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How to guarantee a java POST request string / text to be UTF-8 encoding

I have a textmessage/string with letters like ä,ü,ß. I want everything to be UTF-8 encoded. When I write to a file or print the string to console, everything is fine. But when I want to send the same string to a web service, I get instead of ä,ü,ß the following �
I read the file from a Servlet.
Do I really have to use the following 2 lines to get a UTF-8 encoded text?
byte [] bray = text.getBytes("UTF-8");
text = new String(bray);
.
public static String readAsStream_UTF8(String filePathName){
String text ="";
InputStream input = Thread.currentThread().getContextClassLoader().getResourceAsStream("resources/"+filePathName);
if(input == null){
System.out.println("Inputstream null.");
}else{
InputStreamReader isr = null;
try {
isr = new InputStreamReader((InputStream)input, "UTF-8");
BufferedReader reader = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
String sCurrentLine;
while ((sCurrentLine = reader.readLine()) != null) {
sb.append(sCurrentLine);
}
text= sb.toString();
//it works only if I use the following 2 lines
byte [] bray = text.getBytes("UTF-8");
text = new String(bray);
} catch (Exception e1) {
e1.printStackTrace();
}
}
return text;
}
My sendPOST method looks something like the following:
String charset = "UTF-8";
OutputStreamWriter writer = null;
HttpURLConnection con = null;
String response_txt ="";
InputStream iss = null;
try {
URL url = new URL(urlService);
con = (HttpURLConnection)url.openConnection();
con.setDoOutput(true); //triggers POST
con.setDoInput(true);
con.setRequestMethod("POST");
con.setRequestProperty("accept-charset", charset);
//con.setRequestProperty("Content-Type", "application/soap+xml");
con.setRequestProperty("Content-Type", "application/soap+xml;charset=UTF-8");
writer = new OutputStreamWriter(con.getOutputStream());
writer.write(msg); //send POST data string
writer.flush();
writer.close();
What do I have to do to force the msg, that will be sent to the web service, to really be UTF-8 encoded.

If you know the encoding of the file which you want to send you don't need to convert it to an intermediary string. Simply copy its bytes to the output:
// inputstream to a UTF-8 encoded resource file
InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("resources/"+filePathName);
HttpURLConnection con = ...
// set contenttype and encoding
con.setRequestProperty("Content-Type", "application/soap+xml;charset=UTF-8");
// copy input to output
copy(in, con.getOutputStream());
using some copy function.
Additionally you could also set the Content-Length header to the size of the resource file.

how to make http get request in Android

I am new to android.So i can any one sho me how to make a http get request such as
GET /photos?size=original&file=vacation.jpg HTTP/1.1
Host: photos.example.net:80
Authorization: OAuth realm="http://photos.example.net/photos",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_token="nnch734d00sl2jdk",
oauth_nonce="kllo9940pd9333jh",
oauth_timestamp="1191242096",
oauth_signature_method="HMAC-SHA1",
oauth_version="1.0",
oauth_signature="tR3%2BTy81lMeYAr%2FFid0kMTYa%2FWM%3D"
in android(java)?

You're gonna want to get familiar with InputStreams and OutputStreams in Android, if you've done this in regular java before then its essentially the same thing. You need to open a connection with the request property as "GET", you then write your parameters to the output stream and read the response through an input stream. You can see this in my code below:
try {
URL url = null;
String response = null;
String parameters = "param1=value1&param2=value2";
url = new URL("http://www.somedomain.com/sendGetData.php");
//create the connection
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
//set the request method to GET
connection.setRequestMethod("GET");
//get the output stream from the connection you created
request = new OutputStreamWriter(connection.getOutputStream());
//write your data to the ouputstream
request.write(parameters);
request.flush();
request.close();
String line = "";
//create your inputsream
InputStreamReader isr = new InputStreamReader(
connection.getInputStream());
//read in the data from input stream, this can be done a variety of ways
BufferedReader reader = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
//get the string version of the response data
response = sb.toString();
//do what you want with the data now
//always remember to close your input and output streams
isr.close();
reader.close();
} catch (IOException e) {
Log.e("HTTP GET:", e.toString());
}

Retrieving imgur upload link after uploading an image through java

So I am using one of the imgur api examples for uploading an image but am stuck on how I retrieve the upload link to view the image.
This is what I have so far, and from what I can tell it uploads it but that itself is not very useful without getting a link to the upload.
This is what I have thus far.
String IMGUR_POST_URI = "http://api.imgur.com/2/upload.xml";
String IMGUR_API_KEY = "MY API KEY";
String file = "C:\\Users\\Shane\\Pictures\\Misc\\001.JPG";
try
{
// Creates Byte Array from picture
ByteArrayOutputStream baos = new ByteArrayOutputStream();
System.out.println("Writing image...");
ImageIO.write(getBufferedImageFromImage(Toolkit.getDefaultToolkit().createImage(file)), "png", baos);
URL url = new URL(IMGUR_POST_URI);
System.out.println("Encoding...");
//encodes picture with Base64 and inserts api key
String data = URLEncoder.encode("image", "UTF-8") + "=" + URLEncoder.encode(Base64.encodeBase64String(baos.toByteArray()).toString(), "UTF-8");
data += "&" + URLEncoder.encode("key", "UTF-8") + "=" + URLEncoder.encode(IMGUR_API_KEY, "UTF-8");
System.out.println("Connecting...");
// opens connection and sends data
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
System.out.println("Sending data...");
wr.write(data);
wr.flush();
}
catch(Exception e){e.printStackTrace();}

You should get back either an xml or json with the 'response' to the upload, according to the imgur docs.
I found this little snippet of code that is an example of getting the response after writing to a URL connection, maybe it will help you. This isn't specific to imgur but I think the code should be similar.
public static void main(String[] args) throws Exception {
String stringToReverse = URLEncoder.encode(args[1], "UTF-8");
URL url = new URL(args[0]);
URLConnection connection = url.openConnection();
connection.setDoOutput(true);
OutputStreamWriter out = new OutputStreamWriter(
connection.getOutputStream());
out.write("string=" + stringToReverse);
out.close();
BufferedReader in = new BufferedReader(
new InputStreamReader(
connection.getInputStream()));
String decodedString;
while ((decodedString = in.readLine()) != null) {
System.out.println(decodedString);
}
in.close();
}

How to send local .png to .php file on server using java application?

I have a local .png file that I want to send using POST data to a .php script that will save the data to a .png file on the server. How do I do this? Do I have to encode or something? All I have is a File and a way to POST data.
Here is how I am sending the .png:
public static byte[] imageToByte(File file) throws FileNotFoundException {
FileInputStream fis = new FileInputStream(file);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
try {
for (int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum);
}
} catch (IOException ex) {
}
byte[] bytes = bos.toByteArray();
return bytes;
}
public static void sendPostData(String url, HashMap<String, String> data)
throws Exception {
URL siteUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) siteUrl.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setDoInput(true);
DataOutputStream out = new DataOutputStream(conn.getOutputStream());
Set keys = data.keySet();
Iterator keyIter = keys.iterator();
String content = "";
for (int i = 0; keyIter.hasNext(); i++) {
Object key = keyIter.next();
if (i != 0) {
content += "&";
}
content += key + "=" + URLEncoder.encode(data.get(key), "UTF-8");
}
System.out.println(content);
out.writeBytes(content);
out.flush();
out.close();
BufferedReader in = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String line = "";
while ((line = in.readLine()) != null) {
System.out.println(line);
}
in.close();
}
The PHP script:
<?
// Config
$uploadBase = "../screenshots/";
$uploadFilename = $_GET['user'] . ".png";
$uploadPath = $uploadBase . $uploadFilename;
// Upload directory
if(!is_dir($uploadBase))
mkdir($uploadBase);
// Grab the data
$incomingData = $_POST['img'];
// Valid data?
if(!$incomingData || !isset($_POST['img']))
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";
?>

I must admit, I am surprised that you almost get the correct file. Actually, when you send a file using a browser, the form tag has an encoding defined: enctype="multipart/form-data". I don´t know how it works (It is defined in https://www.rfc-editor.org/rfc/rfc2388), but it includes encoding the file (for example, in Base64). Anyhow, you can forget about the internals if you use a http client library like the one from Apache HttpComponents

My minimalistic code works:
$body = file_get_contents('php://input');
$fh = fopen('file.txt', 'w') or die("Error opening fil
e");
fwrite($fh, $body) or die("Error writing to file");
fclose($fh)
curl --upload-file download.txt http://example.com/upload.php
However, set the method to PUT.

Image writing over URLConnection

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