Question

I have a xml file content as string in my servlet, I need to call another URL with multipart post request to upload it as xml file.

Is there a way it can be done?

So far this is what i am doing

private def createConfiguration(def sessiontoken)
{
    /*reqParams is request.getParameterMap(), fileParams is again a map*/
    def charset = "UTF-8";
    def query = String.format("emailaddress=%s&projectid=%s&cfgname=%s&cfgdesc=%s&cfgfile=%s",
        URLEncoder.encode(sessiontoken, charset),
        URLEncoder.encode(reqParams.c_Cfgname[0], charset),
        URLEncoder.encode(reqParams.c_Cfgdesc[0], charset),
        URLEncoder.encode(reqParams.c_Cfgtype[0], charset),
        URLEncoder.encode(reqParams.CFGFILE[0], charset),)

    URLConnection connection = new URL(fileParams.login).openConnection()
    connection.setDoOutput(true)
    connection.setRequestProperty("Accept-Charset", charset)
    connection.setRequestProperty("Content-Type", "multipart/form-data;charset=" + charset)
    try {
        connection.getOutputStream().write(query.getBytes(charset))
    }
    finally {
        connection.getOutputStream().close()
    }
    InputStream response = connection.getInputStream()
    def xmlString=response.getText()
    xmlString
}

Below is the exception fetched

SEVERE: Servlet.service() for servlet RedirectRequest threw exception
java.io.IOException: Server returned HTTP response code: 800 for URL: http://abhishek157:10070/project/create.action
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$getInputStream.call(Unknown Source)
.
.

Update

Got this very usefull link by BalusC So I used it.

private def getStreamFromString(str)
{
    // convert String into InputStream
    InputStream is = new ByteArrayInputStream(str.getBytes())
    is
}

private def createConfiguration(def sessiontoken)
{


    println "ok good $sessiontoken"
    def charset = "UTF-8"
    def boundary = Long.toHexString(System.currentTimeMillis())
    def CRLF = "\r\n"
    String param = "value"

    URLConnection connection = new URL(fileParams.create).openConnection()
    println fileParams.create
    connection.setDoOutput(true)
    connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    PrintWriter writer = null
    try {

        OutputStream output = connection.getOutputStream()
        writer = new PrintWriter(new OutputStreamWriter(output, charset), true)

        // Sending normal param.
        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"sessiontoken\"$CRLF$CRLF$sessiontoken").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgname\"$CRLF$CRLF${reqParams.c_Cfgname[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgdesc\"$CRLF$CRLF${reqParams.c_Cfgdesc[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgenv\"$CRLF$CRLF${reqParams.c_Cfgtype[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        // Sending xml file.
        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgfile\"; filename=\"" + reqParams.FILENAME[0] + "\"").append(CRLF)
        writer.append("Content-Type: text/xml; charset=" + charset).append(CRLF)
        writer.append(CRLF).flush()
        BufferedReader reader = null
        try {
            reader = new BufferedReader(new InputStreamReader(getStreamFromString(reqParams.CFGFILE[0]), charset))
            for (String line; (line = reader.readLine()) != null;) {
                writer.append(line).append(CRLF)
            }
        }
        catch(Exception e)  {
            e.printStackTrace()
        }
        finally {
            if (reader != null) try { reader.close(); } catch (IOException logOrIgnore) {}
        }
        writer.flush();
        writer.append("--" + boundary + "--").append(CRLF)
    } 
    finally {
        if (writer != null) writer.close();
    }
    InputStream response = connection.getInputStream()
    def xmlString=response.getText()
    xmlString
}

and on the console I get

http://abhishek157:10070/project/create.action
done

but it is not at all hitting http://abhishek157:10070/project/create.action
Any help?

More Updates

The real request (working from html form, where I select file from web browser)

-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="sessiontoken"

4611685684744086913
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgname"

sadf
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgdesc"

sadf
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgenv"

Production
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgfile"; filename="C:\Simon\xmls\agentind.xml"
Content-Type: text/xml

<?xml version="1.0" encoding="UTF-8"?> and so on...

Updated params part after matching from the actual request in fiddler. See createConfiguration function

Exception fetched (while calling create.action from servlet)

Note: I checked in the servlet before sending the params in create.action, all are valid

java.lang.NumberFormatException: null 

None of the params are read in the server, all are coming as null. Where is the problem. Please help.

Answer 1

In your updated code, you forgot to call connection.getInputStream(); to actually send the HTTP request (and to retrieve the HTTP response).