com.devexperts.qd.util

Class ShortString

java.lang.Object

com.devexperts.qd.util.ShortString

public class ShortString
extends Object

Auxiliary class for converting short (up to 8 characters) strings into primitive long values and backwards. The conversion always skips zero characters in the input and never produces them in the output.

Method Summary

Modifier and Type	Method and Description
static String	decode(long code) Decodes long code into string.
static int	decodeInt(long code) Decodes short string into integer.
static long	encode(byte[] data, int offset, int length) Encodes a portion of a byte array up to 8 character to a long.
static long	encode(char[] data, int offset, int length) Encodes a portion of a char array up to 8 character to a long.
static long	encode(String str) Encodes string up to 8 characters as a long.
static long	encode(String str, int offset, int length) Encodes a portion of a string up to 8 character to a long.
static long	encodeInt(int value) Encodes integer number as a short string - up to 8 characters represented as a long.

Methods inherited from class java.lang.Object

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

Method Detail

encode

public static long encode(String str)

Encodes string up to 8 characters as a long. Zero characters (code point 0) are skipped, characters larger than 0xFF are prohibited. All other characters are concatenated together to form the code. The first character of string becomes the most significant byte of the resulting code. For example, "A" encodes as 0x41L, "AB" encodes as 0x4142L, etc. null and "" both encode as 0.

Parameters:

str - the string.

Returns:

the code.

Throws:

IllegalArgumentException - if length is greater than 8 or string contains character larger than 0xFF

encode

public static long encode(String str,
                          int offset,
                          int length)

Encodes a portion of a string up to 8 character to a long. This method is equivalent to expression encode(str.substring(offset, offset + length)).

Parameters:

str - the string.

offset - the initial offset of the substring.

length - the length of the substring to encode.

Returns:

the code.

Throws:

NullPointerException - if str is null.

IllegalArgumentException - if length is greater than 8 or string contains character larger than 0xFF

See Also:

encode(String)

encode

public static long encode(char[] data,
                          int offset,
                          int length)

Encodes a portion of a char array up to 8 character to a long. This method is equivalent to expression encode(new String(data, offset, length)).

Parameters:

data - the char array.

offset - the initial offset of the substring.

length - the length of the substring to encode.

Returns:

the code.

Throws:

NullPointerException - if str is null.

IllegalArgumentException - if length is greater than 8 or string contains character larger than 0xFF

See Also:

encode(String)

encode

public static long encode(byte[] data,
                          int offset,
                          int length)

Encodes a portion of a byte array up to 8 character to a long. This method is equivalent to expression encode(new String(data, 0, offset, length)).

Parameters:

data - the byte array.

offset - the initial offset of the substring.

length - the length of the substring to encode.

Returns:

the code.

Throws:

NullPointerException - if str is null.

IllegalArgumentException - if length is greater than 8

See Also:

encode(String)

decode

public static String decode(long code)

Decodes long code into string. This method skips zeros bytes in the given code and converts remaining bytes into characters from the most-significant byte to the least-significant one. Thus, all of 0x0000000000000041L, 0x0000004100000000L, and 0x4100000000000000L decode as "A". 0x4142L decodes as "AB", etc. 0 decodes as null.

Parameters:

code - the code.

Returns:

the string.

encodeInt

public static long encodeInt(int value)

Encodes integer number as a short string - up to 8 characters represented as a long. This method is equivalent to expression encode(Integer.toString(value)).

Parameters:

value - the number.

Returns:

the code.

Throws:

IllegalArgumentException - if number is lesser than -9999999 or larger than 99999999

decodeInt

public static int decodeInt(long code)

Decodes short string into integer. This method is equivalent to expression Integer.parseInt(decode(code)).

Parameters:

code - the code.

Returns:

the number.

Throws:

NumberFormatException - if the code does not contain a parsable integer