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APPENDIX A
Java Encoding Schemes
This appendix describes the character-encoding schemes that are supported by the Java
platform.
US-ASCII
US-ASCII is a 7-bit character set and encoding that covers the English-language alphabet. It is
not large enough to cover the characters used in other languages, however, so it is not very
useful for internationalization.
ISO-8859-1
ISO-8859-1 is the character set for Western European languages. It’s an 8-bit encoding scheme
in which every encoded character takes exactly 8 bits. (With the remaining character sets, on the
other hand, some codes are reserved to signal the start of a multibyte character.)
UTF-8
UTF-8 is an 8-bit encoding scheme. Characters from the English-language alphabet are all
encoded using an 8-bit byte. Characters for other languages are encoded using 2, 3, or even 4
bytes. UTF-8 therefore produces compact documents for the English language, but for other
languages, documents tend to be half again as large as they would be if they used UTF-16. If the
majority of a document’s text is in a Western European language, then UTF-8 is generally a
good choice because it allows for internationalization while still minimizing the space required
for encoding.
UTF-16
UTF-16 is a 16-bit encoding scheme. It is large enough to encode all the characters from all the
alphabets in the world. It uses 16 bits for most characters but includes 32-bit characters for
ideogram-based languages such as Chinese. A Western European-language document that uses
UTF-16 will be twice as large as the same document encoded using UTF-8. But documents
written in far Eastern languages will be far smaller using UTF-16.
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