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Java example source code file (NumberUtils.java)

This example Java source code file (NumberUtils.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

array, bigdecimal, biginteger, byte, double, float, integer, ioobe, long, math, nopmd, numberformatexception, numberutils, reflection, short, string

The NumberUtils.java Java example source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang3.math;

import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

/**
 * <p>Provides extra functionality for Java Number classes.

* * @since 2.0 */ public class NumberUtils { /** Reusable Long constant for zero. */ public static final Long LONG_ZERO = Long.valueOf(0L); /** Reusable Long constant for one. */ public static final Long LONG_ONE = Long.valueOf(1L); /** Reusable Long constant for minus one. */ public static final Long LONG_MINUS_ONE = Long.valueOf(-1L); /** Reusable Integer constant for zero. */ public static final Integer INTEGER_ZERO = Integer.valueOf(0); /** Reusable Integer constant for one. */ public static final Integer INTEGER_ONE = Integer.valueOf(1); /** Reusable Integer constant for minus one. */ public static final Integer INTEGER_MINUS_ONE = Integer.valueOf(-1); /** Reusable Short constant for zero. */ public static final Short SHORT_ZERO = Short.valueOf((short) 0); /** Reusable Short constant for one. */ public static final Short SHORT_ONE = Short.valueOf((short) 1); /** Reusable Short constant for minus one. */ public static final Short SHORT_MINUS_ONE = Short.valueOf((short) -1); /** Reusable Byte constant for zero. */ public static final Byte BYTE_ZERO = Byte.valueOf((byte) 0); /** Reusable Byte constant for one. */ public static final Byte BYTE_ONE = Byte.valueOf((byte) 1); /** Reusable Byte constant for minus one. */ public static final Byte BYTE_MINUS_ONE = Byte.valueOf((byte) -1); /** Reusable Double constant for zero. */ public static final Double DOUBLE_ZERO = Double.valueOf(0.0d); /** Reusable Double constant for one. */ public static final Double DOUBLE_ONE = Double.valueOf(1.0d); /** Reusable Double constant for minus one. */ public static final Double DOUBLE_MINUS_ONE = Double.valueOf(-1.0d); /** Reusable Float constant for zero. */ public static final Float FLOAT_ZERO = Float.valueOf(0.0f); /** Reusable Float constant for one. */ public static final Float FLOAT_ONE = Float.valueOf(1.0f); /** Reusable Float constant for minus one. */ public static final Float FLOAT_MINUS_ONE = Float.valueOf(-1.0f); /** * <p>NumberUtils instances should NOT be constructed in standard programming. * Instead, the class should be used as <code>NumberUtils.toInt("6");.

* * <p>This constructor is public to permit tools that require a JavaBean instance * to operate.</p> */ public NumberUtils() { super(); } //----------------------------------------------------------------------- /** * <p>Convert a String to an int, returning * <code>zero if the conversion fails.

* * <p>If the string is null, zero is returned.

* * <pre> * NumberUtils.toInt(null) = 0 * NumberUtils.toInt("") = 0 * NumberUtils.toInt("1") = 1 * </pre> * * @param str the string to convert, may be null * @return the int represented by the string, or <code>zero if * conversion fails * @since 2.1 */ public static int toInt(final String str) { return toInt(str, 0); } /** * <p>Convert a String to an int, returning a * default value if the conversion fails.</p> * * <p>If the string is null, the default value is returned.

* * <pre> * NumberUtils.toInt(null, 1) = 1 * NumberUtils.toInt("", 1) = 1 * NumberUtils.toInt("1", 0) = 1 * </pre> * * @param str the string to convert, may be null * @param defaultValue the default value * @return the int represented by the string, or the default if conversion fails * @since 2.1 */ public static int toInt(final String str, final int defaultValue) { if(str == null) { return defaultValue; } try { return Integer.parseInt(str); } catch (final NumberFormatException nfe) { return defaultValue; } } /** * <p>Convert a String to a long, returning * <code>zero if the conversion fails.

* * <p>If the string is null, zero is returned.

* * <pre> * NumberUtils.toLong(null) = 0L * NumberUtils.toLong("") = 0L * NumberUtils.toLong("1") = 1L * </pre> * * @param str the string to convert, may be null * @return the long represented by the string, or <code>0 if * conversion fails * @since 2.1 */ public static long toLong(final String str) { return toLong(str, 0L); } /** * <p>Convert a String to a long, returning a * default value if the conversion fails.</p> * * <p>If the string is null, the default value is returned.

* * <pre> * NumberUtils.toLong(null, 1L) = 1L * NumberUtils.toLong("", 1L) = 1L * NumberUtils.toLong("1", 0L) = 1L * </pre> * * @param str the string to convert, may be null * @param defaultValue the default value * @return the long represented by the string, or the default if conversion fails * @since 2.1 */ public static long toLong(final String str, final long defaultValue) { if (str == null) { return defaultValue; } try { return Long.parseLong(str); } catch (final NumberFormatException nfe) { return defaultValue; } } /** * <p>Convert a String to a float, returning * <code>0.0f if the conversion fails.

* * <p>If the string str is null, * <code>0.0f is returned.

* * <pre> * NumberUtils.toFloat(null) = 0.0f * NumberUtils.toFloat("") = 0.0f * NumberUtils.toFloat("1.5") = 1.5f * </pre> * * @param str the string to convert, may be <code>null * @return the float represented by the string, or <code>0.0f * if conversion fails * @since 2.1 */ public static float toFloat(final String str) { return toFloat(str, 0.0f); } /** * <p>Convert a String to a float, returning a * default value if the conversion fails.</p> * * <p>If the string str is null, the default * value is returned.</p> * * <pre> * NumberUtils.toFloat(null, 1.1f) = 1.0f * NumberUtils.toFloat("", 1.1f) = 1.1f * NumberUtils.toFloat("1.5", 0.0f) = 1.5f * </pre> * * @param str the string to convert, may be <code>null * @param defaultValue the default value * @return the float represented by the string, or defaultValue * if conversion fails * @since 2.1 */ public static float toFloat(final String str, final float defaultValue) { if (str == null) { return defaultValue; } try { return Float.parseFloat(str); } catch (final NumberFormatException nfe) { return defaultValue; } } /** * <p>Convert a String to a double, returning * <code>0.0d if the conversion fails.

* * <p>If the string str is null, * <code>0.0d is returned.

* * <pre> * NumberUtils.toDouble(null) = 0.0d * NumberUtils.toDouble("") = 0.0d * NumberUtils.toDouble("1.5") = 1.5d * </pre> * * @param str the string to convert, may be <code>null * @return the double represented by the string, or <code>0.0d * if conversion fails * @since 2.1 */ public static double toDouble(final String str) { return toDouble(str, 0.0d); } /** * <p>Convert a String to a double, returning a * default value if the conversion fails.</p> * * <p>If the string str is null, the default * value is returned.</p> * * <pre> * NumberUtils.toDouble(null, 1.1d) = 1.1d * NumberUtils.toDouble("", 1.1d) = 1.1d * NumberUtils.toDouble("1.5", 0.0d) = 1.5d * </pre> * * @param str the string to convert, may be <code>null * @param defaultValue the default value * @return the double represented by the string, or defaultValue * if conversion fails * @since 2.1 */ public static double toDouble(final String str, final double defaultValue) { if (str == null) { return defaultValue; } try { return Double.parseDouble(str); } catch (final NumberFormatException nfe) { return defaultValue; } } //----------------------------------------------------------------------- /** * <p>Convert a String to a byte, returning * <code>zero if the conversion fails.

* * <p>If the string is null, zero is returned.

* * <pre> * NumberUtils.toByte(null) = 0 * NumberUtils.toByte("") = 0 * NumberUtils.toByte("1") = 1 * </pre> * * @param str the string to convert, may be null * @return the byte represented by the string, or <code>zero if * conversion fails * @since 2.5 */ public static byte toByte(final String str) { return toByte(str, (byte) 0); } /** * <p>Convert a String to a byte, returning a * default value if the conversion fails.</p> * * <p>If the string is null, the default value is returned.

* * <pre> * NumberUtils.toByte(null, 1) = 1 * NumberUtils.toByte("", 1) = 1 * NumberUtils.toByte("1", 0) = 1 * </pre> * * @param str the string to convert, may be null * @param defaultValue the default value * @return the byte represented by the string, or the default if conversion fails * @since 2.5 */ public static byte toByte(final String str, final byte defaultValue) { if(str == null) { return defaultValue; } try { return Byte.parseByte(str); } catch (final NumberFormatException nfe) { return defaultValue; } } /** * <p>Convert a String to a short, returning * <code>zero if the conversion fails.

* * <p>If the string is null, zero is returned.

* * <pre> * NumberUtils.toShort(null) = 0 * NumberUtils.toShort("") = 0 * NumberUtils.toShort("1") = 1 * </pre> * * @param str the string to convert, may be null * @return the short represented by the string, or <code>zero if * conversion fails * @since 2.5 */ public static short toShort(final String str) { return toShort(str, (short) 0); } /** * <p>Convert a String to an short, returning a * default value if the conversion fails.</p> * * <p>If the string is null, the default value is returned.

* * <pre> * NumberUtils.toShort(null, 1) = 1 * NumberUtils.toShort("", 1) = 1 * NumberUtils.toShort("1", 0) = 1 * </pre> * * @param str the string to convert, may be null * @param defaultValue the default value * @return the short represented by the string, or the default if conversion fails * @since 2.5 */ public static short toShort(final String str, final short defaultValue) { if(str == null) { return defaultValue; } try { return Short.parseShort(str); } catch (final 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) // Float.valueOf(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) // Integer.valueOf(String) // Double.valueOf(String) // new Byte(String) // Long.valueOf(String) // Long.getLong(String) // Long.getLong(String,int) // Long.getLong(String,Integer) // Long.valueOf(String,int) // Long.valueOf(String) // Short.valueOf(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>If the string starts with {@code 0x} or {@code -0x} (lower or upper case) or {@code #} or {@code -#}, it * will be interpreted as a hexadecimal Integer - or Long, if the number of digits after the * prefix is more than 8 - or BigInteger if there are more than 16 digits. * </p> * <p>Then, the value is examined for a type qualifier on the end, i.e. one of * <code>'f','F','d','D','l','L'. If it is found, it starts * trying to create successively larger types from the type specified * until one is found that can represent 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 to * <code>BigInteger and from Float to * <code>BigDecimal.

* * <p> * Integral values with a leading {@code 0} will be interpreted as octal; the returned number will * be Integer, Long or BigDecimal as appropriate. * </p> * * <p>Returns null if the string is null.

* * <p>This method does not trim the input string, i.e., strings with leading * or trailing spaces will generate NumberFormatExceptions.</p> * * @param str String containing a number, may be null * @return Number created from the string (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static Number createNumber(final String str) throws NumberFormatException { if (str == null) { return null; } if (StringUtils.isBlank(str)) { throw new NumberFormatException("A blank string is not a valid number"); } // Need to deal with all possible hex prefixes here final String[] hex_prefixes = {"0x", "0X", "-0x", "-0X", "#", "-#"}; int pfxLen = 0; for(final String pfx : hex_prefixes) { if (str.startsWith(pfx)) { pfxLen += pfx.length(); break; } } if (pfxLen > 0) { // we have a hex number char firstSigDigit = 0; // strip leading zeroes for(int i = pfxLen; i < str.length(); i++) { firstSigDigit = str.charAt(i); if (firstSigDigit == '0') { // count leading zeroes pfxLen++; } else { break; } } final int hexDigits = str.length() - pfxLen; if (hexDigits > 16 || (hexDigits == 16 && firstSigDigit > '7')) { // too many for Long return createBigInteger(str); } if (hexDigits > 8 || (hexDigits == 8 && firstSigDigit > '7')) { // too many for an int return createLong(str); } return createInteger(str); } final char lastChar = str.charAt(str.length() - 1); String mant; String dec; String exp; final int decPos = str.indexOf('.'); final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present // if both e and E are present, this is caught by the checks on expPos (which prevent IOOBE) // and the parsing which will detect if e or E appear in a number due to using the wrong offset if (decPos > -1) { // there is a decimal point if (expPos > -1) { // there is an exponent if (expPos < decPos || expPos > str.length()) { // prevents double exponent causing IOOBE throw new NumberFormatException(str + " is not a valid number."); } dec = str.substring(decPos + 1, expPos); } else { dec = str.substring(decPos + 1); } mant = getMantissa(str, decPos); } else { if (expPos > -1) { if (expPos > str.length()) { // prevents double exponent causing IOOBE throw new NumberFormatException(str + " is not a valid number."); } mant = getMantissa(str, expPos); } else { mant = getMantissa(str); } dec = null; } if (!Character.isDigit(lastChar) && lastChar != '.') { if (expPos > -1 && expPos < str.length() - 1) { exp = str.substring(expPos + 1, str.length() - 1); } else { exp = null; } //Requesting a specific type.. final String numeric = str.substring(0, str.length() - 1); final boolean allZeros = isAllZeros(mant) && isAllZeros(exp); switch (lastChar) { case 'l' : case 'L' : if (dec == null && exp == null && (numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) { try { return createLong(numeric); } catch (final NumberFormatException nfe) { // NOPMD // Too big for a long } return createBigInteger(numeric); } throw new NumberFormatException(str + " is not a valid number."); case 'f' : case 'F' : try { final Float f = NumberUtils.createFloat(str); 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 does not have the precision we want return f; } } catch (final NumberFormatException nfe) { // NOPMD // ignore the bad number } //$FALL-THROUGH$ case 'd' : case 'D' : try { final Double d = NumberUtils.createDouble(str); if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) { return d; } } catch (final NumberFormatException nfe) { // NOPMD // ignore the bad number } try { return createBigDecimal(numeric); } catch (final NumberFormatException e) { // NOPMD // ignore the bad number } //$FALL-THROUGH$ default : throw new NumberFormatException(str + " is not a valid number."); } } //User doesn't have a preference on the return type, so let's start //small and go from there... if (expPos > -1 && expPos < str.length() - 1) { exp = str.substring(expPos + 1, str.length()); } else { exp = null; } if (dec == null && exp == null) { // no decimal point and no exponent //Must be an Integer, Long, Biginteger try { return createInteger(str); } catch (final NumberFormatException nfe) { // NOPMD // ignore the bad number } try { return createLong(str); } catch (final NumberFormatException nfe) { // NOPMD // ignore the bad number } return createBigInteger(str); } //Must be a Float, Double, BigDecimal final boolean allZeros = isAllZeros(mant) && isAllZeros(exp); try { final Float f = createFloat(str); final Double d = createDouble(str); if (!f.isInfinite() && !(f.floatValue() == 0.0F && !allZeros) && f.toString().equals(d.toString())) { return f; } if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !allZeros)) { final BigDecimal b = createBigDecimal(str); if (b.compareTo(BigDecimal.valueOf(d)) == 0) { return d; } return b; } } catch (final NumberFormatException nfe) { // NOPMD // ignore the bad number } return createBigDecimal(str); } /** * <p>Utility method for {@link #createNumber(java.lang.String)}.

* * <p>Returns mantissa of the given number.

* * @param str the string representation of the number * @return mantissa of the given number */ private static String getMantissa(final String str) { return getMantissa(str, str.length()); } /** * <p>Utility method for {@link #createNumber(java.lang.String)}.

* * <p>Returns mantissa of the given number.

* * @param str the string representation of the number * @param stopPos the position of the exponent or decimal point * @return mantissa of the given number */ private static String getMantissa(final String str, final int stopPos) { final char firstChar = str.charAt(0); final boolean hasSign = (firstChar == '-' || firstChar == '+'); return hasSign ? str.substring(1, stopPos) : str.substring(0, stopPos); } /** * <p>Utility method for {@link #createNumber(java.lang.String)}.

* * <p>Returns true if s is null.

* * @param str the String to check * @return if it is all zeros or <code>null */ private static boolean isAllZeros(final String str) { if (str == null) { return true; } for (int i = str.length() - 1; i >= 0; i--) { if (str.charAt(i) != '0') { return false; } } return str.length() > 0; } //----------------------------------------------------------------------- /** * <p>Convert a String to a Float.

* * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>Float (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static Float createFloat(final String str) { if (str == null) { return null; } return Float.valueOf(str); } /** * <p>Convert a String to a Double.

* * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>Double (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static Double createDouble(final String str) { if (str == null) { return null; } return Double.valueOf(str); } /** * <p>Convert a String to a Integer, handling * hex (0xhhhh) and octal (0dddd) notations. * N.B. a leading zero means octal; spaces are not trimmed.</p> * * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>Integer (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static Integer createInteger(final String str) { if (str == null) { return null; } // decode() handles 0xAABD and 0777 (hex and octal) as well. return Integer.decode(str); } /** * <p>Convert a String to a Long; * since 3.1 it handles hex (0Xhhhh) and octal (0ddd) notations. * N.B. a leading zero means octal; spaces are not trimmed.</p> * * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>Long (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static Long createLong(final String str) { if (str == null) { return null; } return Long.decode(str); } /** * <p>Convert a String to a BigInteger; * since 3.2 it handles hex (0x or #) and octal (0) notations.</p> * * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>BigInteger (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static BigInteger createBigInteger(final String str) { if (str == null) { return null; } int pos = 0; // offset within string int radix = 10; boolean negate = false; // need to negate later? if (str.startsWith("-")) { negate = true; pos = 1; } if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex radix = 16; pos += 2; } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer) radix = 16; pos ++; } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits radix = 8; pos ++; } // default is to treat as decimal final BigInteger value = new BigInteger(str.substring(pos), radix); return negate ? value.negate() : value; } /** * <p>Convert a String to a BigDecimal.

* * <p>Returns null if the string is null.

* * @param str a <code>String to convert, may be null * @return converted <code>BigDecimal (or null if the input is null) * @throws NumberFormatException if the value cannot be converted */ public static BigDecimal createBigDecimal(final String str) { if (str == null) { return null; } // handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException if (StringUtils.isBlank(str)) { throw new NumberFormatException("A blank string is not a valid number"); } if (str.trim().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. throw new NumberFormatException(str + " is not a valid number."); } return new BigDecimal(str); } // Min in array //-------------------------------------------------------------------- /** * <p>Returns the minimum value in an array.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from min(long[]) to min(long...) */ public static long min(final long... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from min(int[]) to min(int...) */ public static int min(final int... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from min(short[]) to min(short...) */ public static short min(final short... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from min(byte[]) to min(byte...) */ public static byte min(final byte... array) { // Validates input validateArray(array); // Finds and returns min byte 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.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method that handles NaN differently * @since 3.4 Changed signature from min(double[]) to min(double...) */ public static double min(final double... array) { // Validates input validateArray(array); // Finds and returns min double min = array[0]; for (int i = 1; i < array.length; i++) { if (Double.isNaN(array[i])) { return Double.NaN; } if (array[i] < min) { min = array[i]; } } return min; } /** * <p>Returns the minimum value in an array.

* * @param array an array, must not be null or empty * @return the minimum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method that handles NaN differently * @since 3.4 Changed signature from min(float[]) to min(float...) */ public static float min(final float... array) { // Validates input validateArray(array); // Finds and returns min float min = array[0]; for (int i = 1; i < array.length; i++) { if (Float.isNaN(array[i])) { return Float.NaN; } if (array[i] < min) { min = array[i]; } } return min; } // Max in array //-------------------------------------------------------------------- /** * <p>Returns the maximum value in an array.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from max(long[]) to max(long...) */ public static long max(final long... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from max(int[]) to max(int...) */ public static int max(final int... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from max(short[]) to max(short...) */ public static short max(final short... array) { // Validates input validateArray(array); // 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.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @since 3.4 Changed signature from max(byte[]) to max(byte...) */ public static byte max(final byte... array) { // Validates input validateArray(array); // Finds and returns max byte 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.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method that handles NaN differently * @since 3.4 Changed signature from max(double[]) to max(double...) */ public static double max(final double... array) { // Validates input validateArray(array); // Finds and returns max double max = array[0]; for (int j = 1; j < array.length; j++) { if (Double.isNaN(array[j])) { return Double.NaN; } if (array[j] > max) { max = array[j]; } } return max; } /** * <p>Returns the maximum value in an array.

* * @param array an array, must not be null or empty * @return the maximum value in the array * @throws IllegalArgumentException if <code>array is null * @throws IllegalArgumentException if <code>array is empty * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method that handles NaN differently * @since 3.4 Changed signature from max(float[]) to max(float...) */ public static float max(final float... array) { // Validates input validateArray(array); // Finds and returns max float max = array[0]; for (int j = 1; j < array.length; j++) { if (Float.isNaN(array[j])) { return Float.NaN; } if (array[j] > max) { max = array[j]; } } return max; } /** * Checks if the specified array is neither null nor empty. * * @param array the array to check * @throws IllegalArgumentException if {@code array} is either {@code null} or empty */ private static void validateArray(final Object array) { if (array == null) { throw new IllegalArgumentException("The Array must not be null"); } Validate.isTrue(Array.getLength(array) != 0, "Array cannot be empty."); } // 3 param min //----------------------------------------------------------------------- /** * <p>Gets the minimum of three long values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values */ public static long min(long a, final long b, final long c) { if (b < a) { a = b; } if (c < a) { a = c; } return a; } /** * <p>Gets the minimum of three int values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values */ public static int min(int a, final int b, final int c) { if (b < a) { a = b; } if (c < a) { a = c; } return a; } /** * <p>Gets the minimum of three short values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values */ public static short min(short a, final short b, final short c) { if (b < a) { a = b; } if (c < a) { a = c; } return a; } /** * <p>Gets the minimum of three byte values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values */ public static byte min(byte a, final byte b, final byte c) { if (b < a) { a = b; } if (c < a) { a = c; } return a; } /** * <p>Gets the minimum of three double values.

* * <p>If any value is NaN, NaN is * returned. Infinity is handled.</p> * * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values * @see IEEE754rUtils#min(double, double, double) for a version of this method that handles NaN differently */ public static double min(final double a, final double b, final double c) { return Math.min(Math.min(a, b), c); } /** * <p>Gets the minimum of three float values.

* * <p>If any value is NaN, NaN is * returned. Infinity is handled.</p> * * @param a value 1 * @param b value 2 * @param c value 3 * @return the smallest of the values * @see IEEE754rUtils#min(float, float, float) for a version of this method that handles NaN differently */ public static float min(final float a, final float b, final float c) { return Math.min(Math.min(a, b), c); } // 3 param max //----------------------------------------------------------------------- /** * <p>Gets the maximum of three long values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values */ public static long max(long a, final long b, final long c) { if (b > a) { a = b; } if (c > a) { a = c; } return a; } /** * <p>Gets the maximum of three int values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values */ public static int max(int a, final int b, final int c) { if (b > a) { a = b; } if (c > a) { a = c; } return a; } /** * <p>Gets the maximum of three short values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values */ public static short max(short a, final short b, final short c) { if (b > a) { a = b; } if (c > a) { a = c; } return a; } /** * <p>Gets the maximum of three byte values.

* * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values */ public static byte max(byte a, final byte b, final byte c) { if (b > a) { a = b; } if (c > a) { a = c; } return a; } /** * <p>Gets the maximum of three double values.

* * <p>If any value is NaN, NaN is * returned. Infinity is handled.</p> * * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values * @see IEEE754rUtils#max(double, double, double) for a version of this method that handles NaN differently */ public static double max(final double a, final double b, final double c) { return Math.max(Math.max(a, b), c); } /** * <p>Gets the maximum of three float values.

* * <p>If any value is NaN, NaN is * returned. Infinity is handled.</p> * * @param a value 1 * @param b value 2 * @param c value 3 * @return the largest of the values * @see IEEE754rUtils#max(float, float, float) for a version of this method that handles NaN differently */ public static float max(final float a, final float b, final float c) { return Math.max(Math.max(a, b), c); } //----------------------------------------------------------------------- /** * <p>Checks whether the String contains only * digit characters.</p> * * <p>Null and empty String will return * <code>false.

* * @param str the <code>String to check * @return <code>true if str contains only Unicode numeric */ public static boolean isDigits(final String str) { return StringUtils.isNumeric(str); } /** * <p>Checks whether the String a valid Java number.

* * <p>Valid numbers include hexadecimal marked with the 0x or * <code>0X qualifier, octal numbers, scientific notation and numbers * marked with a type qualifier (e.g. 123L).</p> * * <p>Non-hexadecimal strings beginning with a leading zero are * treated as octal values. Thus the string <code>09 will return * <code>false, since 9 is not a valid octal value. * However, numbers beginning with {@code 0.} are treated as decimal.</p> * * <p>null and empty/blank {@code String} will return * <code>false.

* * @param str the <code>String to check * @return <code>true if the string is a correctly formatted number * @since 3.3 the code supports hex {@code 0Xhhh} and octal {@code 0ddd} validation */ public static boolean isNumber(final String str) { if (StringUtils.isEmpty(str)) { return false; } final 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 final int start = (chars[0] == '-') ? 1 : 0; if (sz > start + 1 && chars[start] == '0') { // leading 0 if ( (chars[start + 1] == 'x') || (chars[start + 1] == 'X') ) { // leading 0x/0X 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; } else if (Character.isDigit(chars[start + 1])) { // leading 0, but not hex, must be octal int i = start + 1; for (; i < chars.length; i++) { if (chars[i] < '0' || chars[i] > '7') { 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 (chars[i] == '.') { if (hasDecPoint || hasExp) { // two decimal points or dec in exponent return false; } // single trailing decimal point after non-exponent is ok return foundDigit; } 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 exponent or decimal point return foundDigit && !hasExp && !hasDecPoint; } // 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; } /** * <p>Checks whether the given String is a parsable number.

* * <p>Parsable numbers include those Strings understood by {@link Integer#parseInt(String)}, * {@link Long#parseLong(String)}, {@link Float#parseFloat(String)} or * {@link Double#parseDouble(String)}. This method can be used instead of catching {@link java.text.ParseException} * when calling one of those methods.</p> * * <p>Hexadecimal and scientific notations are not considered parsable. * See {@link #isNumber(String)} on those cases.</p> * * <p>{@code Null} and empty String will return false.

* * @param str the String to check. * @return {@code true} if the string is a parsable number. * @since 3.4 */ public static boolean isParsable(final String str) { if (StringUtils.isEmpty(str)) { return false; } if (str.charAt(str.length() - 1) == '.') { return false; } if (str.charAt(0) == '-') { if (str.length() == 1) { return false; } return withDecimalsParsing(str, 1); } else { return withDecimalsParsing(str, 0); } } private static boolean withDecimalsParsing(final String str, final int beginIdx) { int decimalPoints = 0; for (int i = beginIdx; i < str.length(); i++) { final boolean isDecimalPoint = str.charAt(i) == '.'; if (isDecimalPoint) { decimalPoints++; } if (decimalPoints > 1) { return false; } if (!isDecimalPoint && !Character.isDigit(str.charAt(i))) { return false; } } return true; } /** * <p>Compares two {@code int} values numerically. This is the same functionality as provided in Java 7.

* * @param x the first {@code int} to compare * @param y the second {@code int} to compare * @return the value {@code 0} if {@code x == y}; * a value less than {@code 0} if {@code x < y}; and * a value greater than {@code 0} if {@code x > y} * @since 3.4 */ public static int compare(int x, int y) { if (x == y) { return 0; } return x < y ? -1 : 1; } /** * <p>Compares to {@code long} values numerically. This is the same functionality as provided in Java 7.

* * @param x the first {@code long} to compare * @param y the second {@code long} to compare * @return the value {@code 0} if {@code x == y}; * a value less than {@code 0} if {@code x < y}; and * a value greater than {@code 0} if {@code x > y} * @since 3.4 */ public static int compare(long x, long y) { if (x == y) { return 0; } return x < y ? -1 : 1; } /** * <p>Compares to {@code short} values numerically. This is the same functionality as provided in Java 7.

* * @param x the first {@code short} to compare * @param y the second {@code short} to compare * @return the value {@code 0} if {@code x == y}; * a value less than {@code 0} if {@code x < y}; and * a value greater than {@code 0} if {@code x > y} * @since 3.4 */ public static int compare(short x, short y) { if (x == y) { return 0; } return x < y ? -1 : 1; } /** * <p>Compares two {@code byte} values numerically. This is the same functionality as provided in Java 7.

* * @param x the first {@code byte} to compare * @param y the second {@code byte} to compare * @return the value {@code 0} if {@code x == y}; * a value less than {@code 0} if {@code x < y}; and * a value greater than {@code 0} if {@code x > y} * @since 3.4 */ public static int compare(byte x, byte y) { return x - y; } }

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