Package alpine.common.util

Class ByteFormat

java.lang.Object
alpine.common.util.ByteFormat
public class ByteFormat extends Object
Class to render a byte count as a human-readable string such as "1 KB" or "1 GB" instead of a raw number such as "1024" or "1073741824". See format method for examples. Note that the human-readable values are rendered in a rough way (e.g. if it is a little over a KB we call it a KB). Use the format2() methods to display the exact byte count after the human-readable rough count.


This class does not extend the JDK Format class because the idea was to KISS!
Since:
1.0.0
Author:
Steve Springett

  • Constructor Summary

    Constructors
    Constructor
    Description
    ByteFormat()
    Construct a ByteFormat() instance with the default names[] array and min/max fraction digits.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    format(int count)
    Given a raw byte count such as 1024 or 1048576, format it in human-readable form such as "1 KB" or "1 GB".
    String
    format(long count)
    Same as format(int), but accepts a long.
    String
    format2(int count)
    Similar to format(int), but the raw byte count is placed in parentheses following the formatted value (if the value is greater than 1023 bytes).
    String
    format2(long count)
    Similar to format(long), but the raw byte count is placed in parentheses following the formatted value (if the value is greater than 1023 bytes).
    ByteFormat
    maximumFractionDigits(int d)
    Set the maximum number of fraction digits.
    ByteFormat
    minimumFractionDigits(int d)
    Set the minimum number of fraction digits.
    ByteFormat
    names(String[] names)
    Set the names[] array to something other than the default one (see constructor).
    void
    setMaximumFractionDigits(int d)
    Set the maximum number of fraction digits.
    void
    setMinimumFractionDigits(int d)
    Set the minimum number of fraction digits.
    void
    setNames(String[] names)
    Set the names[] array to something other than the default one (see constructor).

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • ByteFormat

      public ByteFormat()
      Construct a ByteFormat() instance with the default names[] array and min/max fraction digits.
      Since:
      1.0.0

  • Method Details

    • format

      public String format(int count)
      Given a raw byte count such as 1024 or 1048576, format it in human-readable form such as "1 KB" or "1 GB".


      Here are some example results using the default min/max values for fraction digits:


      0 - 0 bytes 1 - 1 byte 1023 - 1,023 bytes 1024 (1 KB) - 1 KB 1025 - 1 KB 2000 - 2 KB 1048575 - 1,024 KB 1048576 (1 MB) - 1 MB 1048577 - 1 MB 5000000 - 4.8 MB 1073741824 (1 GB) - 1 GB
      Parameters:
      count - int
      Returns:
      String
      Throws:
      NumberFormatException - Thrown if specified count is less than 0.
      Since:
      1.0.0

    • format2

      public String format2(int count)
      Similar to format(int), but the raw byte count is placed in parentheses following the formatted value (if the value is greater than 1023 bytes). e.g.:


      1023 - 1,023 bytes 1025 - 1 KB (1025 bytes)
      Parameters:
      count - int
      Returns:
      String
      Since:
      1.0.0

    • format

      public String format(long count)
      Same as format(int), but accepts a long. Note that the maximum unit this class can deal with is gigabytes, so if the specified count is very large it will still be expressed in terms of gigabytes, e.g. "5,000,000 GB".


      Example results:
       format(Integer.MAX_VALUE + 1L)   - 2 GB
 format(Long.MAX_VALUE)           - 8,589,934,592 GB
      Parameters:
      count - int
      Returns:
      String
      Since:
      1.0.0

    • format2

      public String format2(long count)
      Similar to format(long), but the raw byte count is placed in parentheses following the formatted value (if the value is greater than 1023 bytes). e.g.:
       1023 - 1,023 bytes
 1025 - 1 KB (1025 bytes)
      Parameters:
      count - int
      Returns:
      String
      Since:
      1.0.0

    • setMinimumFractionDigits

      public void setMinimumFractionDigits(int d)
      Set the minimum number of fraction digits. (See constructor for default.)
      Parameters:
      d - int
      Since:
      1.0.0

    • minimumFractionDigits

      public ByteFormat minimumFractionDigits(int d)
      Set the minimum number of fraction digits. (See constructor for default.)
      Parameters:
      d - int
      Since:
      1.9.0

    • setMaximumFractionDigits

      public void setMaximumFractionDigits(int d)
      Set the maximum number of fraction digits. (See constructor for default.)
      Parameters:
      d - int
      Since:
      1.0.0

    • maximumFractionDigits

      public ByteFormat maximumFractionDigits(int d)
      Set the maximum number of fraction digits. (See constructor for default.)
      Parameters:
      d - int
      Since:
      1.9.0

    • setNames

      public void setNames(String[] names)
      Set the names[] array to something other than the default one (see constructor). You could do this, for example, if you wanted to spell out "gigabytes" instead of using "GB". Note: The new array must be the same size as the original. (There is no error checking to enforce this.)
      Parameters:
      names - String[]
      Since:
      1.0.0

    • names

      public ByteFormat names(String[] names)
      Set the names[] array to something other than the default one (see constructor). You could do this, for example, if you wanted to spell out "gigabytes" instead of using "GB". Note: The new array must be the same size as the original. (There is no error checking to enforce this.)
      Parameters:
      names - String[]
      Since:
      1.9.0