(WinningSetMappingEnum.multiplyer
                .toString());
        multiplyer = (int) l;

answered Mar 16 '13 at 16:13

wtsang02

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Casting Long to Integer throws ClassCastException

2 Answers2