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+/* 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();
+ }
+}