Java and Unicode

External

• https://docs.oracle.com/javase/10/docs/api/java/lang/Character.html
• 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. For details on how characters are represented internally by Java, see the "Character Representation" section.

U+n Notation Support

U+n notation is supported in Java as follows:

Character Representation

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, as the char data type provides sufficient storage capacity for the entire BMP range.

The supplementary characters are represented as a pair of char values. Java 5, which supports Unicode 4.0, introduced enhancements to correctly handle Unicode supplementary characters.