Java and Unicode

External

• http://www.oracle.com/us/technologies/java/supplementary-142654.html

Internal

• Character Encoding
• Java char

Overview

Character information is maintained in Java by the primitive type char, which was designed based on the original Unicode 1.0 specification that allowed only 2¹⁶ code points, so it was defined as a fixed-with 16-bit/2-byte entity. Since then, the Unicode standard has evolved to allow for characters whose representation requires more than 16 bits.

Java platform uses the UTF-16 representation in char arrays and in the String, StringBuffer and StringBuilder classes.

The Basic Multilingual Plane characters are represented as char instances, while the supplementary characters are represented as a pair of char values. Java 5 introduced enhancements to correctly handle Unicode supplementary characters. For more details about supplementary character representation in Java see https://docs.oracle.com/javase/10/docs/api/java/lang/Character.html.