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float i = Float.MIN_VALUE;
float j = Float.MAX_VALUE;
if ((i < Short.MIN_VALUE) || (i > Short.MAX_VALUE) ||
    (j < Short.MIN_VALUE) || (j > Short.MAX_VALUE)) {
  throw new ArithmeticException ("Value is out of range");    
}

short b = (short) i;
short c = (short) j;
//other operations

Noncompliant Code Example (double Conversion to float)

The narrowing primitive conversions in this noncompliant code example suffer from loss in the magnitude of the numeric value, as well as a loss of precision. Becuase Double.MAX_VALUE is larger than Float.MAX_VALUE, c receives the value infinity. And because Double.MIN_VALUE is smaller than Float.MIN_VALUE, d receives the value 0.

double i = Double.MIN_VALUE;
double j = Double.MAX_VALUE;
float b = (float) i;
float c = (float) j;

Compliant Solution (double Conversion to float)

Perform range checks on both i and j variables before proceeding with the conversions.

double i = Double.MIN_VALUE;
double j = Double.MAX_VALUE;
if ((i < Float.MIN_VALUE) || (i > Float.MAX_VALUE) ||
    (j < Float.MIN_VALUE) || (j > Float.MAX_VALUE)) {
  throw new ArithmeticException ("Value is out of range");    
}

float b = (float) i;
float c = (float) j;
//other operations

Exceptions

EXP13-EX1: Since Java's narrowing conventions are well-defined, they may be intentinally applied by programmers, and so their outputs would be expected and perfectly reasonable. Code that accounts for potential truncation, and documents this, is concisered a valid exception to this rule.

Risk Assessment

Casting a numeric value to a narrower type can result in information loss related to the sign and magnitude of the numeric value. Consequently, data can be misrepresented or interpreted incorrectly.

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