HTTP 500 error when sending XML to server

I am trying to send an XML file to my RESTful web server, and receive a XML file in return, however, I am getting a 500 error.

java.io.IOException: Server returned HTTP response code: 500 for URL: http://sps-psa-240:8080/NMCJWS/rest/jmsmon2/pub at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1436) at SendXML.send(SendXML.java:151)

at SendXML.main(SendXML.java:39)

Line 151 is InputStream response = uc.getInputStream();

If I uncomment System.out.println(((HttpURLConnection) uc).getResponseCode());, then I get the same error on OutputStreamWriter out = new OutputStreamWriter(uc.getOutputStream());

I know the server works because a coworker has this working in Obj-C.

Here is my code:

public class SendXML 
{
    public static void main(String[] args) throws SAXException, XPathExpressionException, ParserConfigurationException, 
                                                IOException, TransformerException 
    {   
        String xml = generateXML("AC24", "/fa/gdscc/dss24-apc");
        send("localhost", xml); 
    }

    public static String generateXML(String conn, String funcAddr) throws ParserConfigurationException, SAXException, 
                                                IOException, XPathExpressionException, TransformerException 
    {
        /*
         * <?xml version="1.0" encoding="UTF-8"?>
            <JMSMON2Req>
                <SubItem UID="iPAD-2031e616-de74-44a7-9292-3745d2b1ba21">
                    <FuncAddr>/fa/gdscc/con1-ac25</FuncAddr>
                    <ItemName>AZANG</ItemName>
                    <ItemName>ELANG</ItemName>
                    <Metadata key="UID">iPAD-2031e616-de74-44a7-9292-3745d2b1ba21</Metadata>
                    <Metadata key="CONN">1</Metadata>
                </SubItem>
            </JMSMON2Req>
         */

        DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
        domFactory.setNamespaceAware(true); // never forget this!
        DocumentBuilder builder = domFactory.newDocumentBuilder();
        Document doc = builder.parse("http://sps-psa-240:8080/NMCWS/rest/conn/subsys/prof?ss=" + conn + "&pt=IPAD_DASHBOARD");

        XPath xpath = XPathFactory.newInstance().newXPath();
        XPathExpression expr = xpath.compile("/SubscrProf/DataItem/DataItemName");

        Object result = expr.evaluate(doc, XPathConstants.NODESET);
        NodeList nodes = (NodeList) result;

        //build xml
        Document output = builder.newDocument();

        //create root
        org.w3c.dom.Element root = output.createElement("JMSMON2Req");
        output.appendChild(root);

            //create subitem
            org.w3c.dom.Element subItemNode = output.createElement("SubItem");
            subItemNode.setAttribute("UID", "IPAD-CN1-DSS26-SC151-PN230-AC26");
            root.appendChild(subItemNode);

                //create funcAddr
                org.w3c.dom.Element funcAddrNode = output.createElement("FuncAddr");
                Text text = output.createTextNode(funcAddr);
                funcAddrNode.appendChild(text);
                subItemNode.appendChild(funcAddrNode);

                //create itemname
                for (int i = 0; i < nodes.getLength(); i++) 
                {
                    org.w3c.dom.Element itemNameNode = output.createElement("SubItem");
                    text = output.createTextNode(nodes.item(i).getTextContent());
                    itemNameNode.appendChild(text);
                    subItemNode.appendChild(itemNameNode);
                }

                //create metadata uid
                org.w3c.dom.Element metaDataNode = output.createElement("Metadata");
                metaDataNode.setAttribute("key", "UID");
                text = output.createTextNode("IPAD-CN1-DSS26-SC151-PN230-AC26");
                metaDataNode.appendChild(text);
                subItemNode.appendChild(metaDataNode);

                //create metadata conn
                org.w3c.dom.Element metaDataNode2 = output.createElement("Metadata");
                metaDataNode2.setAttribute("key", "CONN");
                text = output.createTextNode("4");
                metaDataNode2.appendChild(text);
                subItemNode.appendChild(metaDataNode2);

        /////////////////
        //Output the XML

        //set up a transformer
        TransformerFactory transfac = TransformerFactory.newInstance();
        Transformer trans = transfac.newTransformer();
        trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        trans.setOutputProperty(OutputKeys.INDENT, "yes");

        //create string from xml tree
        StringWriter sw = new StringWriter();
        StreamResult out = new Stre开发者_StackOverflow中文版amResult(sw);
        DOMSource source = new DOMSource(output);

        trans.transform(source, out);
        String xmlString = sw.toString();

        //print xml
        System.out.println("Here's the xml:\n" + xmlString);

        return xmlString;
    }

    public static void send(String urladdress, String file) throws MalformedURLException, IOException
    {
        String charset = "UTF-8";
        String s = URLEncoder.encode(file, charset);

        // Open the connection and prepare to POST
        URLConnection uc = new URL(urladdress).openConnection();
        uc.setDoOutput(true);
        uc.setRequestProperty("Accept-Charset", charset);
        uc.setRequestProperty("Content-Type","text/xml");

        try
        {
            //System.out.println(((HttpURLConnection) uc).getResponseCode());
            OutputStreamWriter out = new OutputStreamWriter(uc.getOutputStream());
            out.write(s);
            out.flush();

            InputStream response = uc.getInputStream();
            BufferedReader r = new BufferedReader(new InputStreamReader(response));
            String line;

            while ((line = r.readLine()) != null)
                System.out.println(line);


            out.close();
            response.close();
        }
        catch (IOException e)
        { 
            e.printStackTrace();    // should do real exception handling
        }

    }
}

I figured out my problem. I had to encode xmlString in UTF-8

Look at the logs on the server. What is causing the 500 error?

Is this a RESTful web service, or a SOAP web service you're submitting to?

Consider using some sort of XML<->Object framework like JAXB or XStream.

Consider using some sort of RESTful web service framework like Jersey or RestEasy.

Consider using some sort of SOAP framework like JAX-WS or Apache Axis

Make sure you are using the right encoding. URLEncoder.encode is making the content safe for transfer as 'application/x-www-form-urlencoded', but you probably want to use UTF-8.

Also, new OutputStreamWriter(...) should specify the desired encoding. You are currently using the standard platform encoding which is probably iso-8859-1.

Third, don't try to mess around with URLConnection yourself, if there are plenty of libs around there, that can make you life easier.

Here is the send method done in Resty (Disclaimer: I'm the author of it). HTTPClient is another choice to consider as are other client-side libraries.

import us.monoid.web.Resty;
import static us.monoid.web.Resty.*;

Resty r = new Resty();
String result = r.text(urladdress, new Content("text/xml", file.getBytes("UTF-8"))).toString();