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Receive image file through rest Api

How to receive an image file through Rest APIs. There is an option of MULTIPART_FORM_DATA which looks like it will send files in parts as in more than one request.
I want to receive images very fast on server. around 2 images per second.

Simply read image in a File and use Response class to build the response.
Response.ok(new File("myimage.jpg"), "image/jpeg").build();
There are other variations of the same.
Read the image using following.
URL url = new URL("http://localhost:8080/myimage/1");
URLConnection connection = url.openConnection();
input = connection.getInputStream();
byte[] buffer = new byte[1024];
int n = - 1;
OutputStream fos = new FileOutputStream("Output.jpg" );
while ( (n = input.read(buffer)) != -1)
{
fos.write(buffer, 0, n);
}
fos.close();
You can use Apache HTTP client to make it prettier.

Getting the jsp source code appended with the file content when I download files

I am working on a File upload/download functionality, in Java using Struts2 framework, where we are uploading to and downloading from a remote server path. All seems to work fine when I check the functionality at my local machine with a local path as the destined path from where i am downloading and to which am uploading the files of any format. The development environment has JBoss server.
But when I run the same over at the prod env, where the application is deployed in Weblogic server, files of .txt,.csv,.html (basically text format files) have my jsp source code appended to the file content.
Below is the code that I have used for downloading:
BufferedOutputStream bout=null;
FileInputStream inStream = null;
byte[] buffer = null;
try {
inStream = new FileInputStream(path+File.separator+filename);
buffer = new byte[8192];
String extension = "";
int pos = filename.lastIndexOf(".");
if (pos > 0)
extension = filename.substring(pos+1);
int bytesRead = 0, bytesBuffered = 0;
response.setContentType("application/octet-stream");
response.setHeader("content-disposition", "attachment; filename="+ filename);
bout = new BufferedOutputStream(response.getOutputStream());
while((bytesRead = fistrm.read(buffer)) > -1){
bout.write(buffer, 0, bytesRead);
bytesBuffered += bytesRead;
if(bytesBuffered > 1048576){
bytesBuffered = 0;
bout.flush();
}
}
} catch (IOException e) {
log.error(Logger.getStackTrace(e));
} finally {
if(bout!=null){
bout.flush();
bout.close();
}
if(inStream!=null)
inStream.close();
}
I have tried using different response content types with respect to the extension, but it was of no help.
Seems like the outputstream has the jsp source code in it even before writing from the inputstream.
Can anyone please suggest a solution and explain why is this happening ?

It is happening because you are writing directly in the outputstream, and then returning a struts result, that is your JSP. You are using an action as if it would be a servlet, which is not.
In Struts2, to achieve your goal, you need to use the Stream result type, as described in the following answers:
https://stackoverflow.com/a/16300376/1654265
https://stackoverflow.com/a/16900840/1654265
Otherwise, if you want to bypass the framework mechanisms and manually write to the outputStream by yourself (there are very rare cases in which it is useful, like downloading dynamically created ZIP), then you must return the NONE result.
Returning ActionSupport.NONE (or null) from an Action class method causes the results processing to be skipped. This is useful if the action fully handles the result processing such as writing directly to the HttpServletResponse OutputStream.
But I strongly suggest you to go with the Stream result, the standard way.

How to log inputstream to file in android and then parse it

I am receiving an InputStream from HttpUrlConnection (connection.getInputStream()), and I am parsing the input stream using DocumentBuilder (documenbtBuilder.parse(inputStream)). Before parsing, I want to write the received data to log file. When I do that, I get org.xml.sax.SAXParseException: Unexpected end of document Exception in the parse method. My code works fine if I don't write to file, but I need to log the data received.
Please find the code that writes to file below :
final InputStream input = connection.getInputStream();
writeLogInfo(input);
Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(input);
//Method that writes tito log file.
private void writeLogInfo(InputStream input){
OutputStream os = new FileOutputStream("mylogfile.txt");
byte[] buffer = new byte[1024];
int byteRead;
while((byteRead = input.read(buffer)) != -1){
os.write(buffer,0,byteRead);
}
os.flush();
os.close();
}
I suspect it is because of multiple use of InputStream, since the code works when I don't invode writeLogInfo(). I am not closing the inputstream anywhere in my code. What am I doing wrong here ?

When you are writing the content to a file, you are reaching the end of the inputstream.
So after that, when you are trying to parse, you get the exception.
You need to use mark and reset methods on the inputstream before passing it to documentbuilder.
Also, first you need to check if the input stream supports mark.
Here is the javadoc, for your reference
http://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html

Are you sure the size of the file is under 1024 bytes. If not why don't you put your "inputstream" to BufferredInputstream, and create the byte array..
BufferedInputStream bin= new BufferedInputStream(new DataInputStream(input));
byte[] buffer= new byte[bin.available()];
bin.read(buffer);
os.write(buffer);
......
......
bin.close();
......

Parsing PDF files hosted in web servers

I have used iText to parse pdf files. It works well on local files but I want to parse pdf files which are hosted in web servers like this one:
"http://protege.stanford.edu/publications/ontology_development/ontology101.pdf"
but I don't know how??? Could you please answer me how to do this task using iText or other libraries... thx

You need to download the bytes of the PDF file. You can do this with:
URL url = new URL("http://.....");
URLConnection conn = url.getConnection();
if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) { ..error.. }
if ( ! conn.getContentType().equals("application/pdf")) { ..error.. }
InputStream byteStream = conn.getInputStream();
try {
... // give bytes from byteStream to iText
} finally { byteStream.close(); }

Use the URLConnection class:
URL reqURL = new URL("http://www.mysite.edu/mydoc.pdf" );
URLConnection urlCon = reqURL.openConnection();
Then you can use the URLConnection method to retrieve the content. Easiest way:
InputStream is = urlCon.getInputStream();
byte[] b = new byte[1024]; //size of a buffer, can be any
int len;
while((len = is.read(b)) != -1){
//Store the content in preferred way
}
is.close();

Nothing to it. You can pass a URL directly into PdfReader, and let it handle the streaming for you:
URL url = new URL("http://protege.stanford.edu/publications/ontology_development/ontology101.pdf" );
PdfReader reader = new PDFReader( url );
The JavaDoc is your friend.

How to play .wav file from URL in web browser embed - Java

I want to play a .wav sound file in embed default media player in IE. Sound file is on some HTTP location. I am unable to sound it in that player.
Following is the code.
URL url = new URL("http://www.concidel.com/upload/myfile.wav");
URLConnection urlc = url.openConnection();
InputStream is = (InputStream)urlc.getInputStream();
fileBytes = new byte[is.available()];
while (is.read(fileBytes,0,fileBytes.length)!=-1){}
BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
out.write(fileBytes);
Here is embed code of HTML.
<embed src="CallStatesTreeAction.do?ivrCallId=${requestScope.vo.callId}&agentId=${requestScope.vo.agentId}" type="application/x-mplayer2" autostart="0" playcount="1" style="width: 40%; height: 45" />
If I write in FileOutputStream then it plays well
If I replace my code of getting file from URL to my local hard disk. then it also works fine.
I don't know why I am unable to play file from HTTP. And why it plays well from local hard disk.
Please help.

Make sure you set the correct response type. IE is very picky in that regard.
[EDIT] Your copy loop is broken. Try this code:
URL url = new URL("http://www.concidel.com/upload/myfile.wav");
URLConnection urlc = url.openConnection();
InputStream is = (InputStream)urlc.getInputStream();
fileBytes = new byte[is.available()];
int len;
while ( (len = is.read(fileBytes,0,fileBytes.length)) !=-1){
response.getOutputStream.write(fileBytes, 0, len);
}
The problem with your code is: If the data isn't fetched in a single call to is.read(), it's not appended to fileBytes but instead the first bytes are overwritten.
Also, the output stream which you get from the response is already buffered.