Convert DOM element encoding from CP1251 to UTF-8

Question

I have a simple server-side code that takes request xml and inserts it as string into Oracle database Clob column. The problem is that client-side sends request xml with CP1251 encoded text, but I need to insert it into Oracle with UTF-8 encoding. Now the code that I use for CP1251 is:

        Element soapinElement = (Element) streams.getSoapin().getValue().getAny();  //retrieve request xml      
        Node node = (Node) soapinElement;
        Document document = node.getOwnerDocument();
        DOMImplementationLS domImplLS = (DOMImplementationLS) document.getImplementation();         
        LSSerializer serializer = domImplLS.createLSSerializer();
        LSOutput output = domImplLS.createLSOutput();
        output.setEncoding("CP1251");
        Writer stringWriter = new StringWriter();
        output.setCharacterStream(stringWriter);
        serializer.write(document, output);
        String soapinString = stringWriter.toString();

This code recognizes text encoded in CP1251. The task is to make the same but with readable text encoded in UTF-8. Please suggest any ideas.

I tried this, but it produced unreadable characters instead of cyrillic:

        Element soapinElement = (Element)   streams.getSoapin().getValue().getAny();            
        Node node = (Node) soapinElement;
        Document document = node.getOwnerDocument();
        DOMImplementationLS domImplLS = (DOMImplementationLS) document.getImplementation();         
        LSSerializer serializer = domImplLS.createLSSerializer();
        LSOutput output = domImplLS.createLSOutput();
        output.setEncoding("CP1251");
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        output.setByteStream(byteArrayOutputStream);
        serializer.write(document, output);
        byte[] result = byteArrayOutputStream.toByteArray();
        InputStream is = new ByteArrayInputStream(result);
        Reader reader = new InputStreamReader(is, "CP1251");
        OutputStream out = new ByteArrayOutputStream();
        Writer writer = new OutputStreamWriter(out, "UTF-8");
        char[] buffer = new char[10];
        int read;
        while ((read = reader.read(buffer)) != -1) {
            writer.write(buffer, 0, read);
        }           
        reader.close();
        writer.close();
        String soapinString = out.toString();

Answer 1

You can decode the CP1251 characterset Data like below

Charset utf8charset = Charset.forName("UTF-8");
Charset cp1251charset = Charset.forName("CP1251");

// decode CP1251
        CharBuffer data = cp1251charset.decode(ByteBuffer.wrap(result));

and encode to UTF-8 character set

// encode UTF-8
        ByteBuffer outputBuffer = utf8charset.encode(data);

and convert the ByteBuffer to byte[]

// UTF-8 Value        
        byte[] outputData = outputBuffer.array();

This should probably solve your issue.