I am trying to write an image over an HttpURLConnection.
I know how to write text but I am having real problems trying
to write an image
I have succeeded in writing to the local HD using ImageIO:
But I am trying to write Image by ImageIO on url and failed
URL url = new URL(uploadURL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setUseCaches(false);
connection.setRequestProperty("Content-Type", "multipart/form-data;
boundary=" + boundary);
output = new DataOutputStream(connection.getOutputStream());
output.writeBytes("--" + boundary + "\r\n");
output.writeBytes("Content-Disposition: form-data; name=\"" + FIELD_NAME + "\";
filename=\"" + fileName + "\"\r\n");
output.writeBytes("Content-Type: " + dataMimeType + "\r\n");
output.writeBytes("Content-Transfer-Encoding: binary\r\n\r\n");
ImageIO.write(image, imageType, output);
the uploadURL is the url to an asp page on the server which will upload the image with the file name given in "content-Disposition: part.
now when I send this then asp page find the request and find the name of file. but does not find the file to be uploaded.
The problem is that when writing by ImageIO on URL what will the name of the file on which the ImageIO is writing,
So please help me how ImageIO will write an image on URLConnection and how can I know the name of the file which I have to use in the asp page to upload the file
Thanks for taking the time to read this post
Dilip Agarwal
First I believe that you should call io.flush() and then io.close() after writing image.
Second content type seems strange for me. It seems that you are trying to submit form while it is actually image. I do not know what does your asp expect but typically when I write code that should transfer file over HTTP I send appropriate content type, e.g. image/jpeg.
Here is for example code snippet I extracted from one small utility that I wrote and I am using during my current work:
URL url = new URL("http://localhost:8080/handler");
HttpURLConnection con = (HttpURLConnection)url.openConnection();
con.setDoInput(true);
con.setDoOutput(true);
con.setUseCaches(false);
con.setRequestProperty("Content-Type", "image/jpeg");
con.setRequestMethod("POST");
InputStream in = new FileInputStream("c:/temp/poc/img/mytest2.jpg");
OutputStream out = con.getOutputStream();
copy(in, con.getOutputStream());
out.flush();
out.close();
BufferedReader r = new BufferedReader(new InputStreamReader(con.getInputStream()));
// obviously it is not required to print the response. But you have
// to call con.getInputStream(). The connection is really established only
// when getInputStream() is called.
System.out.println("Output:");
for (String line = r.readLine(); line != null; line = r.readLine()) {
System.out.println(line);
}
I used here method copy() that I took from Jakarta IO utils. Here is the code for reference:
protected static long copy(InputStream input, OutputStream output)
throws IOException {
byte[] buffer = new byte[12288]; // 12K
long count = 0L;
int n = 0;
while (-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
count += n;
}
return count;
}
Obviously the server side must be ready to read the image content directly from POST body.
I hope this helps.
The OP seems lost into oblivion but for the benefit of Mister Kite :
// main method
URL url = new URL(uploadURL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true); // triggers "POST"
// connection.setDoInput(true); // only if needed
connection.setUseCaches(false); // dunno
final String boundary = Long.toHexString(System.currentTimeMillis());
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary="
+ boundary);
output = new DataOutputStream(connection.getOutputStream());
try {
// image must be a File instance
flushMultiPartData(image, output, boundary);
} catch (IOException e) {
System.out.println("IOException in flushMultiPartData : " + e);
return;
}
// ...
private void flushMultiPartData(File file, OutputStream serverOutputStream,
String boundary) throws FileNotFoundException, IOException {
// SEE https://stackoverflow.com/a/2793153/281545
PrintWriter writer = null;
try {
// true = autoFlush, important!
writer = new PrintWriter(new OutputStreamWriter(serverOutputStream,
charsetForMultipartHeaders), true);
appendBinary(file, boundary, writer, serverOutputStream);
// End of multipart/form-data.
writer.append("--" + boundary + "--").append(CRLF);
} finally {
if (writer != null) writer.close();
}
}
private void appendBinary(File file, String boundary, PrintWriter writer,
OutputStream output) throws FileNotFoundException, IOException {
// Send binary file.
writer.append("--" + boundary).append(CRLF);
writer.append(
"Content-Disposition: form-data; name=\"binaryFile\"; filename=\""
+ file.getName() + "\"").append(CRLF);
writer.append("Content-Type: "
+ URLConnection.guessContentTypeFromName(file.getName()))
.append(CRLF);
writer.append("Content-Transfer-Encoding: binary").append(CRLF);
writer.append(CRLF).flush();
InputStream input = null;
try {
input = new FileInputStream(file);
byte[] buffer = new byte[1024];
for (int length = 0; (length = input.read(buffer)) > 0;) {
output.write(buffer, 0, length);
}
output.flush(); // Important! Output cannot be closed. Close of
// writer will close output as well.
} finally {
if (input != null) try {
input.close();
} catch (IOException logOrIgnore) {}
}
writer.append(CRLF).flush(); // CRLF is important! It indicates end of
// binary boundary.
}
You may want to add Gzip compression - see file corrupted when I post it to the servlet using GZIPOutputStream for a working class with or without Gzip. The ImageIO has no place here - just write the bytes past the wire and use ImageIO to your heart's content on the server. Based on #BalusC answer
Related
private void uploadDocToSharePoint(String token, Resource resource, String folderName) {
try {
String uploadUrl = Utils.SHARE_POINT_DOMAIN + "_api/web/getfolderbyserverrelativeurl('" + folderName + "')/files/add(url='" + resource.getFilename() + "', overwrite=true)";
URL url = new URL(uploadUrl);
HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
// Set Header
httpConn.setDoOutput(true);
httpConn.setDoOutput(true);
httpConn.setRequestMethod("POST");
httpConn.setRequestProperty("Authorization", "Bearer " + token);
httpConn.setRequestProperty("accept", "application/json; odata=verbose");
httpConn.setRequestProperty("Content-Type", "application/xml");
OutputStream os = httpConn.getOutputStream();
OutputStreamWriter osw = new OutputStreamWriter(os, StandardCharsets.UTF_8);
osw.write("Just Some Text");
osw.flush();
osw.close();
os.close(); //don't forget to close the OutputStream
httpConn.connect();
System.out.println(httpConn.getResponseCode());
System.out.println(httpConn.getResponseMessage());
String result;
BufferedInputStream bis = new BufferedInputStream(httpConn.getInputStream());
ByteArrayOutputStream buf = new ByteArrayOutputStream();
int result2 = bis.read();
while(result2 != -1) {
buf.write((byte) result2);
result2 = bis.read();
}
result = buf.toString();
System.out.println(result);
} catch (Exception e) {
System.out.println("Error while reading file: " + e.getMessage());
}
}
httpConn.getResponseCode() is 400 and httpConn.getResponseMessage() is Bad Request.
I have tested this request with the URL generated in this class on Postman.
it works correctly.
so I am sure about url and token is correct.
It creates an Empty file successfully.
But as I mentioned the response status is 400 and Bad Request.
I am not sure what is wrong with the following class
Sharepoint guide here
My class copied from here
screenshot here
Pls follow Sharepoint guide here
Hi I have seen many sample codes working for sending a file in multipart/form-data in java.
But they have used both Writer and an OutputStream.
Why can't they use just use one of them?
Here is the sample code they have sent
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
public class MainClass_External2 {
public static void main(String[] args){
try{
// Connect to the web server endpoint
URL serverUrl =
new URL("http://posttestserver.com/post.php?dir=example");
HttpURLConnection urlConnection = (HttpURLConnection)serverUrl.openConnection();
String boundaryString = "----SomeRandomText";
String fileUrl = "abc.txt";
File logFileToUpload = new File(fileUrl);
// Indicate that we want to write to the HTTP request body
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.addRequestProperty("Content-Type","multipart/form-data; boundary=" + boundaryString);
// Indicate that we want to write some data as the HTTP request body
urlConnection.setDoOutput(true);
OutputStream outputStreamToRequestBody = urlConnection.getOutputStream();
BufferedWriter httpRequestBodyWriter =
new BufferedWriter(new OutputStreamWriter(outputStreamToRequestBody));
// Include value from the myFileDescription text area in the post data
httpRequestBodyWriter.write("\n\n--" + boundaryString + "\n");
httpRequestBodyWriter.write("Content-Disposition: form-data; name=\"myFileDescription\"");
httpRequestBodyWriter.write("\n\n");
httpRequestBodyWriter.write("Log file for 20150208");
// Include the section to describe the file
httpRequestBodyWriter.write("\n--" + boundaryString + "\n");
httpRequestBodyWriter.write("Content-Disposition: form-data;"
+ "name=\"myFile\";"
+ "filename=\""+ logFileToUpload.getName() +"\""
+ "\nContent-Type: text/plain\n\n");
httpRequestBodyWriter.flush();
// Write the actual file contents
FileInputStream inputStreamToLogFile = new FileInputStream(logFileToUpload);
int bytesRead;
byte[] dataBuffer = new byte[1024];
while((bytesRead = inputStreamToLogFile.read(dataBuffer)) != -1){
outputStreamToRequestBody.write(dataBuffer, 0, bytesRead);
}
// Mark the end of the multipart http request
httpRequestBodyWriter.write("\n--" + boundaryString + "--\n");
httpRequestBodyWriter.flush();
// Close the streams
outputStreamToRequestBody.close();
httpRequestBodyWriter.close();
// Read response from web server, which will trigger the multipart HTTP request to be sent.
BufferedReader httpResponseReader =
new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String lineRead;
while((lineRead = httpResponseReader.readLine()) != null) {
System.out.println(lineRead);
}
}catch (Exception e){
e.printStackTrace();
}
}
}
Basically, the response contains both text and binary data, so using both a Writer and an OutputStream makes perfect sense.
The writer just wraps the output stream, and is used to write text. The output stream itself is used to write the binary data.
Why can't they use just use one of them?
Using just an OutputStream would make it more painful to write the text. Using just a Writer would be inappropriate when binary data needs to be written.
I have the following post code for Ruby Sinatra to upload image files :
post "/upload" do
File.open("public/uploads/" + params["image"][:filename], "wb") do |f|
f.write(params["image"][:tempfile].read)
end
end
And the following Java codes to upload the image file to example.com/upload :
private static String boundary;
private static final String LINE_FEED = "\r\n";
private static HttpURLConnection httpConn;
private static OutputStream outputStream;
private static PrintWriter writer;
public static void upload(String requestURL, String fieldName, File
uploadFile) throws IOException {
boundary = "===" + System.currentTimeMillis() + "===";
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoOutput(true);
httpConn.setDoInput(true);
httpConn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
outputStream = httpConn.getOutputStream();
writer = new PrintWriter(new OutputStreamWriter(outputStream, "UTF-8"), true);
String fileName = uploadFile.getName();
writer.append("--" + boundary).append(LINE_FEED);
writer.append("Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + fileName + "\"").append(LINE_FEED);
writer.append("Content-Type: "+ URLConnection.guessContentTypeFromName(fileName)).append(LINE_FEED);
writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
writer.append(LINE_FEED).flush();
FileInputStream inputStream = new FileInputStream(uploadFile);
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
inputStream.close();
writer.append("--" + boundary + "--").append(LINE_FEED);
writer.close();
httpConn.getInputStream();
httpConn.disconnect();
}
File uploadFile = new File("C:/myimage.png");
upload("http://www.example.com/upload", "image", uploadFile);
And my website is hosted at heroku .
After calling upload(), the image file is successfully uploaded, and i can access to it in example.com/upload/myimage.png
But the problem is : After some hours, when i check the url to see myimage.png, i got "Not Found" error ( 404 error in heroku logs )
Any ideas ?
Sorry for my bad english :|
You should not store files to heroku's local file system. From their docs:
Ephemeral filesystem
Each dyno gets its own ephemeral filesystem, with
a fresh copy of the most recently deployed code. During the dyno’s
lifetime its running processes can use the filesystem as a temporary
scratchpad, but no files that are written are visible to processes in
any other dyno and any files written will be discarded the moment the
dyno is stopped or restarted.
Instead of storing files locally it is recommended to upload files to AWS S3 or other cloud storage systems.
This is the method I have in my java application. It is reading the bytes correctly, I have logged to see if it was. The problem is that the php is not realizing the data is there. I have tested and the .php reads that $_POST is set, but is empty.
public void screenshot(BufferedImage screenshot) {
try {
ImageIO.write(screenshot, "png",
new File(Environment.getStorageDirectory().toString()
.concat(File.separator + SCRIPT_NAME + ".png")));
HttpURLConnection httpUrlConnection;
OutputStream outputStream;
BufferedInputStream fileInputStream;
BufferedReader serverReader;
int totalBytes;
String response = "";
String serverResponse = "";
String localFileName = Environment.getStorageDirectory().toString()
.concat(File.separator + SCRIPT_NAME + ".png");
// Establish a connection
httpUrlConnection = (HttpURLConnection) new URL(
"http://www.scripted.it/scriptoptions/utils/saveScreenshot.php?user="
+ SupraCrafter.statHandler.getUser())
.openConnection();
httpUrlConnection.setDoOutput(true);
httpUrlConnection.setDoInput(true);
httpUrlConnection.setRequestMethod("POST");
httpUrlConnection.setRequestProperty("Content-type",
"application/x-www-form-urlencoded");
outputStream = httpUrlConnection.getOutputStream();
// Buffered input stream
fileInputStream = new BufferedInputStream(new FileInputStream(
localFileName));
// Get the size of the image
totalBytes = fileInputStream.available();
// Loop through the files data
for (int i = 0; i < totalBytes; i++) {
// Write the data to the output stream
outputStream.write(fileInputStream.read());
}
// Close the output stream
outputStream.close();
// New reader to get server response
serverReader = new BufferedReader(new InputStreamReader(
httpUrlConnection.getInputStream()));
// Read the servers response
serverResponse = "";
while ((response = serverReader.readLine()) != null) {
serverResponse = serverResponse + response;
}
System.out.println(serverResponse);
// Close the buffered reader
serverReader.close();
} catch (Exception e) {
e.printStackTrace();
}
try {
URL url = new URL(
"http://scripted.it/scriptoptions/utils/setScreenshotStatus.php?user="
+ SupraCrafter.statHandler.getUser() + "&pass="
+ SupraCrafter.statHandler.getPass() + "&script="
+ SCRIPT_NAME + "&status=1");
BufferedReader in = new BufferedReader(new InputStreamReader(
url.openStream()));
in.close();
} catch (MalformedURLException e) {
} catch (IOException e) {
}
}
Here is the .php file:
<?
// Config
$uploadBase = "../screenshots/";
$uploadFilename = $_GET['user'] . ".png";
$uploadPath = $uploadBase . $uploadFilename;
// Upload directory
if(!is_dir($uploadBase))
mkdir($uploadBase);
// Grab the data
$incomingData = file_get_contents('php://input');
// Valid data?
if(!$incomingData)
die("No input data");
// Write to disk
$fh = fopen($uploadPath, 'w') or die("Error opening file");
fwrite($fh, $incomingData) or die("Error writing to file");
fclose($fh) or die("Error closing file");
echo "Success";
?>
It always echos 'no input data.'
You are not encoding the content with application/x-www-form-urlencoded. You should not simply copy the bytes into the HTTP payload, but instead encode it correctly.
application/x-www-form-urlencoded is not the only possible way of encoding it, multipart/form-data is another common choice. Both are supported by almost all webservers, and as a consequence by PHP.
A tutorial on how to encode using Java is here : http://www.devx.com/Java/Article/17679
Why don't you use Apache's HttpClient or similar library that already do that tedious work for you?
Apache HttpClient : http://hc.apache.org/httpcomponents-client-ga/
I want to make a POST by using HttpURLConnection.
I am trying this in 2 ways, but I always get an excetion when doing: conn.getOutputStream();
The exception I get in both cases is:
java.net.SocketException: Operation timed out: connect:could be due to
invalid address
function1:
public void makePost(String title, String comment, File file) {
try {
URL servlet = new URL("http://" + "www.server.com/daten/web/test/testupload.nsf/upload?CreateDocument");
HttpURLConnection conn=(HttpURLConnection)servlet.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
String boundary = "---------------------------7d226f700d0";
conn.setRequestProperty("Content-type","multipart/form-data; boundary=" + boundary);
//conn.setRequestProperty("Referer", "http://127.0.0.1/index.jsp");
conn.setRequestProperty("Cache-Control", "no-cache");
OutputStream os = conn.getOutputStream(); //exception throws here!
DataOutputStream out = new DataOutputStream(os);
out.writeBytes("--" + boundary + "\r\n");
writeParam(INPUT_TITLE, title, out, boundary);
writeParam(INPUT_COMMENT, comment, out, boundary);
writeFile(INPUT_FILE, file.getName(), out, boundary);
out.flush();
out.close();
InputStream stream = conn.getInputStream();
BufferedInputStream in = new BufferedInputStream(stream);
int i = 0;
while ((i = in.read()) != -1) {
System.out.write(i);
}
in.close();
} catch (Exception e) {
e.printStackTrace();
}
}
or function 2:
public void makePost2(String title, String comment, File file) {
File binaryFile = file;
String boundary = Long.toHexString(System.currentTimeMillis()); // Just generate some unique random value.
URLConnection connection = null;
try {
connection = new URL("http://" + "www.server.com/daten/web/test/testupload.nsf/upload?CreateDocument").openConnection();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
PrintWriter writer = null;
try {
OutputStream output = connection.getOutputStream(); //exception throws here
writer = new PrintWriter(new OutputStreamWriter(output, CHARSET), true); // true = autoFlush, important!
// Send normal param.
writer.println("--" + boundary);
writer.println("Content-Disposition: form-data; name=\""+ INPUT_TITLE +"\"");
writer.println("Content-Type: text/plain; charset=" + CHARSET);
writer.println();
writer.println(title);
// Send binary file.
writer.println("--" + boundary);
writer.println("Content-Disposition: form-data; name=\""+ INPUT_FILE +"\"; filename=\"" + binaryFile.getName() + "\"");
writer.println("Content-Type: " + URLConnection.guessContentTypeFromName(binaryFile.getName()));
writer.println("Content-Transfer-Encoding: binary");
writer.println();
InputStream input = null;
try {
input = new FileInputStream(binaryFile);
byte[] buffer = new byte[1024];
for (int length = 0; (length = input.read(buffer)) > 0;) {
output.write(buffer, 0, length);
}
output.flush(); // Important! Output cannot be closed. Close of writer will close output as well.
} catch (IOException e) {
e.printStackTrace();
} finally {
if (input != null) try { input.close(); } catch (IOException logOrIgnore) {}
}
writer.println(); // Important! Indicates end of binary boundary.
// End of multipart/form-data.
writer.println("--" + boundary + "--");
} catch (IOException e) {
e.printStackTrace();
} finally {
if (writer != null) writer.close();
}
}
The URL simply cannot be reached. Either the URL is wrong, or the DNS server couldn't resolve the hostname. Try a simple connect with a well-known URL to exclude one and other, e.g.
InputStream response = new URL("http://stackoverflow.com").openStream();
// Consume response.
Update as per the comments, you're required to use a proxy server for HTTP connections. You need to configure that in the Java side as well. Add the following lines before any attempt to connect to an URL.
System.setProperty("http.proxyHost", "proxy.example.com");
System.setProperty("http.proxyPort", "8080");
It suffices to do this only once during runtime.
See also:
Java guides - Networking and proxies
Without establishing the connection (which in this case requires 1 more step to be performed ie connect), transfer is not possible. connect() should be called after the connection is configured (ie after being done with the set***() on the connection).
What is missing is:
conn.connect();