Bad attempt to compute absolute value of signed 32-bit random integer

RV: Bad attempt to compute absolute value of signed 32-bit random integer (RV_ABSOLUTE_VALUE_OF_RANDOM_INT)

This code generates a random signed integer and then computes the absolute value of that random integer. If the number returned by the random number generator is Integer.MIN_VALUE, then the result will be negative as well (since Math.abs(Integer.MIN_VALUE) == Integer.MIN_VALUE).

from :http://findbugs.sourceforge.net/bugDescriptions.html#RV_ABSOLUTE_VALUE_OF_RANDOM_INT    

解决办法：

• cast the random number to long before calling Math.abs

• use random.nextInt(Integer.MAX_VALUE) to get a number from 0 to MAX_VALUE - 1