[SOLVED] why is this code not compiling with javac but has no errors in eclipse?

why is this code not compiling with javac but has no errors in eclipse?

the following code:

@Retention(RetentionPolicy.RUNTIME)
@Target( { ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE })
@Constraint(validatedBy = {
        MinTimeIntCoConstraintValidator.class, 
        MinTimeIntCoListConstraintValidator.class,
        MinTimeDoubleCoConstraintValidator.class, 
        MinTimeDoubleCoListConstraintValidator.class,
        })
@Documented
public @interface MinTimeValueCo
{
    int value();
    String message() default "value does not match minimum requirements";
    Class<?>[] groups() default { };
    Class<? extends Payload>[] payload() default {};
}

compiled in eclipse but fails to compile in sun/oracle compiler:

> MinTimeValueCo.java:19: illegal start of expression
>     [javac]       })
>     [javac]       ^
>     [javac] 1 error

This happened because of the comma after MinTimeDoubleCoListConstraintValidator.class,.

when I removed the comma it works fine:

@Constraint(validatedBy = {
        MinTimeIntCoConstraintValidator.class, 
        MinTimeIntCoListConstraintValidator.class,
        MinTimeDoubleCoConstraintValidator.class, 
        MinTimeDoubleCoListConstraintValidator.class
        })

I am using jdk 1.6.0.10.
Do you know why this is illegal and compiling in eclipse?

Solution

This is a bug in Java 6's javac. The JLS allows trailing commas in some places and the Eclipse compiler follows the standard here while Java 6 never allows trailing commas anywhere.

You can try to compile your code with javac from Java 7 with the options -source 6 -target 6 (to get Java 6 compatible byte code). If the bug is still there, file it. It might get fixed.