Posting a document using HttpURLConnection?

have you tried:
httpcon.setRequestMethod("POST")

You need that. The default request method is GET, which  has an upper bound on the amount of data it can transmit.

Your request needs to be formatted specifically for a multipart/form-data, you can't just send the file.

check out http://jakarta.apache.org/commons/ for the HttpClient.  I don't know if it handles multipart requests yet, but it probably wouldn't hurt to look.

-- objects,

I tried wrapping the content of my text file as described in RFC1867, but could not succeed. I am sure I am doing something wrong. Could you please provide some pointer/link for a valid example/article.

Here is the code snippet I tried...
....
       String req = //"Content-type: multipart/form-data, boundary=AaB03x\r\n\r\n"
                     "\r\n--AaB03x\r\n"
                     +"content-disposition: form-data; name=\"file\"; filename=\"testdoc.xml\"\r\n"
                     +"Content-Type: text/plain\r\n\r\n"
                     +"<Hello>Hello There</Hello>\r\n"
                     +"--AaB03x--\r\n";

        DataOutputStream os = new DataOutputStream(httpcon.getOutputStream());
        os.writeBytes(req);
        os.flush();
....

-- heinousjay,

HttpClient doesn't seems to have the support yet for the multipart.

     String req = "Content-type: multipart/form-data, boundary=AaB03x\r\n\r\n"
                    +"--AaB03x\r\n"
                    +"content-disposition: form-data; name=\"file\"; filename=\"testdoc.xml\"\r\n"
                    +"Content-Type: text/plain\r\n\r\n"
                    +"<Hello>Hello There</Hello>\r\n"
                    +"--AaB03x--\r\n";
-----------------------------------------------------------
      String req = //"Content-type: multipart/form-data, boundary=AaB03x\r\n\r\n"
                    "\r\n--AaB03x\r\n"
                    +"content-disposition: form-data; name=\"file\"; filename=\"testdoc.xml\"\r\n"
                    +"Content-Type: text/plain\r\n\r\n"
                    +"<Hello>Hello There</Hello>\r\n"
                    +"--AaB03x--\r\n";

should be something like this:
...
httpcon.setRequestProperty("Content-Type", "multipart/form-data, boundary=AaB03x"); // this is new line
httpcon.connect();

System.out.println("Posting " +docPath +"...");
File file = new File(docPath);
FileInputStream is = new FileInputStream(file);
OutputStream os = httpcon.getOutputStream();
// this is new line
os.write("content-disposition: form-data; name=\"file\"; filename=\"testdoc.xml\"\r\nContent-Type: text/plain\r\n\r\n".getBytes());
();
// POST
// Read bytes until EOF to write
byte[] buffer = new byte[4096];
int bytes_read;    // How many bytes in buffer
while((bytes_read = is.read(buffer)) != -1) {
  os.write(buffer, 0, bytes_read);
}
os.write("--AaB03x".getBytes()); // another 2 new lines
os.flush(); //
os.close();
is.close();

System.out.println("Done...");
                         

Hi,

just a little addition Venc75's solution. Be sure to prepend a "\r\n" before writing the boundary after the file, this is part of the spec. The 2nd boundary must look like this.

os.write("\r\n--AaB03x".getBytes());

bye, x4u.

I've found server can be extremely fussy about multipart form posts, on character wrong and the whole thing fails.

Try http://www.innovation.ch/java/HTTPClient/, I believe it supports multipart posts.

x4u,
====

os.write("\r\n--AaB03x".getBytes());
 should be
os.write("\r\n--AaB03x--".getBytes());

objects,
========

Did not find any multipart specific API there!

All,
====

I could run my *JAVA HTTP Client program* successfully using Tomcat4.0.3 and a URL Upload.jsp (that uses com.orelly.servlet.MultiPart). But I am also trying another server called "Zope" the same program gives me a 500 error. I am posting the error message below if you can give some clue...


null: HTTP/1.1 500 Internal Server Error
Server: Zope/(Zope 2.5.1 (binary release, python 2.1, win32-x86), python 2.1.3, win32) ZServer/1.1b1
Date: Thu, 10 Oct 2002 12:57:34 GMT
Bobo-Exception-File: C:\Zope\bin\lib\cgi.py
Content-Type: text/html
Bobo-Exception-Type: ValueError
Bobo-Exception-Value: bobo exception
Etag:
Content-Length: 1704
Bobo-Exception-Line: 603

getRequestMethod   : POST
getResponseCode    : 500
getResponseMessage : Internal Server Error


---------------------------------------------------------
Here is my entire working program
---------------------------------------------------------
import java.io.*;
import java.net.*;

/**
 *    RFC 1867
 *    ========
 *        Content-type: multipart/form-data, boundary=AaB03x
 *
 *        --AaB03x
 *        content-disposition: form-data; name="field1"
 *
 *        Joe Blow
 *        --AaB03x
 *        content-disposition: form-data; name="pics"; filename="file1.txt"
 *        Content-Type: text/plain
 *
 *         ... contents of file1.txt ...
 *        --AaB03x--
 */
public class PostDocument {
    public static void main(String[] args) throws Exception {
        //
        // CONSTANTS
        //
        String url = "http://localhost:8080/Examples/FileLibrary/addFile";   // <--- Zope/Python
        // String url = "http://localhost:8080/rcn/jsp/UploadFile.jsp?action=upload"; // <--- Tomcat/JSP
        String docPath = "D:\\rcn\\java\\HttpURLConnection\\testdoc.txt";
        String bndry = "AaB03x";
        String paramName = "file";
        String fileName = "testdoc.txt";

        //
        // CREATE AN HTTP CONNECTION
        //
        HttpURLConnection httpcon = (HttpURLConnection) ((new URL(url).openConnection()));
        httpcon.setDoOutput(true);
        httpcon.setUseCaches(false); // ??? Not Required?
        httpcon.setRequestMethod("POST");
        httpcon.setRequestProperty("Content-type", "multipart/form-data, boundary=" +bndry); // this is new line
        httpcon.connect();

        //
        // OPEN THE READ AND WRITE STREAMS
        //
        System.out.println("Posting " +docPath +"...");
        File file = new File(docPath);
        FileInputStream is = new FileInputStream(file);
        OutputStream os = httpcon.getOutputStream();

        //
        // WRITE THE FIRST/START BOUNDARY
        //
        String disptn = "--" +bndry +"\r\ncontent-disposition: form-data; name=\"" +paramName +"\"; filename=\"" +fileName +"\"\r\nContent-Type: text/plain\r\n\r\n";
        System.out.print(disptn);
        os.write(disptn.getBytes());

        //
        // WRITE THE FILE CONTENT
        //
        byte[] buffer = new byte[4096];
        int bytes_read;
        while((bytes_read = is.read(buffer)) != -1) {
            os.write(buffer, 0, bytes_read);
            System.out.print(new String(buffer, 0, bytes_read));
        }

        //
        // WRITE THE CLOSING BOUNDARY
        //
        String boundar = "\r\n--" +bndry +"--";
        System.out.print(boundar);
        os.write(boundar.getBytes()); // another 2 new lines

        //
        // FLUSH / CLOSE THE STREAMS
        //
        os.flush();
        os.close();
        is.close();

        // DEBUG
        System.out.println("\n....Done!!!...\n\n");
        dump(httpcon);
    }

    public static void dump(HttpURLConnection httpcon) throws IOException {
        int n=0; // n=0 has no key, and the HTTP return status in the value field
        String headerKey;
        String headerVal;

        while (true){
            headerKey = httpcon.getHeaderFieldKey(n);
            headerVal = httpcon.getHeaderField(n);

            if (headerKey != null || headerVal != null) {
                System.out.println(headerKey +": " +headerVal);        
            }
            else {
                break;
            }

            n++;
        }

        System.out.println();
        System.out.println("getRequestMethod   : " +httpcon.getRequestMethod());
        System.out.println("getResponseCode    : " +httpcon.getResponseCode());
        System.out.println("getResponseMessage : " +httpcon.getResponseMessage());
    }
}