I'm stuck trying to pass an array of primitives (in my case an int[]) to a method with varargs.
Let's say:
// prints: 1 2
System.out.println(String.format("%s %s", new String[] { "1", "2"}));
// fails with java.util.MissingFormatArgumentException: Format specifier '%s'
System.out.println(String.format("%s %s", new int[] { 1, 2 }));
Note however that the first line gets the following warning:
Type String[] of the last argument to method format(String, Object...) doesn't exactly match the vararg parameter type. Cast to Object[] to confirm the non-varargs invocation, or pass individual arguments of type Object for a varargs invocation.
Note also I don't input the array with a constructor, but I get it from the enclosing method, whose signature I can't change, like:
private String myFormat(int[] ints) {
// whatever format it is, it's just an example, assuming the number of ints
// is greater than the number of the format specifiers
return String.format("%s %s %s %s", ints);
}
The String.format(String format, Object... args) is waiting an Object varargs as parameter. Since int is a primitive, while Integer is a java Object, you should indeed convert your int[] to an Integer[].
To do it, you can use nedmund answer if you are on Java 7 or, with Java 8, you can one line it:
Integer[] what = Arrays.stream( data ).boxed().toArray( Integer[]::new );
or, if you don't need to have an Integer[], if an Object[] is enough for your need, you can use:
Object[] what = Arrays.stream( data ).boxed().toArray();