We are working on uploading image to our server from android device. Image is successfully uploading in server while using both mobile data and Wi-Fi, except one particular network which we are currently using. This new network setup don’t let pass any data from client end which has greater MTU size than 1460. So, all the packets from android device are rejected and cannot reach the server. Our iOS app can upload image to same server successfully with same network. We have found with tracing that iOS reduces the packet or chunk size if one packet is not successfully sent. But android devices are not behaving like that. We have also found that some social networking android apps can successfully upload image with our network. Some would probably say to change our network with correct settings, but we don’t want to do that as if we can have a defective network, some other people can also have that, where our android app will not work properly.
The works we have tried so far (all of which are working, except the new network) are given below:
Main code which we were using from first:
private boolean uploadImage(String fileLoc, String title){
try {
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
URL connectURL;
connectURL = new URL(baseUrlString); // our server url to upload image
FileInputStream fileInputStream = new FileInputStream(fileLoc);
// ------------------ CLIENT REQUEST
// Open a HTTP connection to the URL
HttpURLConnection conn = (HttpURLConnection) connectURL
.openConnection();
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Don't use a cached copy.
conn.setUseCaches(false);
//conn.setChunkedStreamingMode(512);
// Use a post method.
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + boundary);
//conn.setFixedLengthStreamingMode(137931);
DataOutputStream dos = new DataOutputStream(
conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\""
+ param1 + "\"" + lineEnd
+ lineEnd
+ title
+ lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"file\";filename=\""
+ fileLoc
+ "\""
+ lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
int bytesAvailable = fileInputStream.available();
int maxBufferSize = 1024;
int bufferSize = Math.min(bytesAvailable, maxBufferSize);
byte[] buffer = new byte[bufferSize];
// read file and write it into form...
int bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// close streams
fileInputStream.close();
dos.flush();
InputStream is = conn.getInputStream();
// retrieve the response from server
int ch;
StringBuffer b = new StringBuffer();
while ((ch = is.read()) != -1) {
b.append((char) ch);
}
String response;
response = b.toString().trim();
dos.close();
// here some work with response
return sucs;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
Here we have also tried with
conn.setChunkedStreamingMode(512);
conn.setRequestProperty("Transfer-Encoding", "chunked");
to limit the chunk size, but it is ignored as the documentation says it is only a hint.
We have also tried with
conn.setFixedLengthStreamingMode(calculatedValueOfbytesForSameImage);
but failed.
Then we tried to implement other methods found in the web using Multipart and Socket:
https://stackoverflow.com/a/16529053/1246639
https://stackoverflow.com/a/19188010/1246639
https://stackoverflow.com/a/22803149/1246639
https://groups.google.com/forum/#!msg/android-developers/SZ5MzO6wr6I/Ol4ZL1Au3U0J
All methods working except our network. Have also tried combining Multipart to ByteArrayOutputStream as https://stackoverflow.com/a/10225966/1246639. But still not working.
Is there any other method available to control the chunk size using other class like the InterfaceAddress or native support or if we are missing something in methods tried above? Thanks.....
Related
I am using HttpURLConnection class to upload text file to my Apache server. For server side code I used php to handle the POST request. I was wondering , how the same thing can be done other then PHP, or the PHP is the best way to handle file uploading on server side?..Also I cannot find any jsp or java code on server side to handle http post request..any code snippet that does same thing other then PHP would be really helpful..Cause I think java or jsp would be easier to code ..Thanks
Android code to upload file:
public void upLoad()
{
String exsistingFileName = path+"//"+"test.txt";
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
try {
// ------------------ CLIENT REQUEST
Log.e(Tag, "Inside second Method");
FileInputStream fileInputStream = new FileInputStream(new File(
exsistingFileName));
// open a URL connection to the Servlet
URL url = new URL(urlString);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Don't use a cached copy.
conn.setUseCaches(false);
// Use a post method.
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + boundary);
DataOutputStream dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: post-data; name=uploadedfile;filename="
+ exsistingFileName + "" + lineEnd);
dos.writeBytes(lineEnd);
Log.e(Tag, "Headers are written");
// create a buffer of maximum size
int bytesAvailable = fileInputStream.available();
int maxBufferSize = 1000;
// int bufferSize = Math.min(bytesAvailable, maxBufferSize);
byte[] buffer = new byte[bytesAvailable];
// read file and write it into form...
int bytesRead = fileInputStream.read(buffer, 0, bytesAvailable);
while (bytesRead > 0) {
dos.write(buffer, 0, bytesAvailable);
bytesAvailable = fileInputStream.available();
bytesAvailable = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bytesAvailable);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// close streams
Log.e(Tag, "File is written");
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
Log.e(Tag, "error: " + ex.getMessage(), ex);
}
catch (IOException ioe) {
Log.e(Tag, "error: " + ioe.getMessage(), ioe);
}
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(conn
.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
Log.e("Dialoge Box", "Message: " + line);
}
rd.close();
} catch (IOException ioex) {
Log.e("MediaPlayer", "error: " + ioex.getMessage(), ioex);
}
}
Php code on server side :
<?php
$target_path = "./upload/";
$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);
if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
echo "The file ". basename( $_FILES['uploadedfile']['name']).
" has been uploaded";
} else{
echo "There was an error uploading the file, please try again!";
}
?>
I think there is no correct answer for this question, PHP can be good as JSP or even ASP. Depends on your platform preference or if you are planning on having a tomcat vs apache server or even a microsoft iis server. Personally I think PHP/Apache is a good choice.
I've spent the last day or so trying to debug this issue and I'm out of ideas. Basically I have an Android app that is POSTing some data to a PHP/Apache web server. This code seems to work fine when I point it at my local test server. It also seems to work fine when I point it at my production server, but ONLY when I comment out the line conn.setChunkedStreamingMode(maxBufferSize);. Once that line is enabled, the post only works on my local test server, but when posting to the production server, the PHP $_FILES array is empty. I've tried passing numerous values to setChunkedStreamingMode (including 0 and 1024) but none of these seem to fix the problem.
At this point I'm assuming the issue has to do with the way the production server's PHP is configured, but as far as I can tell, all the important parameters on the server are the same as on my test instance. Additionally, they're both running the same version of Apache and PHP. My production server is run by Bluehost.
Here's the Java code I'm using to upload:
HttpURLConnection conn = null;
DataOutputStream dos = null;
DataInputStream inStream = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "***************************************************";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 212144; // 1024*1024 = 1MB. 212144 is a quarter MB.
FileInputStream fileInputStream = null;
try
{
// ------------------ CLIENT REQUEST
fileInputStream = new FileInputStream(new File(existingFileWithFullPath));
// open a URL connection to the Servlet
URL url = new URL(BACKUP_POST_URL);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Send in chunks (to avoid out of memory error)
conn.setChunkedStreamingMode(maxBufferSize);
// Don't use a cached copy.
conn.setUseCaches(false);
// Use a post method.
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="
+ boundary);
conn.setReadTimeout(200000); // 200 seconds...
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
+ fileName + "\"" + lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0)
{
try {
dos.write(buffer, 0, bufferSize);
} catch (OutOfMemoryError oome) {
Log.e(CommonStatic.LOG_NAME, "Out of memory error caught...");
oome.printStackTrace();
fileInputStream.close();
throw new Exception("Out Of Memory!");
}
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
fileInputStream.close();
dos.flush();
dos.close();
// close streams
Log.d(CommonStatic.LOG_NAME, "Backup file written to server successfully...");
}
catch (Exception ex)
{
Log.e(CommonStatic.LOG_NAME, "Backup File Upload Error: " + ex.getMessage(), ex);
throw new Exception (c.getString(R.string.SAVE_TO_CLOUD_ERROR));
}
And here's the PHP code I'm using on the other end to recieve:
$target = "userfiles/";
$target = $target . basename( $_FILES['uploadedfile']['name']);
if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target))
{
echo "SUCCESS";
}
else
{
echo "FAIL";
}
I stuck a print_r($_FILES); at the very beginning of the script to determine that $_FILES is empty on the production instance, but not on the test instance. Any ideas would be greatly appreciated.
Unfortunately I wasn't able to find a direct solution to this problem, but I was able to find a workaround. Instead of using conn.setChunkedStreamingMode I used conn.setFixedLengthStreamingMode, which I had tried before with no success. The key to getting conn.setFixedLengthStreamingMode to work is to pass it the full length of the data you are attempting to send (in this case the file), plus the length of the headers. Fortunately header length is usually fixed in code such as this, so once you figure out how big your header is (keeping in mind things like the filename, which gets sent in the header under Content-Disposition is also variable) you can just put it in as a fixed number. To figure out my header length, I ran the code first without specifying any length for the header. The error message I received back gave me an expected and an actual value for the number of bytes sent, which allowed me to calculate the header length.
So, I'm trying to upload a file to my PHP server. I found some code online which works, but I also need to include values for things like user authentication and where on the server the file should be uploaded. I am relatively new to HTTP communication and the code I found below uses terms/code that I have never heard of before, multipart/form-data Content-Type and Content-Disposition specifically. So if someone could tell me how to include the values I need, provide a different method entirely, or just explain those 3 terms to me like I'm five, I'd greatly appreciate it. Here's my code:
public static void upload(String path, String section, Context c){
Log.i("path", path);
HttpURLConnection conn = null;
DataOutputStream dos = null;
DataInputStream inStream = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1 * 1024 * 1024;
String responseFromServer = "";
String urlString = c.getString(R.string.server) + "upload.php";
try {
// ------------------ CLIENT REQUEST
FileInputStream fileInputStream = new FileInputStream(new File(
path));
// open a URL connection to the Servlet
URL url = new URL(urlString);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Don't use a cached copy.
conn.setUseCaches(false);
// Use a post method.
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
+ path + "\"" + lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// close streams
Log.e("Debug", "File is written");
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
Log.e("Debug", "error: " + ex.getMessage(), ex);
} catch (IOException ioe) {
Log.e("Debug", "error: " + ioe.getMessage(), ioe);
}
// ------------------ read the SERVER RESPONSE
try {
inStream = new DataInputStream(conn.getInputStream());
String str;
while ((str = inStream.readLine()) != null) {
Log.e("Debug", "Server Response " + str);
}
inStream.close();
} catch (IOException ioex) {
Log.e("Debug", "error: " + ioex.getMessage(), ioex);
}
}
**Edit: Just to be a little more clear, I would like it to where in my PHP script I could access values like $_REQUEST['path'] (which might = '/documents/' or something) as well as the actual file with $_FILES['uploadedfile']
String urlToSendRequest = "https://example.net";
String targetDomain = "example.net";
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpHost targetHost = new HttpHost(targetDomain, 80, "http");
HttpPost httpPost = new HttpPost(urlToSendRequest);
// Make sure the server knows what kind of a response we will accept
// httpPost.addHeader("Accept", "text/xml");
// Also be sure to tell the server what kind of content we are sending
httpPost.addHeader("Content-Type", "application/xml");
StringEntity entity = new StringEntity("<input>test</input>", "UTF-8");
entity.setContentType("application/xml");
httpPost.setEntity(entity);
HttpResponse response = httpClient.execute(httpPost, context);
Reader r = new InputStreamReader(response.getEntity().getContent());
Thank you in advance.
I'd like to upload some bitmap image from my android app.
but , I can't get it.
Could you recommend some solutions for it.
or collect my source code?
ByteArrayOutputStream bao = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, bao);
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(
"http://example.com/imagestore/post");
MultipartEntity entity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE );
byte [] ba = bao.toByteArray();
try {
entity.addPart("img", new StringBody(new String(bao.toByteArray())));
httppost.setEntity(entity);
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Execute HTTP Post Request
HttpResponse response = null;
try {
response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
}
use httpmime for uploading Image
try this
http://vikaskanani.wordpress.com/2011/01/11/android-upload-image-or-file-using-http-post-multi-part/
I found this solution really well created and 100% working even with amazon ec2, take a look into this link:
Uploading files to HTTP server using POST on Android (link deleted).
Compare to previous answer, this solution doesn't require to import huge library httpmime from Apache.
Copied text from original article:
This tutorial shows a simple way of uploading data (images, MP3s, text files etc.) to HTTP/PHP server using Android SDK.
It includes all the code needed to make the uploading work on the Android side, as well as a simple server side code in PHP to handle the uploading of the file and saving it. Moreover, it also gives you information on how to handle the basic autorization when uploading the file.
When testing it on emulator remember to add your test file to Android’s file system via DDMS or command line.
What we are going to do is set the appropriate content type of the request and include the byte array as the body of the post. The byte array will contain the contents of a file we want to send to the server.
Below you will find a useful code snippet that performs the uploading operation. The code includes also server response handling.
HttpURLConnection connection = null;
DataOutputStream outputStream = null;
DataInputStream inputStream = null;
String pathToOurFile = "/data/file_to_send.mp3";
String urlServer = "http://192.168.1.1/handle_upload.php";
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;
try
{
FileInputStream fileInputStream = new FileInputStream(new File(pathToOurFile) );
URL url = new URL(urlServer);
connection = (HttpURLConnection) url.openConnection();
// Allow Inputs & Outputs.
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
// Set HTTP method to POST.
connection.setRequestMethod("POST");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
outputStream = new DataOutputStream( connection.getOutputStream() );
outputStream.writeBytes(twoHyphens + boundary + lineEnd);
outputStream.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + pathToOurFile +"\"" + lineEnd);
outputStream.writeBytes(lineEnd);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// Read file
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0)
{
outputStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
outputStream.writeBytes(lineEnd);
outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// Responses from the server (code and message)
serverResponseCode = connection.getResponseCode();
serverResponseMessage = connection.getResponseMessage();
fileInputStream.close();
outputStream.flush();
outputStream.close();
}
catch (Exception ex)
{
//Exception handling
}
If you need to authenticate your user with a username and password while uploading the file, the code snippet below shows how to add it. All you have to do is set the Authorization headers when the connection is created.
String usernamePassword = yourUsername + “:” + yourPassword;
String encodedUsernamePassword = Base64.encodeToString(usernamePassword.getBytes(), Base64.DEFAULT);
connection.setRequestProperty (“Authorization”, “Basic ” + encodedUsernamePassword);
Let’s say that a PHP script is responsible for receiving data on the server side. Sample of such a PHP script could look like this:
<?php
$target_path = "./";
$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);
if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path))
{
echo "The file ". basename( $_FILES['uploadedfile']['name']).
" has been uploaded";
}
else
{
echo "There was an error uploading the file, please try again!";
}
?>;
Code was tested on Android 2.1 and 4.3. Remember to add permissions to your script on server side. Otherwise, the uploading won’t work.
chmod 777 uploadsfolder
Where uploadsfolder is the folder where the files are uploaded. If you plan to upload files bigger than default 2MB file size limit. You will have to modify the upload_max_filesize value in the php.ini file.
I'm trying to make a program that uploads a image to a webserver that accepts multipart file-uploads.
More specificly i want to make a http POST request to http://iqs.me that sends a file in the variable "pic".
I've made a lot of tries but i don't know if i've even been close. The hardest part seems to be to get a HttpURLConnection to make a request of the type POST. The response i get looks like it makes a GET.
(And i want to do this without any third party libs)
UPDATE: non-working code goes here (no errors but doesn't seem to do a POST):
HttpURLConnection conn = null;
BufferedReader br = null;
DataOutputStream dos = null;
DataInputStream inStream = null;
InputStream is = null;
OutputStream os = null;
boolean ret = false;
String StrMessage = "";
String exsistingFileName = "myScreenShot.png";
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;
String responseFromServer = "";
String urlString = "http://iqs.local.com/index.php";
try{
FileInputStream fileInputStream = new FileInputStream( new File(exsistingFileName) );
URL url = new URL(urlString);
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setUseCaches(false);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
dos = new DataOutputStream( conn.getOutputStream() );
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"pic\";" + " filename=\"" + exsistingFileName +"\"" + lineEnd);
dos.writeBytes(lineEnd);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0){
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
fileInputStream.close();
dos.flush();
dos.close();
}catch (MalformedURLException ex){
System.out.println("Error:"+ex);
}catch (IOException ioe){
System.out.println("Error:"+ioe);
}
try{
inStream = new DataInputStream ( conn.getInputStream() );
String str;
while (( str = inStream.readLine()) != null){
System.out.println(str);
}
inStream.close();
}catch (IOException ioex){
System.out.println("Error: "+ioex);
}
Two things:
Make sure you call setRequestMethod to set the HTTP request to be a POST. You should be warned that doing multipart POST requests by hand is difficult and error-prone.
If you're running on *NIX, the tool netcat is very useful for debugging this stuff. Run
netcat -l -p 3000
and point your program to port 3000; you'll see exactly what the program is sending (Control-C to close it afterwards).
I have used this and found it useful in multipart file upload
File f = new File(filePath);
PostMethod filePost = new PostMethod(url);
Part[] parts = { new FilePart("file", f) };
filePost.setRequestEntity(new MultipartRequestEntity(parts,
filePost.getParams()));
HttpClient client = new HttpClient();
status = client.executeMethod(filePost);