Note: never used for a BigInteger with a magnitude of zero. + * + * @see #firstNonzeroIntNum() */ - @Deprecated - private int firstNonzeroIntNum; + private int firstNonzeroIntNumPlusTwo; /** * This mask is used to obtain the value of an int as if it were unsigned. @@ -3240,7 +3226,7 @@ * @return index of the rightmost one bit in this BigInteger. */ public int getLowestSetBit() { - @SuppressWarnings("deprecation") int lsb = lowestSetBit - 2; + int lsb = lowestSetBitPlusTwo - 2; if (lsb == -2) { // lowestSetBit not initialized yet lsb = 0; if (signum == 0) { @@ -3252,7 +3238,7 @@ ; lsb += (i << 5) + Integer.numberOfTrailingZeros(b); } - lowestSetBit = lsb + 2; + lowestSetBitPlusTwo = lsb + 2; } return lsb; } @@ -3271,7 +3257,7 @@ * representation of this BigInteger, excluding a sign bit. */ public int bitLength() { - @SuppressWarnings("deprecation") int n = bitLength - 1; + int n = bitLengthPlusOne - 1; if (n == -1) { // bitLength not initialized yet int[] m = mag; int len = m.length; @@ -3291,7 +3277,7 @@ n = magBitLength; } } - bitLength = n + 1; + bitLengthPlusOne = n + 1; } return n; } @@ -3305,7 +3291,7 @@ * of this BigInteger that differ from its sign bit. */ public int bitCount() { - @SuppressWarnings("deprecation") int bc = bitCount - 1; + int bc = bitCountPlusOne - 1; if (bc == -1) { // bitCount not initialized yet bc = 0; // offset by one to initialize // Count the bits in the magnitude @@ -3319,7 +3305,7 @@ magTrailingZeroCount += Integer.numberOfTrailingZeros(mag[j]); bc += magTrailingZeroCount - 1; } - bitCount = bc + 1; + bitCountPlusOne = bc + 1; } return bc; } @@ -3622,16 +3608,16 @@ */ private static void toString(BigInteger u, StringBuilder sb, int radix, int digits) { - /* If we're smaller than a certain threshold, use the smallToString - method, padding with leading zeroes when necessary. */ + // If we're smaller than a certain threshold, use the smallToString + // method, padding with leading zeroes when necessary. if (u.mag.length <= SCHOENHAGE_BASE_CONVERSION_THRESHOLD) { String s = u.smallToString(radix); // Pad with internal zeros if necessary. // Don't pad if we're at the beginning of the string. if ((s.length() < digits) && (sb.length() > 0)) { - for (int i=s.length(); i < digits; i++) { // May be a faster way to - sb.append('0'); // do this? + for (int i=s.length(); i < digits; i++) { + sb.append('0'); } } @@ -4185,22 +4171,23 @@ } /** - * Returns the index of the int that contains the first nonzero int in the - * little-endian binary representation of the magnitude (int 0 is the - * least significant). If the magnitude is zero, return value is undefined. - */ + * Returns the index of the int that contains the first nonzero int in the + * little-endian binary representation of the magnitude (int 0 is the + * least significant). If the magnitude is zero, return value is undefined. + * + *
Note: never used for a BigInteger with a magnitude of zero. + * @see #getInt. + */ private int firstNonzeroIntNum() { - int fn = firstNonzeroIntNum - 2; + int fn = firstNonzeroIntNumPlusTwo - 2; if (fn == -2) { // firstNonzeroIntNum not initialized yet - fn = 0; - // Search for the first nonzero int int i; int mlen = mag.length; for (i = mlen - 1; i >= 0 && mag[i] == 0; i--) ; fn = mlen - i - 1; - firstNonzeroIntNum = fn + 2; // offset by two to initialize + firstNonzeroIntNumPlusTwo = fn + 2; // offset by two to initialize } return fn; } @@ -4212,16 +4199,17 @@ * Serializable fields for BigInteger. * * @serialField signum int - * signum of this BigInteger. - * @serialField magnitude int[] - * magnitude array of this BigInteger. + * signum of this BigInteger + * @serialField magnitude byte[] + * magnitude array of this BigInteger * @serialField bitCount int - * number of bits in this BigInteger + * appears in the serialized form for backward compatibility * @serialField bitLength int - * the number of bits in the minimal two's-complement - * representation of this BigInteger + * appears in the serialized form for backward compatibility + * @serialField firstNonzeroByteNum int + * appears in the serialized form for backward compatibility * @serialField lowestSetBit int - * lowest set bit in the twos complement representation + * appears in the serialized form for backward compatibility */ private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("signum", Integer.TYPE), @@ -4238,22 +4226,14 @@ * for historical reasons, but it is converted to an array of ints * and the byte array is discarded. * Note: - * The current convention is to initialize the cache fields, bitCount, - * bitLength and lowestSetBit, to 0 rather than some other marker value. - * Therefore, no explicit action to set these fields needs to be taken in - * readObject because those fields already have a 0 value be default since - * defaultReadObject is not being used. + * The current convention is to initialize the cache fields, bitCountPlusOne, + * bitLengthPlusOne and lowestSetBitPlusTwo, to 0 rather than some other + * marker value. Therefore, no explicit action to set these fields needs to + * be taken in readObject because those fields already have a 0 value by + * default since defaultReadObject is not being used. */ private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { - /* - * In order to maintain compatibility with previous serialized forms, - * the magnitude of a BigInteger is serialized as an array of bytes. - * The magnitude field is used as a temporary store for the byte array - * that is deserialized. The cached computation fields should be - * transient but are serialized for compatibility reasons. - */ - // prepare to read the alternate persistent fields ObjectInputStream.GetField fields = s.readFields(); @@ -4317,12 +4297,14 @@ } /** - * Save the {@code BigInteger} instance to a stream. - * The magnitude of a BigInteger is serialized as a byte array for - * historical reasons. - * - * @serialData two necessary fields are written as well as obsolete - * fields for compatibility with older versions. + * Save the {@code BigInteger} instance to a stream. The magnitude of a + * {@code BigInteger} is serialized as a byte array for historical reasons. + * To maintain compatibility with older implementations, the integers + * -1, -1, -2, and -2 are written as the values of the obsolete fields + * {@code bitCount}, {@code bitLength}, {@code lowestSetBit}, and + * {@code firstNonzeroByteNum}, respectively. These values are compatible + * with older implementations, but will be ignored by current + * implementations. */ private void writeObject(ObjectOutputStream s) throws IOException { // set the values of the Serializable fields @@ -4338,7 +4320,7 @@ // save them s.writeFields(); -} + } /** * Returns the mag array as an array of bytes.