package eu.ehri.project.exporters.xml;
   
   import org.w3c.dom.Document;
   
   import javax.xml.transform.OutputKeys;
   import javax.xml.transform.Transformer;
   import javax.xml.transform.TransformerException;
   import javax.xml.transform.TransformerFactory;
   import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  import java.io.IOException;
  import java.io.OutputStream;
  
  /**
   * Helper for writing XML documents to a stream, with
   * configurable indent.
   */
  public class DocumentWriter {
      private final Document document;
      private final int indent;
  
      public DocumentWriter(Document document, int indent) {
          this.document = document;
          this.indent = indent;
      }
  
      public DocumentWriter(Document document) {
          this(document, 4);
      }
  
      public void write(OutputStream outputStream) throws IOException, TransformerException {
          TransformerFactory transformerFactory = TransformerFactory.newInstance();
          Transformer transformer = transformerFactory.newTransformer();
          transformer.setOutputProperty(OutputKeys.INDENT, "yes");
          transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount",
                  String.valueOf(indent));
  
          DOMSource source = new DOMSource(document);
          StreamResult result = new StreamResult(outputStream);
          transformer.transform(source, result);
      }
  }