Package org.apache.commons.text
Class AlphabetConverter
java.lang.Object
org.apache.commons.text.AlphabetConverter
public final class AlphabetConverter extends Object
Convert from one alphabet to another, with the possibility of leaving certain characters unencoded.
The target and do not encode languages must be in the Unicode BMP, but the source language does not.
The encoding will all be of a fixed length, except for the 'do not encode' chars, which will be of length 1
Sample usage
Character[] originals; // a, b, c, d Character[] encoding; // 0, 1, d Character[] doNotEncode; // d AlphabetConverter ac = AlphabetConverter.createConverterFromChars(originals, encoding, doNotEncode); ac.encode("a"); // 00 ac.encode("b"); // 01 ac.encode("c"); // 0d ac.encode("d"); // d ac.encode("abcd"); // 00010dd
#ThreadSafe# AlphabetConverter class methods are thread-safe as they do not change internal state.
- Since:
- 1.0
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Method Summary
Modifier and Type Method Description static AlphabetConverter
createConverter(Integer[] original, Integer[] encoding, Integer[] doNotEncode)
Create an alphabet converter, for converting from the original alphabet, to the encoded alphabet, while leaving the characters in doNotEncode as they are (if possible).static AlphabetConverter
createConverterFromChars(Character[] original, Character[] encoding, Character[] doNotEncode)
Create an alphabet converter, for converting from the original alphabet, to the encoded alphabet, while leaving the characters in doNotEncode as they are (if possible).static AlphabetConverter
createConverterFromMap(Map<Integer,String> originalToEncoded)
Create a new converter from a map.String
decode(String encoded)
Decode a given string.String
encode(String original)
Encode a given string.boolean
equals(Object obj)
int
getEncodedCharLength()
Get the length of characters in the encoded alphabet that are necessary for each character in the original alphabet.Map<Integer,String>
getOriginalToEncoded()
Get the mapping from integer code point of source language to encoded string.int
hashCode()
String
toString()
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Method Details
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encode
Encode a given string.- Parameters:
original
- the string to be encoded- Returns:
- The encoded string,
null
if the given string is null - Throws:
UnsupportedEncodingException
- if chars that are not supported are encountered
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decode
Decode a given string.- Parameters:
encoded
- a string that has been encoded using this AlphabetConverter- Returns:
- The decoded string,
null
if the given string is null - Throws:
UnsupportedEncodingException
- if unexpected characters that cannot be handled are encountered
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getEncodedCharLength
public int getEncodedCharLength()Get the length of characters in the encoded alphabet that are necessary for each character in the original alphabet.- Returns:
- The length of the encoded char
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getOriginalToEncoded
Get the mapping from integer code point of source language to encoded string. Use to reconstruct converter from serialized map.- Returns:
- The original map
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toString
-
equals
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hashCode
public int hashCode() -
createConverterFromMap
Create a new converter from a map.- Parameters:
originalToEncoded
- a map returned from getOriginalToEncoded()- Returns:
- The reconstructed AlphabetConverter
- See Also:
getOriginalToEncoded()
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createConverterFromChars
public static AlphabetConverter createConverterFromChars(Character[] original, Character[] encoding, Character[] doNotEncode)Create an alphabet converter, for converting from the original alphabet, to the encoded alphabet, while leaving the characters in doNotEncode as they are (if possible).Duplicate letters in either original or encoding will be ignored.
- Parameters:
original
- an array of chars representing the original alphabetencoding
- an array of chars representing the alphabet to be used for encodingdoNotEncode
- an array of chars to be encoded using the original alphabet - every char here must appear in both the previous params- Returns:
- The AlphabetConverter
- Throws:
IllegalArgumentException
- if an AlphabetConverter cannot be constructed
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createConverter
public static AlphabetConverter createConverter(Integer[] original, Integer[] encoding, Integer[] doNotEncode)Create an alphabet converter, for converting from the original alphabet, to the encoded alphabet, while leaving the characters in doNotEncode as they are (if possible).Duplicate letters in either original or encoding will be ignored.
- Parameters:
original
- an array of ints representing the original alphabet in codepointsencoding
- an array of ints representing the alphabet to be used for encoding, in codepointsdoNotEncode
- an array of ints representing the chars to be encoded using the original alphabet - every char here must appear in both the previous params- Returns:
- The AlphabetConverter
- Throws:
IllegalArgumentException
- if an AlphabetConverter cannot be constructed
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