Unicode Tutorials - Herong's Tutorial Examples
Dr. Herong Yang, Version 5.10

Java Language and Unicode Characters

This chapter provides notes and tutorial examples on Unicode support in Java language. Topics including Unicode versions supported in different JDK versions; using 'int' and 'String' data type to store single and multiple Unicode characters; Unicode utility methods in the 'Character' class; 'char' element index pointers and character locations in 'String' objects.

Unicode Versions Supported in Java-History

'int' and 'String' - Basic Data Types for Unicode

"Character" Class with Unicode Utility Methods

Character.toChars() - "char" Sequence of Code Point

Character.getNumericValue() - Numeric Value of Code Point

"String" Class with Unicode Utility Methods

String.length() Is Not Number of Characters

String.toCharArray() Returns the UTF-16BE Sequence

Conclusions:

  • From JDK 1.0 to JDK 1.4, Java can only support BMP (Basic Multilingual Plane) characters.
  • From J2SE 5.0 (JDK 1.5) to any newer versions, Java can support the full range, U+0000 to U+10FFFF, of Unicode characters.
  • "Character" objects can not represent all Unicode characters any more. Store code points as "int" values represent Unicode characters.
  • The "Character" class offers static utility methods to help Unicode character processing.
  • The length() method on a "String" object returns the number of "char" elements used to store Unicode characters represented by the "String" object.
  • The codePointCount() method on a "String" object returns the number of Unicode characters represented by the "String" object.
  • The toCharArray() method on a "String" object returns the UTF-16BE encoded "char" sequence of Unicode characters represented by the "String" object.

Table of Contents

 About This Book

 Character Sets and Encodings

 ASCII Character Set and Encoding

 GB2312 Character Set and Encoding

 GB18030 Character Set and Encoding

 JIS X0208 Character Set and Encodings

 Unicode Character Set

 UTF-8 (Unicode Transformation Format - 8-Bit)

 UTF-16, UTF-16BE and UTF-16LE Encodings

 UTF-32, UTF-32BE and UTF-32LE Encodings

Java Language and Unicode Characters

 Character Encoding in Java

 Character Set Encoding Maps

 Encoding Conversion Programs for Encoded Text Files

 Using Notepad as a Unicode Text Editor

 Using Microsoft Word as a Unicode Text Editor

 Using Microsoft Excel as a Unicode Text Editor

 Unicode Code Point Blocks - Code Charts

 Outdated Tutorials

 References

 Printable Copy - PDF Version

Dr. Herong Yang, updated in 2012
Java Language and Unicode Characters