e186. converting between strings (unicode) and other character set encodings.txt

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Many network protocols and files store their characters with a byte-oriented character set such as ISO-8859-1 (ISO-Latin-1). However, Java's native character encoding is Unicode. 
This example demonstrates how to convert ISO-8859-1 encoded bytes in a ByteBuffer to a string in a CharBuffer and visa versa. 

    // Create the encoder and decoder for ISO-8859-1
    Charset charset = Charset.forName("ISO-8859-1");
    CharsetDecoder decoder = charset.newDecoder();
    CharsetEncoder encoder = charset.newEncoder();
    
    try {
        // Convert a string to ISO-LATIN-1 bytes in a ByteBuffer
        // The new ByteBuffer is ready to be read.
        ByteBuffer bbuf = encoder.encode(CharBuffer.wrap("a string"));
    
        // Convert ISO-LATIN-1 bytes in a ByteBuffer to a character ByteBuffer and then to a string.
        // The new ByteBuffer is ready to be read.
        CharBuffer cbuf = decoder.decode(bbuf);
        String s = cbuf.toString();
    } catch (CharacterCodingException e) {
    }

In the example above, the encoding and decoding methods created new ByteBuffers into which to encode or decoding the data. Moreover, the newly allocated ByteBuffers are non-direct (e168 Determining If a ByteBuffer Is Direct). The encoder and decoder provide methods that use a supplied ByteBuffer rather than create one. Here's an example that uses these methods: 
    // Create a direct ByteBuffer.
    // This buffer will be used to send and recieve data from channels.
    ByteBuffer bbuf = ByteBuffer.allocateDirect(1024);
    
    // Create a non-direct character ByteBuffer
    CharBuffer cbuf = CharBuffer.allocate(1024);
    
    // Convert characters in cbuf to bbuf
    encoder.encode(cbuf, bbuf, false);
    
    // flip bbuf before reading from it
    bbuf.flip();
    
    // Convert bytes in bbuf to cbuf
    decoder.decode(bbuf, cbuf, false);
    
    // flip cbuf before reading from it
    cbuf.flip();

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