Java Examples in a Nutshell, 3rd Edition

Character Encodings

Text representation has traditionally been one of the most difficult problems of internationalization. Java, however, solves this problem quite elegantly and hides the difficult issues. Java uses Unicode internally, so it can represent essentially any character in any commonly used written language. As I noted earlier, the remaining task is to convert Unicode to and from locale-specific encodings. Java includes quite a few internal byte-to-char and char-to-byte converters that handle converting locale-specific character encodings to Unicode and vice versa. Although the converters themselves are not public, they are accessible through the InputStreamReader and OutputStreamWriter classes, which are character streams included in the java.io package.

Any program can automatically handle locale-specific encodings simply by using these character stream classes to do their textual input and output. Note that the FileReader and FileWriter classes use these streams to automatically read and write text files that use the platform’s default encoding.

Example 8-2 shows a simple program that works with character encodings. It converts a file from one specified encoding to another by converting from the first encoding to Unicode and then from Unicode to the second encoding. Note that most of the program is taken up with the mechanics of parsing argument lists, handling exceptions, and so on. Only a few lines are required to create the InputStreamReader and OutputStreamWriter ...