diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | java/math/BigDecimal.java | 217 |
2 files changed, 214 insertions, 12 deletions
@@ -1,3 +1,12 @@ +2006-02-22 Anthony Balkissoon <abalkiss@redhat.com> + + * java/math/BigDecimal.java: + (BigDecimal(char[], int, int, MathContext)): New constructor. + (BigDecimal(char[], MathContext)): Likewise. + (BigDecimal(char[])): Likewise. + (BigDecimal(char[], int, int)): Likewise. + (BigDecimal(String)): Fixed handling of exponent and scale. + 2006-02-21 Anthony Balkissoon <abalkiss@redhat.com> * java/math/BigDecimal.java: diff --git a/java/math/BigDecimal.java b/java/math/BigDecimal.java index a666c7714..d4a369c06 100644 --- a/java/math/BigDecimal.java +++ b/java/math/BigDecimal.java @@ -170,6 +170,209 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> } } + /** + * Constructs a BigDecimal from the char subarray and rounding + * according to the MathContext. + * @param in the char array + * @param offset the start of the subarray + * @param len the length of the subarray + * @param mc the MathContext for rounding + * @throws NumberFormatException if the char subarray is not a valid + * BigDecimal representation + * @throws ArithmeticException if the result is inexact but the rounding + * mode is RoundingMode.UNNECESSARY + * @since 1.5 + */ + public BigDecimal(char[] in, int offset, int len, MathContext mc) + { + this(in, offset, len); + // If mc has precision other than zero then we must round. + if (mc.getPrecision() != 0) + { + BigDecimal temp = this.round(mc); + this.intVal = temp.intVal; + this.scale = temp.scale; + this.precision = temp.precision; + } + } + + /** + * Constructs a BigDecimal from the char array and rounding according + * to the MathContext. + * @param in the char array + * @param mc the MathContext + * @throws NumberFormatException if <code>in</code> is not a valid BigDecimal + * representation + * @throws ArithmeticException if the result is inexact but the rounding mode + * is RoundingMode.UNNECESSARY + * @since 1.5 + */ + public BigDecimal(char[] in, MathContext mc) + { + this(in, 0, in.length); + // If mc has precision other than zero then we must round. + if (mc.getPrecision() != 0) + { + BigDecimal temp = this.round(mc); + this.intVal = temp.intVal; + this.scale = temp.scale; + this.precision = temp.precision; + } + } + + /** + * Constructs a BigDecimal from the given char array, accepting the same + * sequence of characters as the BigDecimal(String) constructor. + * @param in the char array + * @throws NumberFormatException if <code>in</code> is not a valid BigDecimal + * representation + * @since 1.5 + */ + public BigDecimal(char[] in) + { + this(in, 0, in.length); + } + + /** + * Constructs a BigDecimal from a char subarray, accepting the same sequence + * of characters as the BigDecimal(String) constructor. + * @param in the char array + * @param offset the start of the subarray + * @param len the length of the subarray + * @throws NumberFormatException if <code>in</code> is not a valid + * BigDecimal representation. + * @since 1.5 + */ + public BigDecimal(char[] in, int offset, int len) + { + // start is the index into the char array where the significand starts + int start = offset; + // end is one greater than the index of the last character used + int end = offset + len; + // point is the index into the char array where the exponent starts + // (or, if there is no exponent, this is equal to end) + int point = offset; + // dot is the index into the char array where the decimal point is + // found, or -1 if there is no decimal point + int dot = -1; + + // The following examples show what these variables mean. Note that + // point and dot don't yet have the correct values, they will be + // properly assigned in a loop later on in this method. + // + // Example 1 + // + // + 1 0 2 . 4 6 9 + // __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ + // + // offset = 2, len = 8, start = 3, dot = 6, point = end = 10 + // + // Example 2 + // + // + 2 3 4 . 6 1 3 E - 1 + // __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ + // + // offset = 2, len = 11, start = 3, dot = 6, point = 10, end = 13 + // + // Example 3 + // + // - 1 2 3 4 5 e 7 + // __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ + // + // offset = 2, len = 8, start = 3, dot = -1, point = 8, end = 10 + + // Determine the sign of the number. + boolean negative = false; + if (in[offset] == '+') + { + ++start; + ++point; + } + else if (in[offset] == '-') + { + ++start; + ++point; + negative = true; + } + + // Check each character looking for the decimal point and the + // start of the exponent. + while (point < end) + { + char c = in[point]; + if (c == '.') + { + // If dot != -1 then we've seen more than one decimal point. + if (dot != -1) + throw new NumberFormatException("multiple `.'s in number"); + dot = point; + } + // Break when we reach the start of the exponent. + else if (c == 'e' || c == 'E') + break; + // Throw an exception if the character was not a decimal or an + // exponent and is not a digit. + else if (!Character.isDigit(c)) + throw new NumberFormatException("unrecognized character at " + point + + ": " + c); + ++point; + } + + // val is a StringBuilder from which we'll create a BigInteger + // which will be the unscaled value for this BigDecimal + StringBuilder val = new StringBuilder(point - start - 1); + if (dot != -1) + { + // If there was a decimal we must combine the two parts that + // contain only digits and we must set the scale properly. + val.append(in, start, dot - start); + val.append(in, dot + 1, point - dot - 1); + scale = point - 1 - dot; + } + else + { + // If there was no decimal then the unscaled value is just the number + // formed from all the digits and the scale is zero. + val.append(in, start, point - start); + scale = 0; + } + if (val.length() == 0) + throw new NumberFormatException("no digits seen"); + + // Prepend a negative sign if necessary. + if (negative) + val.insert(0, '-'); + intVal = new BigInteger(val.toString()); + + // Now parse exponent. + // If point < end that means we broke out of the previous loop when we + // saw an 'e' or an 'E'. + if (point < end) + { + point++; + // Ignore a '+' sign. + if (in[point] == '+') + point++; + + // Throw an exception if there were no digits found after the 'e' + // or 'E'. + if (point >= end) + throw new NumberFormatException("no exponent following e or E"); + + try + { + // Adjust the scale according to the exponent. + // Remember that the value of a BigDecimal is + // unscaledValue x Math.pow(10, -scale) + scale -= Integer.parseInt(new String(in, point, end - point)); + } + catch (NumberFormatException ex) + { + throw new NumberFormatException("malformed exponent"); + } + } + } + public BigDecimal (String num) throws NumberFormatException { int len = num.length(); @@ -233,18 +436,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> throw new NumberFormatException ("no exponent following e or E"); try - { - int exp = Integer.parseInt (num.substring (point)); - exp -= scale; - if (signum () == 0) - scale = 0; - else if (exp > 0) - { - intVal = intVal.multiply (BigInteger.valueOf (10).pow (exp)); - scale = 0; - } - else - scale = - exp; + { + scale -= Integer.parseInt (num.substring (point)); } catch (NumberFormatException ex) { |