Example:
* public interface PolarCoordinate extends Storable {
* double getTheta();
* @FloatConstraint(min=0, max=Math.PI * 2, disallowed=Double.NaN)
* void setTheta(double radians);
*
* ...
* }
*
*
* @author Brian S O'Neill
* @see IntegerConstraint
* @see TextConstraint
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@ConstraintDefinition
public @interface FloatConstraint {
/**
* Specific allowed values for property. Default is unlimited.
*/
double[] allowed() default {};
/**
* Specific disallowed values for property. Default is none.
*/
double[] disallowed() default {};
/**
* Specify minimum allowed value for float/double property. Default is unlimited.
*/
double min() default Double.NEGATIVE_INFINITY;
/**
* Specify maximum allowed value for float/double property. Default is unlimited.
*/
double max() default Double.POSITIVE_INFINITY;
/**
* Constraint implementation for {@link FloatConstraint}.
*/
public static class Constraint {
private final String mPropertyName;
private final double mMinValue;
private final double mMaxValue;
/** Disallowed values, sorted for binary search. */
private final double[] mDisallowed;
/** Allowed values, sorted for binary search. */
private final double[] mAllowed;
/**
* @param type type of object that contains the constrained property
* @param propertyName name of property with constraint
* @param ann specific annotation that binds to this constraint class
*/
public Constraint(Class type, String propertyName, FloatConstraint ann) {
this(type, propertyName,
ann.min(), ann.max(), ann.allowed(), ann.disallowed());
}
/**
* @param type type of object that contains the constrained property
* @param propertyName name of property with constraint
* @param min minimum allowed value
* @param max maximum allowed value
* @param allowed optional set of allowed values
* @param disallowed optional set of disallowed values
*/
public Constraint(Class type, String propertyName,
double min, double max, double[] allowed, double[] disallowed) {
mPropertyName = propertyName;
mMinValue = min;
mMaxValue = max;
if (mMaxValue < mMinValue) {
throw new MalformedTypeException
(type, "Illegal range for float constraint on property \"" +
propertyName + "\": " + rangeString());
}
if (disallowed == null || disallowed.length == 0) {
disallowed = null;
} else {
disallowed = disallowed.clone();
Arrays.sort(disallowed);
}
if (allowed == null || allowed.length == 0) {
allowed = null;
} else {
allowed = allowed.clone();
Arrays.sort(allowed);
for (double value : allowed) {
if (value < mMinValue || value > mMaxValue ||
(disallowed != null && Arrays.binarySearch(disallowed, value) >= 0)) {
throw new MalformedTypeException
(type, "Allowed value contradiction for float constraint " +
"on property \"" + propertyName + "\": " + value);
}
}
// No need to have a set of disallowed values.
disallowed = null;
}
mDisallowed = disallowed;
mAllowed = allowed;
}
public void constrain(double propertyValue) {
if (propertyValue < mMinValue || propertyValue > mMaxValue) {
throw new IllegalArgumentException
("Value for \"" + mPropertyName + "\" must be in range " +
rangeString() + ": " + propertyValue);
}
if (mDisallowed != null && Arrays.binarySearch(mDisallowed, propertyValue) >= 0) {
throw new IllegalArgumentException
("Value for \"" + mPropertyName + "\" is disallowed: " + propertyValue);
}
if (mAllowed != null && Arrays.binarySearch(mAllowed, propertyValue) < 0) {
throw new IllegalArgumentException
("Value for \"" + mPropertyName + "\" is not allowed: " + propertyValue);
}
}
public void constrain(CharSequence propertyValue) {
if (propertyValue != null) {
try {
constrain(Double.parseDouble(propertyValue.toString()));
} catch (NumberFormatException e) {
throw new IllegalArgumentException
("Value for \"" + mPropertyName + "\" is not a number: " +
propertyValue);
}
}
}
public void constrain(char propertyValue) {
if ('0' <= propertyValue && propertyValue <= '9') {
constrain((double) (propertyValue - '0'));
} else {
throw new IllegalArgumentException
("Value for \"" + mPropertyName + "\" is not a number: " + propertyValue);
}
}
public void constrain(char[] propertyValue) {
if (propertyValue != null) {
constrain(new String(propertyValue));
}
}
private String rangeString() {
StringBuilder b = new StringBuilder();
b.append('(');
if (mMinValue > Double.MIN_VALUE) {
b.append(mMinValue);
}
b.append("..");
if (mMaxValue < Double.MAX_VALUE) {
b.append(mMaxValue);
}
b.append(')');
return b.toString();
}
}
}