How to write a file to xml with STAX?

Question

I have a problem writing a file to a xml. Here is how this element looks in xsd.

<xs:element name="File">
        <xs:complexType>
            <xs:simpleContent>
                <xs:extension base="xs:base64Binary">   
                </xs:extension>
            </xs:simpleContent>
        </xs:complexType>
    </xs:element>

Here is my method to write:

       private void writeFile (XMLStreamWriter2 sw, final InputStream is){
//is - inputstream from file
            try {
                OutputStream output = null;
                InputStream input = new Base64InputStream(is, true);
                int count;

                    int BUFFER_SIZE = 4000;
                    byte[] buffer = new byte[BUFFER_SIZE];
                    output = new FileOutputStream(new File("D:\\test.txt"));
                    while ((count = input.read(buffer)) != -1) {

                            output.write(buffer, 0, count);
                            sw.writeBinary(buffer, 0, count);

                    }
                    is.close();
                    input.close();
                    output.close();
            } catch (XMLStreamException ex) {
                Logger.getLogger(StaxFinal.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(StaxFinal.class.getName()).log(Level.SEVERE, null, ex);
            } 
        }

The content of test.txt is valid base-64 string, while content of File xml elements file is not (i'm checking with http://www.opinionatedgeek.com/dotnet/tools/base64decode/ ). why

EDIT Trying to use this, but i get a lot of carriage-return symbols #xd;

private void writeFile (XMLStreamWriter sw, InputStream is){
   //is - FileInputStream
    Reader reader = new InputStreamReader(new Base64InputStream(is, true));
    char[] buf = new char[4096];
    int n;

        while( (n = reader.read(buf)) >= 0 ) {
                sw.writeCharacters(buf, 0, n-3 );
        }
}

EDIT Method:

writeRaw(char[] chars, int i, int i1)

works fine. Strange, but woodstox's readElementAsBinary reads and decodes base64 for me. Why writeBinary doesn't write valid base64? Anyways, thank you skaffman! You are awesome!

Answer 1

I assume you use the Base64InputStream from Apache Commons Codec. It also offers a constructor with four arguments, that can be used to turn off line breaks completely. Adjusting your method from the question you can write valid Base64 output like this:

private void writeFile (XMLStreamWriter sw, InputStream is){
    //is - FileInputStream
    Reader reader = new InputStreamReader(new Base64InputStream(is, true, -1, null));
    char[] buf = new char[4096];
    int n;
    while( (n = reader.read(buf)) >= 0 ) {
        sw.writeCharacters(buf, 0, n);
    }
}

Answer 2

Based on the javadoc of Base64InputStream: if you provide two parameters to the constructor (InputStream in, boolean doEncode) then it creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original provided InputStream. and doEncode - true if we should encode all data read from us, false if we should decode.

Because I am not sure of what your function should do, I can only recon this:

• either you could turn doEncode to false (to store a decoded text in your xml file)
• or simply use the inputstream is directly (to copy/paste the text file towards the xml)