| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2002-2003 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Commons", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.commons.lang.math; |
| |
| import java.math.BigDecimal; |
| import java.math.BigInteger; |
| |
| import org.apache.commons.lang.NullArgumentException; |
| |
| /** |
| * <p>Provides extra functionality for Java Number classes.</p> |
| * |
| * @author <a href="mailto:bayard@generationjava.com">Henri Yandell</a> |
| * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a> |
| * @author Stephen Colebourne |
| * @author <a href="mailto:steve.downey@netfolio.com">Steve Downey</a> |
| * @author Eric Pugh |
| * @author Phil Steitz |
| * @author Matthew Hawthorne |
| * @since 2.0 |
| * @version $Id: NumberUtils.java,v 1.3 2003/07/14 22:25:05 bayard Exp $ |
| */ |
| public final class NumberUtils { |
| |
| /** Reusable Long constant for zero. */ |
| public static final Long LONG_ZERO = new Long(0L); |
| /** Reusable Long constant for one. */ |
| public static final Long LONG_ONE = new Long(1L); |
| /** Reusable Long constant for minus one. */ |
| public static final Long LONG_MINUS_ONE = new Long(-1L); |
| /** Reusable Integer constant for zero. */ |
| public static final Integer INTEGER_ZERO = new Integer(0); |
| /** Reusable Integer constant for one. */ |
| public static final Integer INTEGER_ONE = new Integer(1); |
| /** Reusable Integer constant for minus one. */ |
| public static final Integer INTEGER_MINUS_ONE = new Integer(-1); |
| /** Reusable Short constant for zero. */ |
| public static final Short SHORT_ZERO = new Short((short) 0); |
| /** Reusable Short constant for one. */ |
| public static final Short SHORT_ONE = new Short((short) 1); |
| /** Reusable Short constant for minus one. */ |
| public static final Short SHORT_MINUS_ONE = new Short((short) -1); |
| /** Reusable Byte constant for zero. */ |
| public static final Byte BYTE_ZERO = new Byte((byte) 0); |
| /** Reusable Byte constant for one. */ |
| public static final Byte BYTE_ONE = new Byte((byte) 1); |
| /** Reusable Byte constant for minus one. */ |
| public static final Byte BYTE_MINUS_ONE = new Byte((byte) -1); |
| /** Reusable Double constant for zero. */ |
| public static final Double DOUBLE_ZERO = new Double(0.0d); |
| /** Reusable Double constant for one. */ |
| public static final Double DOUBLE_ONE = new Double(1.0d); |
| /** Reusable Double constant for minus one. */ |
| public static final Double DOUBLE_MINUS_ONE = new Double(-1.0d); |
| /** Reusable Float constant for zero. */ |
| public static final Float FLOAT_ZERO = new Float(0.0f); |
| /** Reusable Float constant for one. */ |
| public static final Float FLOAT_ONE = new Float(1.0f); |
| /** Reusable Float constant for minus one. */ |
| public static final Float FLOAT_MINUS_ONE = new Float(-1.0f); |
| |
| /** |
| * <p><code>NumberUtils</code> instances should NOT be constructed in standard programming. |
| * Instead, the class should be used as <code>NumberUtils.stringToInt("6");</code>.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean instance |
| * to operate.</p> |
| */ |
| public NumberUtils() { |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Convert a <code>String</code> to an <code>int</code>, returning |
| * <code>zero</code> if the conversion fails.</p> |
| * |
| * @param str the string to convert |
| * @return the int represented by the string, or <code>zero</code> if |
| * conversion fails |
| */ |
| public static int stringToInt(String str) { |
| return stringToInt(str, 0); |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to an <code>int</code>, returning a |
| * default value if the conversion fails.</p> |
| * |
| * @param str the string to convert |
| * @param defaultValue the default value |
| * @return the int represented by the string, or the default if conversion fails |
| */ |
| public static int stringToInt(String str, int defaultValue) { |
| try { |
| return Integer.parseInt(str); |
| } catch (NumberFormatException nfe) { |
| return defaultValue; |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| // must handle Long, Float, Integer, Float, Short, |
| // BigDecimal, BigInteger and Byte |
| // useful methods: |
| // Byte.decode(String) |
| // Byte.valueOf(String,int radix) |
| // Byte.valueOf(String) |
| // Double.valueOf(String) |
| // Float.valueOf(String) |
| // new Float(String) |
| // Integer.valueOf(String,int radix) |
| // Integer.valueOf(String) |
| // Integer.decode(String) |
| // Integer.getInteger(String) |
| // Integer.getInteger(String,int val) |
| // Integer.getInteger(String,Integer val) |
| // new Integer(String) |
| // new Double(String) |
| // new Byte(String) |
| // new Long(String) |
| // Long.getLong(String) |
| // Long.getLong(String,int) |
| // Long.getLong(String,Integer) |
| // Long.valueOf(String,int) |
| // Long.valueOf(String) |
| // new Short(String) |
| // Short.decode(String) |
| // Short.valueOf(String,int) |
| // Short.valueOf(String) |
| // new BigDecimal(String) |
| // new BigInteger(String) |
| // new BigInteger(String,int radix) |
| // Possible inputs: |
| // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd |
| // plus minus everything. Prolly more. A lot are not separable. |
| |
| /** |
| * <p>Turns a string value into a java.lang.Number.</p> |
| * |
| * <p>First, the value is examined for a type qualifier on the end |
| * (<code>'f','F','d','D','l','L'</code>). If it is found, it starts |
| * trying to create succissively larger types from the type specified |
| * until one is found that can hold the value.</p> |
| * |
| * <p>If a type specifier is not found, it will check for a decimal point |
| * and then try successively larger types from <code>Integer</code> to |
| * <code>BigInteger</code> and from <code>Float</code> to |
| * <code>BigDecimal</code>.</p> |
| * |
| * <p>If the string starts with <code>0x</code> or <code>-0x</code>, it |
| * will be interpreted as a hexadecimal integer. Values with leading |
| * <code>0</code>'s will not be interpreted as octal.</p> |
| * |
| * @param val String containing a number |
| * @return Number created from the string |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static Number createNumber(String val) throws NumberFormatException { |
| if (val == null) { |
| return null; |
| } |
| if (val.length() == 0) { |
| throw new NumberFormatException("\"\" is not a valid number."); |
| } |
| if (val.startsWith("--")) { |
| // this is protection for poorness in java.lang.BigDecimal. |
| // it accepts this as a legal value, but it does not appear |
| // to be in specification of class. OS X Java parses it to |
| // a wrong value. |
| return null; |
| } |
| if (val.startsWith("0x") || val.startsWith("-0x")) { |
| return createInteger(val); |
| } |
| char lastChar = val.charAt(val.length() - 1); |
| String mant; |
| String dec; |
| String exp; |
| int decPos = val.indexOf('.'); |
| int expPos = val.indexOf('e') + val.indexOf('E') + 1; |
| |
| if (decPos > -1) { |
| |
| if (expPos > -1) { |
| if (expPos < decPos) { |
| throw new NumberFormatException(val + " is not a valid number."); |
| } |
| dec = val.substring(decPos + 1, expPos); |
| } else { |
| dec = val.substring(decPos + 1); |
| } |
| mant = val.substring(0, decPos); |
| } else { |
| if (expPos > -1) { |
| mant = val.substring(0, expPos); |
| } else { |
| mant = val; |
| } |
| dec = null; |
| } |
| if (!Character.isDigit(lastChar)) { |
| if (expPos > -1 && expPos < val.length() - 1) { |
| exp = val.substring(expPos + 1, val.length() - 1); |
| } else { |
| exp = null; |
| } |
| //Requesting a specific type.. |
| String numeric = val.substring(0, val.length() - 1); |
| boolean allZeros = isAllZeros(mant) && isAllZeros(exp); |
| switch (lastChar) { |
| case 'l' : |
| case 'L' : |
| if (dec == null |
| && exp == null |
| && isDigits(numeric.substring(1)) |
| && (numeric.charAt(0) == '-' || Character.isDigit(numeric.charAt(0)))) { |
| try { |
| return createLong(numeric); |
| } catch (NumberFormatException nfe) { |
| //Too big for a long |
| } |
| return createBigInteger(numeric); |
| |
| } |
| throw new NumberFormatException(val + " is not a valid number."); |
| case 'f' : |
| case 'F' : |
| try { |
| Float f = NumberUtils.createFloat(numeric); |
| if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) { |
| //If it's too big for a float or the float value = 0 and the string |
| //has non-zeros in it, then float doens't have the presision we want |
| return f; |
| } |
| |
| } catch (NumberFormatException nfe) { |
| } |
| //Fall through |
| case 'd' : |
| case 'D' : |
| try { |
| Double d = NumberUtils.createDouble(numeric); |
| if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) { |
| return d; |
| } |
| } catch (NumberFormatException nfe) { |
| } |
| try { |
| return createBigDecimal(numeric); |
| } catch (NumberFormatException e) { |
| } |
| //Fall through |
| default : |
| throw new NumberFormatException(val + " is not a valid number."); |
| |
| } |
| } else { |
| //User doesn't have a preference on the return type, so let's start |
| //small and go from there... |
| if (expPos > -1 && expPos < val.length() - 1) { |
| exp = val.substring(expPos + 1, val.length()); |
| } else { |
| exp = null; |
| } |
| if (dec == null && exp == null) { |
| //Must be an int,long,bigint |
| try { |
| return createInteger(val); |
| } catch (NumberFormatException nfe) { |
| } |
| try { |
| return createLong(val); |
| } catch (NumberFormatException nfe) { |
| } |
| return createBigInteger(val); |
| |
| } else { |
| //Must be a float,double,BigDec |
| boolean allZeros = isAllZeros(mant) && isAllZeros(exp); |
| try { |
| Float f = createFloat(val); |
| if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) { |
| return f; |
| } |
| } catch (NumberFormatException nfe) { |
| } |
| try { |
| Double d = createDouble(val); |
| if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) { |
| return d; |
| } |
| } catch (NumberFormatException nfe) { |
| } |
| |
| return createBigDecimal(val); |
| |
| } |
| } |
| } |
| |
| /** |
| * <p>Utility method for {@link #createNumber(java.lang.String)}.</p> |
| * |
| * <p>Returns <code>true</code> if s is <code>null</code>.</p> |
| * |
| * @param s the String to check |
| * @return if it is all zeros or <code>null</code> |
| */ |
| private static boolean isAllZeros(String s) { |
| if (s == null) { |
| return true; |
| } |
| for (int i = s.length() - 1; i >= 0; i--) { |
| if (s.charAt(i) != '0') { |
| return false; |
| } |
| } |
| return s.length() > 0; |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Convert a <code>String</code> to a <code>Float</code>.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>Float</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static Float createFloat(String val) { |
| return Float.valueOf(val); |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to a <code>Double</code>.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>Double</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static Double createDouble(String val) { |
| return Double.valueOf(val); |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to a <code>Integer</code>, handling |
| * hex and octal notations.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>Integer</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static Integer createInteger(String val) { |
| // decode() handles 0xAABD and 0777 (hex and octal) as well. |
| return Integer.decode(val); |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to a <code>Long</code>.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>Long</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static Long createLong(String val) { |
| return Long.valueOf(val); |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to a <code>BigInteger</code>.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>BigInteger</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static BigInteger createBigInteger(String val) { |
| BigInteger bi = new BigInteger(val); |
| return bi; |
| } |
| |
| /** |
| * <p>Convert a <code>String</code> to a <code>BigDecimal</code>.</p> |
| * |
| * @param val a <code>String</code> to convert |
| * @return converted <code>BigDecimal</code> |
| * @throws NumberFormatException if the value cannot be converted |
| */ |
| public static BigDecimal createBigDecimal(String val) { |
| BigDecimal bd = new BigDecimal(val); |
| return bd; |
| } |
| |
| // Min in array |
| //-------------------------------------------------------------------- |
| /** |
| * <p>Returns the minimum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static long min(long[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns min |
| long min = array[0]; |
| for (int i = 1; i < array.length; i++) { |
| if (array[i] < min) { |
| min = array[i]; |
| } |
| } |
| |
| return min; |
| } |
| |
| /** |
| * <p>Returns the minimum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static int min(int[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns min |
| int min = array[0]; |
| for (int j = 1; j < array.length; j++) { |
| if (array[j] < min) { |
| min = array[j]; |
| } |
| } |
| |
| return min; |
| } |
| |
| /** |
| * <p>Returns the minimum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static short min(short[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns min |
| short min = array[0]; |
| for (int i = 1; i < array.length; i++) { |
| if (array[i] < min) { |
| min = array[i]; |
| } |
| } |
| |
| return min; |
| } |
| |
| /** |
| * <p>Returns the minimum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static double min(double[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns min |
| double min = array[0]; |
| for (int i = 1; i < array.length; i++) { |
| if (array[i] < min) { |
| min = array[i]; |
| } |
| } |
| |
| return min; |
| } |
| |
| /** |
| * <p>Returns the minimum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static float min(float[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns min |
| float min = array[0]; |
| for (int i = 1; i < array.length; i++) { |
| if (array[i] < min) { |
| min = array[i]; |
| } |
| } |
| |
| return min; |
| } |
| |
| // Max in array |
| //-------------------------------------------------------------------- |
| /** |
| * <p>Returns the maximum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static long max(long[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns max |
| long max = array[0]; |
| for (int j = 1; j < array.length; j++) { |
| if (array[j] > max) { |
| max = array[j]; |
| } |
| } |
| |
| return max; |
| } |
| |
| /** |
| * <p>Returns the maximum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static int max(int[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns max |
| int max = array[0]; |
| for (int j = 1; j < array.length; j++) { |
| if (array[j] > max) { |
| max = array[j]; |
| } |
| } |
| |
| return max; |
| } |
| |
| /** |
| * <p>Returns the maximum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static short max(short[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns max |
| short max = array[0]; |
| for (int i = 1; i < array.length; i++) { |
| if (array[i] > max) { |
| max = array[i]; |
| } |
| } |
| |
| return max; |
| } |
| |
| /** |
| * <p>Returns the maximum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static double max(double[] array) { |
| // Validates input |
| if (array== null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns max |
| double max = array[0]; |
| for (int j = 1; j < array.length; j++) { |
| if (array[j] > max) { |
| max = array[j]; |
| } |
| } |
| |
| return max; |
| } |
| |
| /** |
| * <p>Returns the maximum value in an array.</p> |
| * |
| * @param array an array |
| * @return the minimum value in the array |
| * @throws NullArgumentException if <code>array</code> is <code>null</code> |
| * @throws IllegalArgumentException if <code>array</code> is empty |
| */ |
| public static float max(float[] array) { |
| // Validates input |
| if (array == null) { |
| throw new NullArgumentException("Array"); |
| } else if (array.length == 0) { |
| throw new IllegalArgumentException("Array cannot be empty."); |
| } |
| |
| // Finds and returns max |
| float max = array[0]; |
| for (int j = 1; j < array.length; j++) { |
| if (array[j] > max) { |
| max = array[j]; |
| } |
| } |
| |
| return max; |
| } |
| |
| // 3 param min |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the minimum of three <code>long</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static long min(long a, long b, long c) { |
| if (b < a) { |
| a = b; |
| } |
| if (c < a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>int</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static int min(int a, int b, int c) { |
| if (b < a) { |
| a = b; |
| } |
| if (c < a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>short</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static short min(short a, short b, short c) { |
| if (b < a) { |
| a = b; |
| } |
| if (c < a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>byte</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static byte min(byte a, byte b, byte c) { |
| if (b < a) { |
| a = b; |
| } |
| if (c < a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>double</code> values.</p> |
| * |
| * <p>If any value is <code>NaN</code>, <code>NaN</code> is |
| * returned. Infinity is handled.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static double min(double a, double b, double c) { |
| return Math.min(Math.min(a, b), c); |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>float</code> values.</p> |
| * |
| * <p>If any value is <code>NaN</code>, <code>NaN</code> is |
| * returned. Infinity is handled.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| public static float min(float a, float b, float c) { |
| return Math.min(Math.min(a, b), c); |
| } |
| |
| // 3 param max |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the maximum of three <code>long</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static long max(long a, long b, long c) { |
| if (b > a) { |
| a = b; |
| } |
| if (c > a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the maximum of three <code>int</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static int max(int a, int b, int c) { |
| if (b > a) { |
| a = b; |
| } |
| if (c > a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the maximum of three <code>short</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static short max(short a, short b, short c) { |
| if (b > a) { |
| a = b; |
| } |
| if (c > a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the maximum of three <code>byte</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static byte max(byte a, byte b, byte c) { |
| if (b > a) { |
| a = b; |
| } |
| if (c > a) { |
| a = c; |
| } |
| return a; |
| } |
| |
| /** |
| * <p>Gets the maximum of three <code>double</code> values.</p> |
| * |
| * <p>If any value is <code>NaN</code>, <code>NaN</code> is |
| * returned. Infinity is handled.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static double max(double a, double b, double c) { |
| return Math.max(Math.max(a, b), c); |
| } |
| |
| /** |
| * <p>Gets the maximum of three <code>float</code> values.</p> |
| * |
| * <p>If any value is <code>NaN</code>, <code>NaN</code> is |
| * returned. Infinity is handled.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the largest of the values |
| */ |
| public static float max(float a, float b, float c) { |
| return Math.max(Math.max(a, b), c); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Compares two <code>doubles</code> for order.</p> |
| * |
| * <p>This method is more comprehensive than the standard Java greater |
| * than, less than and equals operators.</p> |
| * <ul> |
| * <li>It returns <code>-1</code> if the first value is less than the second.</li> |
| * <li>It returns <code>+1</code> if the first value is greater than the second.</li> |
| * <li>It returns <code>0</code> if the values are equal.</li> |
| * </ul> |
| * |
| * <p> |
| * The ordering is as follows, largest to smallest: |
| * <ul> |
| * <li>NaN |
| * <li>Positive infinity |
| * <li>Maximum double |
| * <li>Normal positve numbers |
| * <li>+0.0 |
| * <li>-0.0 |
| * <li>Normal negative numbers |
| * <li>Minimum double (<code>-Double.MAX_VALUE</code>) |
| * <li>Negative infinity |
| * </ul> |
| * </p> |
| * |
| * <p>Comparing <code>NaN</code> with <code>NaN</code> will |
| * return <code>0</code>.</p> |
| * |
| * @param lhs the first <code>double</code> |
| * @param rhs the second <code>double</code> |
| * @return <code>-1</code> if lhs is less, <code>+1</code> if greater, |
| * <code>0</code> if equal to rhs |
| */ |
| public static int compare(double lhs, double rhs) { |
| if (lhs < rhs) { |
| return -1; |
| } |
| if (lhs > rhs) { |
| return +1; |
| } |
| // Need to compare bits to handle 0.0 == -0.0 being true |
| // compare should put -0.0 < +0.0 |
| // Two NaNs are also == for compare purposes |
| // where NaN == NaN is false |
| long lhsBits = Double.doubleToLongBits(lhs); |
| long rhsBits = Double.doubleToLongBits(rhs); |
| if (lhsBits == rhsBits) { |
| return 0; |
| } |
| // Something exotic! A comparison to NaN or 0.0 vs -0.0 |
| // Fortunately NaN's long is > than everything else |
| // Also negzeros bits < poszero |
| // NAN: 9221120237041090560 |
| // MAX: 9218868437227405311 |
| // NEGZERO: -9223372036854775808 |
| if (lhsBits < rhsBits) { |
| return -1; |
| } else { |
| return +1; |
| } |
| } |
| |
| /** |
| * <p>Compares two floats for order.</p> |
| * |
| * <p>This method is more comprhensive than the standard Java greater than, |
| * less than and equals operators.</p> |
| * <ul> |
| * <li>It returns <code>-1</code> if the first value is less than the second. |
| * <li>It returns <code>+1</code> if the first value is greater than the second. |
| * <li>It returns <code>0</code> if the values are equal. |
| * </ul> |
| * |
| * <p> The ordering is as follows, largest to smallest: |
| * <ul> |
| * <li>NaN |
| * <li>Positive infinity |
| * <li>Maximum float |
| * <li>Normal positve numbers |
| * <li>+0.0 |
| * <li>-0.0 |
| * <li>Normal negative numbers |
| * <li>Minimum float (<code>-Float.MAX_VALUE</code>) |
| * <li>Negative infinity |
| * </ul> |
| * |
| * <p>Comparing <code>NaN</code> with <code>NaN</code> will return |
| * <code>0</code>.</p> |
| * |
| * @param lhs the first <code>float</code> |
| * @param rhs the second <code>float</code> |
| * @return <code>-1</code> if lhs is less, <code>+1</code> if greater, |
| * <code>0</code> if equal to rhs |
| */ |
| public static int compare(float lhs, float rhs) { |
| if (lhs < rhs) { |
| return -1; |
| } |
| if (lhs > rhs) { |
| return +1; |
| } |
| //Need to compare bits to handle 0.0 == -0.0 being true |
| // compare should put -0.0 < +0.0 |
| // Two NaNs are also == for compare purposes |
| // where NaN == NaN is false |
| int lhsBits = Float.floatToIntBits(lhs); |
| int rhsBits = Float.floatToIntBits(rhs); |
| if (lhsBits == rhsBits) { |
| return 0; |
| } |
| //Something exotic! A comparison to NaN or 0.0 vs -0.0 |
| //Fortunately NaN's int is > than everything else |
| //Also negzeros bits < poszero |
| //NAN: 2143289344 |
| //MAX: 2139095039 |
| //NEGZERO: -2147483648 |
| if (lhsBits < rhsBits) { |
| return -1; |
| } else { |
| return +1; |
| } |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks whether the <code>String</code> contains only |
| * digit characters.</p> |
| * |
| * <p><code>Null</code> and empty String will return |
| * <code>false</code>.</p> |
| * |
| * @param str the <code>String</code> to check |
| * @return <code>true</code> if str contains only unicode numeric |
| */ |
| public static boolean isDigits(String str) { |
| if ((str == null) || (str.length() == 0)) { |
| return false; |
| } |
| for (int i = 0; i < str.length(); i++) { |
| if (!Character.isDigit(str.charAt(i))) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks whether the String a valid Java number.</p> |
| * |
| * <p>Valid numbers include hexadecimal marked with the <code>0x</code> |
| * qualifier, scientific notation and numbers marked with a type |
| * qualifier (e.g. 123L).</p> |
| * |
| * <p><code>Null</code> and empty String will return |
| * <code>false</code>.</p> |
| * |
| * @param str the <code>String</code> to check |
| * @return <code>true</code> if the string is a correctly formatted number |
| */ |
| public static boolean isNumber(String str) { |
| if ((str == null) || (str.length() == 0)) { |
| return false; |
| } |
| char[] chars = str.toCharArray(); |
| int sz = chars.length; |
| boolean hasExp = false; |
| boolean hasDecPoint = false; |
| boolean allowSigns = false; |
| boolean foundDigit = false; |
| // deal with any possible sign up front |
| int start = (chars[0] == '-') ? 1 : 0; |
| if (sz > start + 1) { |
| if (chars[start] == '0' && chars[start + 1] == 'x') { |
| int i = start + 2; |
| if (i == sz) { |
| return false; // str == "0x" |
| } |
| // checking hex (it can't be anything else) |
| for (; i < chars.length; i++) { |
| if ((chars[i] < '0' || chars[i] > '9') |
| && (chars[i] < 'a' || chars[i] > 'f') |
| && (chars[i] < 'A' || chars[i] > 'F')) { |
| return false; |
| } |
| } |
| return true; |
| } |
| } |
| sz--; // don't want to loop to the last char, check it afterwords |
| // for type qualifiers |
| int i = start; |
| // loop to the next to last char or to the last char if we need another digit to |
| // make a valid number (e.g. chars[0..5] = "1234E") |
| while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) { |
| if (chars[i] >= '0' && chars[i] <= '9') { |
| foundDigit = true; |
| allowSigns = false; |
| |
| } else if (chars[i] == '.') { |
| if (hasDecPoint || hasExp) { |
| // two decimal points or dec in exponent |
| return false; |
| } |
| hasDecPoint = true; |
| } else if (chars[i] == 'e' || chars[i] == 'E') { |
| // we've already taken care of hex. |
| if (hasExp) { |
| // two E's |
| return false; |
| } |
| if (!foundDigit) { |
| return false; |
| } |
| hasExp = true; |
| allowSigns = true; |
| } else if (chars[i] == '+' || chars[i] == '-') { |
| if (!allowSigns) { |
| return false; |
| } |
| allowSigns = false; |
| foundDigit = false; // we need a digit after the E |
| } else { |
| return false; |
| } |
| i++; |
| } |
| if (i < chars.length) { |
| if (chars[i] >= '0' && chars[i] <= '9') { |
| // no type qualifier, OK |
| return true; |
| } |
| if (chars[i] == 'e' || chars[i] == 'E') { |
| // can't have an E at the last byte |
| return false; |
| } |
| if (!allowSigns |
| && (chars[i] == 'd' |
| || chars[i] == 'D' |
| || chars[i] == 'f' |
| || chars[i] == 'F')) { |
| return foundDigit; |
| } |
| if (chars[i] == 'l' |
| || chars[i] == 'L') { |
| // not allowing L with an exponoent |
| return foundDigit && !hasExp; |
| } |
| // last character is illegal |
| return false; |
| } |
| // allowSigns is true iff the val ends in 'E' |
| // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass |
| return !allowSigns && foundDigit; |
| } |
| |
| } |