Java in a Nutshell, 5th Edition

Name

CharsetDecoder

Synopsis

A CharsetDecoder is a “decoding engine” that converts a sequence of bytes into a sequence of characters based on the encoding of some charset. Obtain a CharsetDecoder from the Charset that represents the charset to be decoded. If you have a complete sequence of bytes to be decoded in a ByteBuffer you can pass that buffer to the one-argument version of decode( ) . This convenience method decodes the bytes and stores the resulting characters into a newly allocated CharBuffer, resetting and flushing the decoder as necessary. It throws an exception if there are problems with the bytes to be decoded.

Typically, however, the three-argument version of decode( ) is used in a multistep decoding process:

1. Call the reset( ) method, unless this is the first time the CharsetDecoder has been used.

2. Call the three-argument version of decode( ) one or more times. The third argument should be true on, and only on, the last invocation of the method. The first argument to decode( ) is a ByteBuffer that contains bytes to be decoded. The second argument is a CharBuffer into which the resulting characters are stored. The return value of the method is a CoderResult object that specifies the state of the ongoing the decoding operation. The possible CoderResult return values are detailed below. In a typical case, however, decode( ) returns after it has decoded all of the bytes in the input buffer. In this case, you would then typically fill the input buffer with more bytes to be decoded, ...