I have a httpurlconnection code that is meant to post data to server. When I am trying to send small data it's ok but whene i try to send a base64 image string the string is not received properly at server. I have checked the base64 converted string from jpg and the encoding is ok. So, there is something wrong with the http process that's making the string corrupted. Initially I thought that probably it's the big images that's causing the problem but on using a very small image only transfers part of the image to server and the rest is corrupted.
Can somebody suggest me how can I send a base64 image string to server. My code is as below:
HttpURLConnection hpcon= (HttpURLConnection) Url.openConnection();
hpcon.setRequestMethod("POST");
hpcon.setConnectTimeout(5 * 1000);
hpcon.setDoOutput(true);
OutputStreamWriter osw= new OutputStreamWriter(hpcon.getOutputStream());
osw.write(data);
osw.close();
The data is something like:
key=YeP1r&nodeId=5&typeId=9&status=0&eventImage=imageString
Couldn't find a straight solution using HttpUrlConnection.
Used: httpClient from apache.
Actually pretty easy to use.
Last example multipart
Related
I am developing an Android application in which I am trying to send a simple array as a URL parameter, but it is not working properly. I am using a HTTP client and GET method. I have tried this in the following way:
StringBuilder sb = new StringBuilder();
sb.append(URLEncoder.encode(e.getKey(), "UTF-8")).append('=').append(URLEncoder.encode(e.getValue()+"", "UTF-8"));
where e.getValue() is ArrayList<Integers>
My URL params are appended %5B28%5D when I am sending [28]. If I don't use URL encoder then it goes as [28] But I want to use URL encoder. Am I doing anything wrong?
Your code is fine. this is how URL encoding works.
Seems like there issue in server at the time of decoding.
Debug the server for any possible issue with decoding.
also refer this answer for a better way of sending an array in get request.
I'm using an HttpsURLConnection to grab the only line in a text file hosted on Dropbox, as an update checker (for a Minecraft mod). The relevant code is below:
URL url = new URL(linkToVersionFile);
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
connection.setConnectTimeout(999);
int responseCode = connection.getResponseCode();
Normally, this works fine. Except, however, if the text in the file is "1.0.2". When it's 1.0.2, it returns the 460 response code, which I cant seem to find in any list of response codes. The accompanying response message is "Restricted" though.
If the file contains "1.0.1", "1.0.3", "1.1.2", "1.2.2" or even "2.0.2" it works just fine. Nothing changes but the 5 characters located in the file. The same thing happens if different files are used, and given the text "1.0.2", so it's not a corrupt file.
While I can get around it by either avoiding 1.0.2 and moving straight to 1.0.3, or writing it as "102" instead, it's just such an usual problem that I was wondering if anyone had an explanation :P
If more information or test results is required, let me know.
Thanks in advance :)
I am sending commands to a server using http, and I currently need to parse a response that the server sends back (I am sending the command via the command line, and the servers response appears in my browser).
There are a lot of resources such as this: Saving a web page to a file in Java, that clearly illustrate how to scrape a page such as cnn.com. However, since this is a response page that is only generated when the camera receives a specific command, my attempts to use the method described by Mike Deck (in the link above) have met with failure. (Specifically, when my program requests the page again the server returns a 401 error.)
The response from the server opens a new tab in my browser. Essentially, I need to know how to save the current web page using java, since reading in a file is probably the most simple way to approach this. Do any of you know how to do this?
TL;DR How do you save the current webpage to a webpage.html or webpage.txt file using java?
EDIT: I used Base64 from the Apache commons codec, which solved my 401 authentication issue. However, I am still getting a 400 error when I attempt to connect my InputStream (see below). Does this mean a connection isn't being established in the first place?
URL url = new URL ("http://"+ipAddress+"/axis-cgi/record/record.cgi?diskid=SD_DISK");
byte[] encodedBytes = Base64.encodeBase64("root:pass".getBytes());
String encoding = new String (encodedBytes);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoInput (true);
connection.setRequestProperty ("Authorization", "Basic " + encoding);
connection.connect();
InputStream content = (InputStream)connection.getInputStream();
BufferedReader in = new BufferedReader (new InputStreamReader (content));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
EDIT 2: Changing the request to a GET resolved the issue.
So while scrutinizing my code above, I decided to change
connection.setRequestMethod("POST");
to
connection.setRequestMethod("GET");
This solved my problem. In hindsight, I think the server was not recognizing the HTTP because it is not set up to handle the various trappings that come along with post.
I have a java application that sends text to a sql database on a server. Currently my java application takes the text, puts it into the url, then sends it to a php page on the server that takes it with GET and puts it in the database. that works fine to an extent, the problem is, that i need to be able to send lots of text, and i keep getting 414, uri to long errors. is there a better way to do this?
ok, i tried what you said, and read the tutorial, but something is not working. here is my code that i tried
public void submitText(String urls,String data) throws IOException{
URL url = new URL(urls);
URLConnection con = url.openConnection();
con.setRequestProperty("Content-Type", "text/plain; charset=utf-8");
con.setDoOutput(true);
OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream(), "UTF-8");
out.write(data);
out.flush();
}
submitText(server + "publicPB.php", "param=" + text);
here is my php code
$param = $_POST['param'];
$sql = "UPDATE table SET cell='{$param}' WHERE 1";
mysql_query($sql);
...
im pretty sure its not a problem with the php as the php worked fine with GET, and thats all i change with it, my problem i think is that im not 100% sure how to send data to it with the java
Use a POST instead of a GET and send the text as the request body. You can only pass so much data to a URL. E.g.:
// Assuming 'input' is a String and contains your text
URL url = new URL("http://hostname/path");
URLConnection con = url.openConnection();
con.setRequestProperty("Content-Type", "text/plain; charset=utf-8");
con.setDoOutput(true);
OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream(), "UTF-8");
out.write(input);
out.close();
See Reading from and Writing to a URLConnection for more details.
Why don't you use POST to send data across to PHP page? GET does have a smaller limit of content.
Use POST requests, which do not have content length limits.
POST requests do not have length content limits and are much secure than GET requests ;)
If using SQL Server I would look into leveraging BCP. You can write the file and call BCP from within Java, and it will send the information directly to your database.
I am attempting to have my android phone connect to my servlet and send it a certain image. The way I figured I would do this, is to use the copyPixelsToBuffer() function and then attempt to send this to the servlet through some output stream(similar to how I would do it in a normal stand alone java application). Will this way work? If so, what kind of stream do I use exactly? Should I just use DataOutputStream and just do something like the following:
ByteBuffer imgbuff;
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
bm.copyPixelsToBuffer(bm);
...code...
URLConnection sc = server.openConnection();
sc.setDoOutput(true);
DataOutputStream out = new DataOutputStream( sc.getOutputStream() );
out.write(imgbuff.array());
out.flush();
out.close();
Note: I understand that this may not be the proper way of connecting to a server using the Android OS but at the moment I'm working on just how to send the image, not the connection (unless this is relevant on how the image is sent).
If this is not a way you'd recommend sending the image to the servlet (I figured a byte buffer would be best but I could be wrong), how would you recommend this to be done?
Since a HttpServlet normally listens on HTTP requests, you'd like to use multipart/form-data encoding to send binary data over HTTP, instead of raw (unformatted) like that.
From the client side on, you can use URLConnection for this as outlined in this mini tutorial, but it's going to be pretty verbose. You can also use Apache HttpComponents Client for this. This adds however extra dependencies, I am not sure if you'd like to have that on Android.
Then, on the server side, you can use Apache Commons FileUpload to parse the items out of a multipart/form-data encoded request body. You can find a code example in this answer how the doPost() of the servlet should look like.
As to your code example: wrapping in the DataOutputStream is unnecessary. You aren't taking benefit of the DataOutputStream's facilities. You are just using write(byte[]) method which is already provided by the basic OutputStream as returned by URLConnection#getOutputStream(). Further, the Bitmap has a compress() method which you can use to compress it using a more standard and understandable format (PNG, JPG, etc) into an arbitrary OutputStream. E.g.
output = connection.getOutputStream();
// ...
bitmap.compress(CompressFormat.JPEG, 100, output);
Do this instead of output.write(bytes) as in your code.