String和ByteBuffer互转

String 转换 ByteBuffer：

        //String 转换 ByteBuffer
    public static ByteBuffer getByteBuffer(String str) {
        return ByteBuffer.wrap(str.getBytes());
    }

ByteBuffer 转换 String：

        //ByteBuffer 转换 String
    public static String getString(ByteBuffer buffer) {
        Charset charset = null;
        CharsetDecoder decoder = null;
        CharBuffer charBuffer = null;
        try {
            charset = Charset.forName("UTF-8");
            decoder = charset.newDecoder();
                        //用这个的话，只能输出来一次结果，第二次显示为空
            // charBuffer = decoder.decode(buffer);
            charBuffer = decoder.decode(buffer.asReadOnlyBuffer());
            return charBuffer.toString();
        } catch (Exception ex) {
            ex.printStackTrace();
            return "error";
        }
    }