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Diffstat (limited to 'libjava/classpath/java/math/MathContext.java')
-rw-r--r-- | libjava/classpath/java/math/MathContext.java | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/libjava/classpath/java/math/MathContext.java b/libjava/classpath/java/math/MathContext.java new file mode 100644 index 000000000..161149540 --- /dev/null +++ b/libjava/classpath/java/math/MathContext.java @@ -0,0 +1,198 @@ +/* MathContext.java -- + Copyright (C) 1999, 2000, 2002, 2004, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.math; + +import java.io.Serializable; + +/** + * Immutable objects describing settings such as rounding mode and digit + * precision for numerical operations such as those in the BigDecimal class. + * @author Anthony Balkissoon abalkiss at redhat dot com + * + */ +public final class MathContext implements Serializable +{ + /** A MathContext for unlimited precision arithmetic * */ + public static final MathContext UNLIMITED = + new MathContext(0, RoundingMode.HALF_UP); + + /** + * A MathContext for the IEEE 754R Decimal32 format - 7 digit preicision and + * HALF_EVEN rounding. + */ + public static final MathContext DECIMAL32 = + new MathContext(7, RoundingMode.HALF_EVEN); + + /** + * A MathContext for the IEEE 754R Decimal64 format - 16 digit preicision and + * HALF_EVEN rounding. + */ + public static final MathContext DECIMAL64 = + new MathContext(16, RoundingMode.HALF_EVEN); + + /** + * A MathContext for the IEEE 754R Decimal128 format - 34 digit preicision and + * HALF_EVEN rounding. + */ + public static final MathContext DECIMAL128 = + new MathContext(34, RoundingMode.HALF_EVEN); + + /** + * This is the serialVersionUID reported here: + * java.sun.com/j2se/1.5.0/docs/api/serialized-form.html#java.math.MathContext + */ + private static final long serialVersionUID = 5579720004786848255L; + + private int precision; + + private RoundingMode roundMode; + + /** + * Constructs a new MathContext with the specified precision and with HALF_UP + * rounding. + * @param setPrecision the precision for the new MathContext + * + * @throws IllegalArgumentException if precision is < 0. + */ + public MathContext(int setPrecision) + { + this(setPrecision, RoundingMode.HALF_UP); + } + + /** + * Constructs a new MathContext with the specified precision and rounding + * mode. + * @param setPrecision the precision + * @param setRoundingMode the rounding mode + * + * @throws IllegalArgumentException if precision is < 0. + */ + public MathContext(int setPrecision, RoundingMode setRoundingMode) + { + if (setPrecision < 0) + throw new IllegalArgumentException("Precision cannot be less than zero."); + precision = setPrecision; + roundMode = setRoundingMode; + } + + /** + * Constructs a MathContext from a String that has the same form as one + * produced by the toString() method. + * @param val + * + * @throws IllegalArgumentException if the String is not in the correct + * format or if the precision specified is < 0. + */ + public MathContext(String val) + { + try + { + int roundingModeIndex = val.indexOf("roundingMode", 10); + precision = Integer.parseInt(val.substring(10, roundingModeIndex - 1)); + roundMode = RoundingMode.valueOf(val.substring(roundingModeIndex + 13)); + } + catch (NumberFormatException nfe) + { + throw new IllegalArgumentException("String not in correct format"); + } + catch (IllegalArgumentException iae) + { + throw new IllegalArgumentException("String not in correct format"); + } + if (precision < 0) + throw new IllegalArgumentException("Precision cannot be less than 0."); + } + + /** + * Returns true if x is a MathContext and has the same precision setting + * and rounding mode as this MathContext. + * + * @return true if the above conditions hold + */ + public boolean equals(Object x) + { + if (!(x instanceof MathContext)) + return false; + MathContext mc = (MathContext)x; + return mc.precision == this.precision + && mc.roundMode.equals(this.roundMode); + } + + /** + * Returns the precision setting. + * @return the precision setting. + */ + public int getPrecision() + { + return precision; + } + + /** + * Returns the rounding mode setting. This will be one of + * RoundingMode.CEILING, RoundingMode.DOWN, RoundingMode.FLOOR, + * RoundingMode.HALF_DOWN, RoundingMode.HALF_EVEN, RoundingMode.HALF_UP, + * RoundingMode.UNNECESSARY, or RoundingMode.UP. + * @return the rounding mode setting. + */ + public RoundingMode getRoundingMode() + { + return roundMode; + } + + /** + * Returns "precision=p roundingMode=MODE" where p is an int giving the + * precision and MODE is UP, DOWN, HALF_UP, HALF_DOWN, HALF_EVEN, CEILING, + * FLOOR, or UNNECESSARY corresponding to rounding modes. + * + * @return a String describing this MathContext + */ + public String toString() + { + return "precision="+precision+" roundingMode="+roundMode; + } + + /** + * Returns the hashcode for this MathContext. + * @return the hashcode for this MathContext. + */ + public int hashCode() + { + return precision ^ roundMode.hashCode(); + } +} |