Java I18n and Unicode

1
Java I18n and Unicode

• JaxJug lightning talk
• 4/15/09

2
Java I18n   

• Native support for Unicode
• Localization
• Create properties files
• Locale object
• ResourceBundles
• Other locale-dependent data

3
Issues

• But what about when you are talking to someone
  else?
• Different encodings
• BE and LE
• String s new String(buffer, "UTF8")
• s.getBytes("UTF8")
• public String parseMessage(byte buffer)
•       StringBuffer buffer new StringBuffer()
•       try
•           InputStreamReader is  new InputStreamRe
  ader(new ByteArrayInputStream(buffer), "UTF-16LE")
  )
•           BufferedReader br new
  BufferedReader(is)
•           int ch
•           while ((ch br.read() ! -1)
•               buffer.append((char)ch)
•           
•           br.close()
•           return buffer.toString()
•         catch (IOException e)
•           e.printStackTrace()

4
Converting Unicode

• import java.io.
• public class UnicodeFormatter
• static public String byteToHex(byte b)
• // Returns hex String representation of byte b
• char hexDigit
• '0', '1', '2', '3', '4', '5', '6', '7',
• '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
• char array hexDigit(b gtgt 4) 0x0f,
• hexDigitb 0x0f
• return new String(array)
• static public String charToHex(char c)
• // Returns hex String representation of char c
• byte hi (byte) (c gtgtgt 8)
• byte lo (byte) (c 0xff)
• return byteToHex(hi) byteToHex(lo)

5
Regular Expressions and Unicode

• What is a character?
• Ñ  
• \u00F1 
• OR 
• \u006E \u0303
• Matching graphemes - .
• Canonical equivalence
• Pattern.compile (pattern, CANON_EQ)
• http//www.regular-expressions.info/unicode.html