Class NumberUtils


  • public class NumberUtils
    extends Object

    Provides extra functionality for Java Number classes.

    Since:
    2.0
    Version:
    $Id: NumberUtils.java 1056853 2011-01-09 01:07:04Z niallp $
    • Constructor Summary

      Constructors 
      Constructor Description
      NumberUtils()
      NumberUtils instances should NOT be constructed in standard programming.
    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static int compare​(double lhs, double rhs)
      Compares two doubles for order.
      static int compare​(float lhs, float rhs)
      Compares two floats for order.
      static BigDecimal createBigDecimal​(String str)
      Convert a String to a BigDecimal.
      static BigInteger createBigInteger​(String str)
      Convert a String to a BigInteger.
      static Double createDouble​(String str)
      Convert a String to a Double.
      static Float createFloat​(String str)
      Convert a String to a Float.
      static Integer createInteger​(String str)
      Convert a String to a Integer, handling hex and octal notations.
      static Long createLong​(String str)
      Convert a String to a Long.
      static Number createNumber​(String str)
      Turns a string value into a java.lang.Number.
      static boolean isDigits​(String str)
      Checks whether the String contains only digit characters.
      static boolean isNumber​(String str)
      Checks whether the String a valid Java number.
      static byte max​(byte[] array)
      Returns the maximum value in an array.
      static byte max​(byte a, byte b, byte c)
      Gets the maximum of three byte values.
      static double max​(double[] array)
      Returns the maximum value in an array.
      static double max​(double a, double b, double c)
      Gets the maximum of three double values.
      static float max​(float[] array)
      Returns the maximum value in an array.
      static float max​(float a, float b, float c)
      Gets the maximum of three float values.
      static int max​(int[] array)
      Returns the maximum value in an array.
      static int max​(int a, int b, int c)
      Gets the maximum of three int values.
      static long max​(long[] array)
      Returns the maximum value in an array.
      static long max​(long a, long b, long c)
      Gets the maximum of three long values.
      static short max​(short[] array)
      Returns the maximum value in an array.
      static short max​(short a, short b, short c)
      Gets the maximum of three short values.
      static byte min​(byte[] array)
      Returns the minimum value in an array.
      static byte min​(byte a, byte b, byte c)
      Gets the minimum of three byte values.
      static double min​(double[] array)
      Returns the minimum value in an array.
      static double min​(double a, double b, double c)
      Gets the minimum of three double values.
      static float min​(float[] array)
      Returns the minimum value in an array.
      static float min​(float a, float b, float c)
      Gets the minimum of three float values.
      static int min​(int[] array)
      Returns the minimum value in an array.
      static int min​(int a, int b, int c)
      Gets the minimum of three int values.
      static long min​(long[] array)
      Returns the minimum value in an array.
      static long min​(long a, long b, long c)
      Gets the minimum of three long values.
      static short min​(short[] array)
      Returns the minimum value in an array.
      static short min​(short a, short b, short c)
      Gets the minimum of three short values.
      static int stringToInt​(String str)
      Deprecated.
      Use toInt(String) This method will be removed in Commons Lang 3.0
      static int stringToInt​(String str, int defaultValue)
      Deprecated.
      Use toInt(String, int) This method will be removed in Commons Lang 3.0
      static byte toByte​(String str)
      Convert a String to a byte, returning zero if the conversion fails.
      static byte toByte​(String str, byte defaultValue)
      Convert a String to a byte, returning a default value if the conversion fails.
      static double toDouble​(String str)
      Convert a String to a double, returning 0.0d if the conversion fails.
      static double toDouble​(String str, double defaultValue)
      Convert a String to a double, returning a default value if the conversion fails.
      static float toFloat​(String str)
      Convert a String to a float, returning 0.0f if the conversion fails.
      static float toFloat​(String str, float defaultValue)
      Convert a String to a float, returning a default value if the conversion fails.
      static int toInt​(String str)
      Convert a String to an int, returning zero if the conversion fails.
      static int toInt​(String str, int defaultValue)
      Convert a String to an int, returning a default value if the conversion fails.
      static long toLong​(String str)
      Convert a String to a long, returning zero if the conversion fails.
      static long toLong​(String str, long defaultValue)
      Convert a String to a long, returning a default value if the conversion fails.
      static short toShort​(String str)
      Convert a String to a short, returning zero if the conversion fails.
      static short toShort​(String str, short defaultValue)
      Convert a String to an short, returning a default value if the conversion fails.
    • Field Detail

      • LONG_ZERO

        public static final Long LONG_ZERO
        Reusable Long constant for zero.
      • LONG_ONE

        public static final Long LONG_ONE
        Reusable Long constant for one.
      • LONG_MINUS_ONE

        public static final Long LONG_MINUS_ONE
        Reusable Long constant for minus one.
      • INTEGER_ZERO

        public static final Integer INTEGER_ZERO
        Reusable Integer constant for zero.
      • INTEGER_ONE

        public static final Integer INTEGER_ONE
        Reusable Integer constant for one.
      • INTEGER_MINUS_ONE

        public static final Integer INTEGER_MINUS_ONE
        Reusable Integer constant for minus one.
      • SHORT_ZERO

        public static final Short SHORT_ZERO
        Reusable Short constant for zero.
      • SHORT_ONE

        public static final Short SHORT_ONE
        Reusable Short constant for one.
      • SHORT_MINUS_ONE

        public static final Short SHORT_MINUS_ONE
        Reusable Short constant for minus one.
      • BYTE_ZERO

        public static final Byte BYTE_ZERO
        Reusable Byte constant for zero.
      • BYTE_ONE

        public static final Byte BYTE_ONE
        Reusable Byte constant for one.
      • BYTE_MINUS_ONE

        public static final Byte BYTE_MINUS_ONE
        Reusable Byte constant for minus one.
      • DOUBLE_ZERO

        public static final Double DOUBLE_ZERO
        Reusable Double constant for zero.
      • DOUBLE_ONE

        public static final Double DOUBLE_ONE
        Reusable Double constant for one.
      • DOUBLE_MINUS_ONE

        public static final Double DOUBLE_MINUS_ONE
        Reusable Double constant for minus one.
      • FLOAT_ZERO

        public static final Float FLOAT_ZERO
        Reusable Float constant for zero.
      • FLOAT_ONE

        public static final Float FLOAT_ONE
        Reusable Float constant for one.
      • FLOAT_MINUS_ONE

        public static final Float FLOAT_MINUS_ONE
        Reusable Float constant for minus one.
    • Constructor Detail

      • NumberUtils

        public NumberUtils()

        NumberUtils instances should NOT be constructed in standard programming. Instead, the class should be used as NumberUtils.toInt("6");.

        This constructor is public to permit tools that require a JavaBean instance to operate.

    • Method Detail

      • stringToInt

        public static int stringToInt​(String str)
        Deprecated.
        Use toInt(String) This method will be removed in Commons Lang 3.0

        Convert a String to an int, returning zero if the conversion fails.

        If the string is null, zero is returned.

           NumberUtils.stringToInt(null) = 0
           NumberUtils.stringToInt("")   = 0
           NumberUtils.stringToInt("1")  = 1
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the int represented by the string, or zero if conversion fails
      • toInt

        public static int toInt​(String str)

        Convert a String to an int, returning zero if the conversion fails.

        If the string is null, zero is returned.

           NumberUtils.toInt(null) = 0
           NumberUtils.toInt("")   = 0
           NumberUtils.toInt("1")  = 1
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the int represented by the string, or zero if conversion fails
        Since:
        2.1
      • stringToInt

        public static int stringToInt​(String str,
                                      int defaultValue)
        Deprecated.
        Use toInt(String, int) This method will be removed in Commons Lang 3.0

        Convert a String to an int, returning a default value if the conversion fails.

        If the string is null, the default value is returned.

           NumberUtils.stringToInt(null, 1) = 1
           NumberUtils.stringToInt("", 1)   = 1
           NumberUtils.stringToInt("1", 0)  = 1
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the int represented by the string, or the default if conversion fails
      • toInt

        public static int toInt​(String str,
                                int defaultValue)

        Convert a String to an int, returning a default value if the conversion fails.

        If the string is null, the default value is returned.

           NumberUtils.toInt(null, 1) = 1
           NumberUtils.toInt("", 1)   = 1
           NumberUtils.toInt("1", 0)  = 1
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the int represented by the string, or the default if conversion fails
        Since:
        2.1
      • toLong

        public static long toLong​(String str)

        Convert a String to a long, returning zero if the conversion fails.

        If the string is null, zero is returned.

           NumberUtils.toLong(null) = 0L
           NumberUtils.toLong("")   = 0L
           NumberUtils.toLong("1")  = 1L
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the long represented by the string, or 0 if conversion fails
        Since:
        2.1
      • toLong

        public static long toLong​(String str,
                                  long defaultValue)

        Convert a String to a long, returning a default value if the conversion fails.

        If the string is null, the default value is returned.

           NumberUtils.toLong(null, 1L) = 1L
           NumberUtils.toLong("", 1L)   = 1L
           NumberUtils.toLong("1", 0L)  = 1L
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the long represented by the string, or the default if conversion fails
        Since:
        2.1
      • toFloat

        public static float toFloat​(String str)

        Convert a String to a float, returning 0.0f if the conversion fails.

        If the string str is null, 0.0f is returned.

           NumberUtils.toFloat(null)   = 0.0f
           NumberUtils.toFloat("")     = 0.0f
           NumberUtils.toFloat("1.5")  = 1.5f
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the float represented by the string, or 0.0f if conversion fails
        Since:
        2.1
      • toFloat

        public static float toFloat​(String str,
                                    float defaultValue)

        Convert a String to a float, returning a default value if the conversion fails.

        If the string str is null, the default value is returned.

           NumberUtils.toFloat(null, 1.1f)   = 1.0f
           NumberUtils.toFloat("", 1.1f)     = 1.1f
           NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the float represented by the string, or defaultValue if conversion fails
        Since:
        2.1
      • toDouble

        public static double toDouble​(String str)

        Convert a String to a double, returning 0.0d if the conversion fails.

        If the string str is null, 0.0d is returned.

           NumberUtils.toDouble(null)   = 0.0d
           NumberUtils.toDouble("")     = 0.0d
           NumberUtils.toDouble("1.5")  = 1.5d
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the double represented by the string, or 0.0d if conversion fails
        Since:
        2.1
      • toDouble

        public static double toDouble​(String str,
                                      double defaultValue)

        Convert a String to a double, returning a default value if the conversion fails.

        If the string str is null, the default value is returned.

           NumberUtils.toDouble(null, 1.1d)   = 1.1d
           NumberUtils.toDouble("", 1.1d)     = 1.1d
           NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the double represented by the string, or defaultValue if conversion fails
        Since:
        2.1
      • toByte

        public static byte toByte​(String str)

        Convert a String to a byte, returning zero if the conversion fails.

        If the string is null, zero is returned.

           NumberUtils.toByte(null) = 0
           NumberUtils.toByte("")   = 0
           NumberUtils.toByte("1")  = 1
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the byte represented by the string, or zero if conversion fails
        Since:
        2.5
      • toByte

        public static byte toByte​(String str,
                                  byte defaultValue)

        Convert a String to a byte, returning a default value if the conversion fails.

        If the string is null, the default value is returned.

           NumberUtils.toByte(null, 1) = 1
           NumberUtils.toByte("", 1)   = 1
           NumberUtils.toByte("1", 0)  = 1
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the byte represented by the string, or the default if conversion fails
        Since:
        2.5
      • toShort

        public static short toShort​(String str)

        Convert a String to a short, returning zero if the conversion fails.

        If the string is null, zero is returned.

           NumberUtils.toShort(null) = 0
           NumberUtils.toShort("")   = 0
           NumberUtils.toShort("1")  = 1
         
        Parameters:
        str - the string to convert, may be null
        Returns:
        the short represented by the string, or zero if conversion fails
        Since:
        2.5
      • toShort

        public static short toShort​(String str,
                                    short defaultValue)

        Convert a String to an short, returning a default value if the conversion fails.

        If the string is null, the default value is returned.

           NumberUtils.toShort(null, 1) = 1
           NumberUtils.toShort("", 1)   = 1
           NumberUtils.toShort("1", 0)  = 1
         
        Parameters:
        str - the string to convert, may be null
        defaultValue - the default value
        Returns:
        the short represented by the string, or the default if conversion fails
        Since:
        2.5
      • createNumber

        public static Number createNumber​(String str)
                                   throws NumberFormatException

        Turns a string value into a java.lang.Number.

        First, the value is examined for a type qualifier on the end ('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.

        If a type specifier is not found, it will check for a decimal point and then try successively larger types from Integer to BigInteger and from Float to BigDecimal.

        If the string starts with 0x or -0x, it will be interpreted as a hexadecimal integer. Values with leading 0's will not be interpreted as octal.

        Returns null if the string is null.

        This method does not trim the input string, i.e., strings with leading or trailing spaces will generate NumberFormatExceptions.

        Parameters:
        str - String containing a number, may be null
        Returns:
        Number created from the string
        Throws:
        NumberFormatException - if the value cannot be converted
      • createFloat

        public static Float createFloat​(String str)

        Convert a String to a Float.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted Float
        Throws:
        NumberFormatException - if the value cannot be converted
      • createDouble

        public static Double createDouble​(String str)

        Convert a String to a Double.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted Double
        Throws:
        NumberFormatException - if the value cannot be converted
      • createInteger

        public static Integer createInteger​(String str)

        Convert a String to a Integer, handling hex and octal notations.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted Integer
        Throws:
        NumberFormatException - if the value cannot be converted
      • createLong

        public static Long createLong​(String str)

        Convert a String to a Long.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted Long
        Throws:
        NumberFormatException - if the value cannot be converted
      • createBigInteger

        public static BigInteger createBigInteger​(String str)

        Convert a String to a BigInteger.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted BigInteger
        Throws:
        NumberFormatException - if the value cannot be converted
      • createBigDecimal

        public static BigDecimal createBigDecimal​(String str)

        Convert a String to a BigDecimal.

        Returns null if the string is null.

        Parameters:
        str - a String to convert, may be null
        Returns:
        converted BigDecimal
        Throws:
        NumberFormatException - if the value cannot be converted
      • min

        public static long min​(long[] array)

        Returns the minimum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • min

        public static int min​(int[] array)

        Returns the minimum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • min

        public static short min​(short[] array)

        Returns the minimum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • min

        public static byte min​(byte[] array)

        Returns the minimum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • max

        public static long max​(long[] array)

        Returns the maximum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • max

        public static int max​(int[] array)

        Returns the maximum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • max

        public static short max​(short[] array)

        Returns the maximum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • max

        public static byte max​(byte[] array)

        Returns the maximum value in an array.

        Parameters:
        array - an array, must not be null or empty
        Returns:
        the minimum value in the array
        Throws:
        IllegalArgumentException - if array is null
        IllegalArgumentException - if array is empty
      • min

        public static long min​(long a,
                               long b,
                               long c)

        Gets the minimum of three long values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
      • min

        public static int min​(int a,
                              int b,
                              int c)

        Gets the minimum of three int values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
      • min

        public static short min​(short a,
                                short b,
                                short c)

        Gets the minimum of three short values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
      • min

        public static byte min​(byte a,
                               byte b,
                               byte c)

        Gets the minimum of three byte values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
      • min

        public static double min​(double a,
                                 double b,
                                 double c)

        Gets the minimum of three double values.

        If any value is NaN, NaN is returned. Infinity is handled.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
        See Also:
        for a version of this method that handles NaN differently
      • min

        public static float min​(float a,
                                float b,
                                float c)

        Gets the minimum of three float values.

        If any value is NaN, NaN is returned. Infinity is handled.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the smallest of the values
        See Also:
        for a version of this method that handles NaN differently
      • max

        public static long max​(long a,
                               long b,
                               long c)

        Gets the maximum of three long values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
      • max

        public static int max​(int a,
                              int b,
                              int c)

        Gets the maximum of three int values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
      • max

        public static short max​(short a,
                                short b,
                                short c)

        Gets the maximum of three short values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
      • max

        public static byte max​(byte a,
                               byte b,
                               byte c)

        Gets the maximum of three byte values.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
      • max

        public static double max​(double a,
                                 double b,
                                 double c)

        Gets the maximum of three double values.

        If any value is NaN, NaN is returned. Infinity is handled.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
        See Also:
        for a version of this method that handles NaN differently
      • max

        public static float max​(float a,
                                float b,
                                float c)

        Gets the maximum of three float values.

        If any value is NaN, NaN is returned. Infinity is handled.

        Parameters:
        a - value 1
        b - value 2
        c - value 3
        Returns:
        the largest of the values
        See Also:
        for a version of this method that handles NaN differently
      • compare

        public static int compare​(double lhs,
                                  double rhs)

        Compares two doubles for order.

        This method is more comprehensive than the standard Java greater than, less than and equals operators.

        • It returns -1 if the first value is less than the second.
        • It returns +1 if the first value is greater than the second.
        • It returns 0 if the values are equal.

        The ordering is as follows, largest to smallest:

        • NaN
        • Positive infinity
        • Maximum double
        • Normal positive numbers
        • +0.0
        • -0.0
        • Normal negative numbers
        • Minimum double (-Double.MAX_VALUE)
        • Negative infinity

        Comparing NaN with NaN will return 0.

        Parameters:
        lhs - the first double
        rhs - the second double
        Returns:
        -1 if lhs is less, +1 if greater, 0 if equal to rhs
      • compare

        public static int compare​(float lhs,
                                  float rhs)

        Compares two floats for order.

        This method is more comprehensive than the standard Java greater than, less than and equals operators.

        • It returns -1 if the first value is less than the second.
        • It returns +1 if the first value is greater than the second.
        • It returns 0 if the values are equal.

        The ordering is as follows, largest to smallest:

        • NaN
        • Positive infinity
        • Maximum float
        • Normal positive numbers
        • +0.0
        • -0.0
        • Normal negative numbers
        • Minimum float (-Float.MAX_VALUE)
        • Negative infinity

        Comparing NaN with NaN will return 0.

        Parameters:
        lhs - the first float
        rhs - the second float
        Returns:
        -1 if lhs is less, +1 if greater, 0 if equal to rhs
      • isDigits

        public static boolean isDigits​(String str)

        Checks whether the String contains only digit characters.

        Null and empty String will return false.

        Parameters:
        str - the String to check
        Returns:
        true if str contains only unicode numeric
      • isNumber

        public static boolean isNumber​(String str)

        Checks whether the String a valid Java number.

        Valid numbers include hexadecimal marked with the 0x qualifier, scientific notation and numbers marked with a type qualifier (e.g. 123L).

        Null and empty String will return false.

        Parameters:
        str - the String to check
        Returns:
        true if the string is a correctly formatted number