@Test(dataProvider = "nextBigIntegerIntData")
public void nextBigIntegerInt(int n) {
final long seed = random.seed();
final Random random = new Random(seed);
final BigInteger value = nextBigInteger(random, BigInteger.valueOf(n));
random.setSeed(seed);
Assert.assertEquals(value.intValueExact(), random.nextInt(n));
}
/**
* Type converts values to other classes. For example an Integer can be converted to a Long.
*
* @param <T> Data Type.
* @param value The value to be converted.
* @param to The class to be converted to. Must be one of the Java types corresponding to the
* DataTypes.
* @return The converted value.
* @throws TypeMismatchException Thrown desired class is incompatible with the source class.
* @throws OverflowException Thrown only on narrowing value conversions, e.g from a BigInteger to
* an Integer.
*/
@Nullable
public static <T> T convert(Object value, Class<?> to)
throws TypeMismatchException, OverflowException {
final Object result;
if (value == null || value.getClass() == to) {
result = value;
} else {
final Class<?> from = value.getClass();
try {
if (from == Integer.class) { // Integer -> ...
if (to == Long.class) {
result = new Long(((Number) value).longValue());
} else if (to == BigInteger.class) {
result = BigInteger.valueOf(((Number) value).intValue());
} else if (to == Float.class) {
result = new Float(((Number) value).floatValue());
} else if (to == Double.class) {
result = new Double(((Number) value).doubleValue());
} else if (to == BigDecimal.class) {
// Use intValue() to avoid precision errors
result = new BigDecimal(((Number) value).intValue());
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else if (from == Long.class) { // Long -> ...
if (to == Integer.class) {
final long l = ((Long) value).longValue();
if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) {
throw new OverflowException((Number) value, to);
}
result = new Integer((int) l);
} else if (to == BigInteger.class) {
result = BigInteger.valueOf(((Number) value).longValue());
} else if (to == Float.class) {
result = new Float(((Number) value).floatValue());
} else if (to == Double.class) {
result = new Double(((Number) value).doubleValue());
} else if (to == BigDecimal.class) {
// Use longValue() to avoid precision errors
result = new BigDecimal(((Number) value).longValue());
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else if (from == BigInteger.class) { // BigInteger -> ...
final BigInteger bi = (BigInteger) value;
if (to == Integer.class) {
result = new Integer(bi.intValueExact());
} else if (to == Long.class) {
result = new Long(bi.longValueExact());
} else if (to == Float.class) {
final float f1 = bi.floatValue();
if (f1 == Float.NEGATIVE_INFINITY || f1 == Float.POSITIVE_INFINITY) {
throw new OverflowException(bi, to);
}
result = new Float(f1);
} else if (to == Double.class) {
final double d = bi.doubleValue();
if (d == Double.NEGATIVE_INFINITY || d == Double.POSITIVE_INFINITY) {
throw new OverflowException(bi, to);
}
result = new Double(d);
} else if (to == BigDecimal.class) {
result = new BigDecimal(bi);
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else if (from == Float.class) { // Float -> ...
final float fl = ((Float) value).floatValue();
if (to == Integer.class) {
if (fl < Integer.MIN_VALUE || fl > Integer.MAX_VALUE | fl % 1 > 0) {
throw new OverflowException((Number) value, to);
}
result = new Integer((int) fl);
} else if (to == Long.class) {
if (fl < Long.MIN_VALUE || fl > Long.MAX_VALUE | fl % 1 > 0) {
throw new OverflowException((Number) value, to);
}
result = new Long((long) fl);
} else if (to == BigInteger.class) {
if (fl % 1 > 0) {
throw new OverflowException((Number) value, to);
}
final BigDecimal bd = BigDecimal.valueOf(fl);
result = bd.toBigInteger();
} else if (to == Double.class) {
result = new Double(((Number) value).doubleValue());
} else if (to == BigDecimal.class) {
result = BigDecimal.valueOf(fl);
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else if (from == Double.class) { // Double -> ...
final double d = ((Double) value).doubleValue();
if (to == Integer.class) {
if (d < Integer.MIN_VALUE || d > Integer.MAX_VALUE || d % 1 > 0) {
throw new OverflowException((Number) value, to);
}
result = new Integer((int) d);
} else if (to == Long.class) { // OK
if (d < Long.MIN_VALUE || d > Long.MAX_VALUE || d % 1 > 0) {
throw new OverflowException((Number) value, to);
}
result = new Long((int) d);
} else if (to == BigInteger.class) { // OK
if (d % 1 > 0) {
throw new OverflowException((Number) value, to);
}
final BigDecimal bd = BigDecimal.valueOf(d);
result = bd.toBigInteger();
} else if (to == Float.class) { // OK
if (d < -Float.MAX_VALUE || d > Float.MAX_VALUE) {
throw new OverflowException((Number) value, to);
}
result = new Float((float) d);
} else if (to == BigDecimal.class) { // OK
result = BigDecimal.valueOf(d);
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else if (from == BigDecimal.class) { // BigDecimal -> ...
final BigDecimal bd = (BigDecimal) value;
if (to == Integer.class) { // OK
result = new Integer(bd.intValueExact());
} else if (to == Long.class) { // OK
result = new Long(bd.longValueExact());
} else if (to == BigInteger.class) { // OK
// BigDecimal modulus
final BigDecimal remainder = bd.remainder(BigDecimal.ONE);
if (!remainder.equals(BigDecimal.ZERO)) {
throw new OverflowException(bd, to);
}
result = bd.toBigInteger();
} else if (to == Float.class) { // OK
if (bd.compareTo(BigDecimal_MIN_FLOAT) < 0 || bd.compareTo(BigDecimal_MAX_FLOAT) > 0) {
throw new OverflowException(bd, to);
}
result = new Float(bd.floatValue());
} else if (to == Double.class) { // OK
if (bd.compareTo(BigDecimal_MIN_DOUBLE) < 0
|| bd.compareTo(BigDecimal_MAX_DOUBLE) > 0) {
throw new OverflowException(bd, to);
}
result = new Double(bd.doubleValue());
} else {
throw new TypeMismatchException(value.getClass(), to);
}
} else {
throw new UnexpectedException("convert: " + from.getName());
}
} catch (final ArithmeticException e) {
// Thrown by intValueExact() etc.
throw new OverflowException((Number) value, to);
}
}
@SuppressWarnings("unchecked")
final T t = (T) result;
return t;
}