Develop Reference

How to send XML-RPC request with HTTPS?

I am new to XML-RPC and may be my question is silly but I can't find any information to help me for that...
So here it is : I am using this java code to send a XML file through a XML-RPC request using HTTP.
public static void sendXML(String file, String host, String port, String url) throws IOException{
Socket socket = new Socket(host, Integer.parseInt(port));
OutputStream out = socket.getOutputStream();
InputStream in = socket.getInputStream();
StringBuffer header = new StringBuffer();
header.append("POST "+url+" HTTP/1.0\n");
header.append("Content-Type: text/xml\n");
header.append("Content-Length: "+(new File(file).length()+2)+"\n");
header.append("\n");
byte[] buffer = header.toString().getBytes("UTF-8");
out.write(buffer);
InputStream src = new FileInputStream(file);
buffer = new byte[1024];
int b = 0;
while((b = src.read(buffer)) >= 0){
out.write(buffer, 0, b);
}
buffer = "\n\n".getBytes("UTF-8");
out.write(buffer);
out.close();
src.close();
in.close();
out.flush();
socket.close();
}
In this code, the XML file is already created, containing the method called and all the parameters.
This solution works fine but I am asking to make it compatible for a HTTPS protocol.
Do I need to only change the line
header.append("POST "+url+" HTTP/1.0\n");
in
header.append("POST "+url+" HTTPS/1.0\n");
?
Or should I use the Apache library https://ws.apache.org/xmlrpc/client.html ?
Or may be is there any simpler solution in java language ?
Thank you all for your help

Downloading a file created in server using Java

I am trying to download a file from a given URL. The URL is not a direct file URL. When this URL is provided in browser manually, we get a prompt for download/save.
For example, http://www.my-domain.com/download/type/salary/format/excel
I have no issues in the URL which has the file name directly in the URL. In the above URL, based on the format and type, server generates the file.
In Java I am trying to download the file using the below code. The file is created, but the content is just the domain content and not the actual excel data.
URL url = new URL("http://www.my-domain.com/download/type/salary/format/excel");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
float totalDataRead = 0;
BufferedInputStream in = new BufferedInputStream(connection.getInputStream());
FileOutputStream fos = new FileOutputStream("c:\\test.xls");
BufferedOutputStream bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int i = 0;
while ((i = in.read(data, 0, 1024)) >= 0) {
totalDataRead = totalDataRead + i;
bout.write(data, 0, i);
}
bout.close();
in.close();

The content is whatever the server sent for that URL. You can't do anything about that from the client end. If it contained Javascript for example it won't get executed.

When you want to solve a problem you have to use the adequate tools to get the thing done. The adequate tools can be found at poi.apache.org. Have a look at Apache POI.

InputStream - Dealing with network changes

I'm downloading an attachment using Java mail API and whenever there is a small change in network state, my app gets stuck and I have to restart it, it's not even crashing.
This is the code snippet:
InputStream is = bodyPart.getInputStream();
String fileName = MimeUtility.decodeText(bodyPart.getFileName());
// Downloading the file
File f = new File(Constants.getPath() + fileName);
try {
FileOutputStream fos;
fos = new FileOutputStream(f);
byte[] buf = new byte[8*1024];
int bytesRead;
while ((bytesRead = is.read(buf)) != -1) {
fos.write(buf, 0, bytesRead);
}
fos.close();
}
What is the best way to deal with this issue? Thanks.

Your application is stuck. The solution to that is to set a read timeout, as discussed in this question. If the timeout occurs a SocketTimeoutException will be thrown.

Need help optimising bufferedReader output

I am sending a file to the browser in a servlet. The highest JDK I can use is 1.4.2, and I also have to retrieve the file via a URL. I am also trying to use "guessContentTypeFromStream", but I keep getting null which raises an exception when used in the code sample below. I currently have to hard code or work out the content-type myself.
What I would like to know is, how I can re-factor this code so the file transmission is as fast as possible and also use guessContentTypeFromStream ? (Note "res" is HttpServletResponse).
URL servletUrl = new URL(sFileURL);
URLConnection conn = servletUrl.openConnection();
int read;
BufferedInputStream bis = new BufferedInputStream(conn.getInputStream());
String sContentType =conn.guessContentTypeFromStream(conn.getInputStream());
res.setContentType(sContentType);
//res.setContentType("image/jpeg");
PrintWriter os = res.getWriter();
while((read = bis.read()) != -1){
os.write(read);
}
//Clean resources
os.flush();

This is how you normally read/writes data.
in = new BufferedInputStream(socket.getInputStream(), BUFFER_SIZE);
byte[] dataBuffer = new byte[1024 * 16];
int size = 0;
while ((size = in.read(dataBuffer)) != -1) {
out.write(dataBuffer, 0, size);
}

URL Connection (FTP) in Java - Simple Question

I have a simple question. I'm trying to upload a file to my ftp server in Java.
I have a file on my computer, and I want to make a copy of that file and upload it. I tried manually writing each byte of the file to the output stream, but that doesn't work for complicated files, like zip files or pdf files.
File file = some file on my computer;
String name = file.getName();
URL url = new URL("ftp://user:password#domain.com/" + name +";type=i");
URLConnection urlc = url.openConnection();
OutputStream os = urlc.getOutputStream();
//then what do I do?
Just for kicks, here is what I tried to do:
OutputStream os = urlc.getOutputStream();
BufferedReader br = new BufferedReader(new FileReader(file));
String line = br.readLine();
while(line != null && (!line.equals(""))) {
os.write(line.getBytes());
os.write("\n".getBytes());
line = br.readLine();
}
os.close();
For example, when I do this with a pdf and then try and open the pdf that I run with this program, it says an error occurred when trying to open the pdf. I'm guessing because I am writing a "\n" to the file? How do I copy the file without doing this?

Do not use any of the Reader or Writer classes when you're trying to copy the byte-for-byte exact contents of a binary file. Use these only for plain text! Instead, use the InputStream and OutputStream classes; they do not interpret the data at all, while the Reader and Writer classes interpret the data as characters. For example
OutputStream os = urlc.getOutputStream();
FileInputStreamReader fis = new FileInputStream(file);
byte[] buffer = new byte[1000];
int count = 0;
while((count = fis.read(buffer)) > 0) {
os.write(buffer, 0, count);
}
Whether your URLConnection usage is correct here, I don't know; using Apache Commons FTP (as suggested elsewhere) would be an excellent idea. Regardless, this would be the way to read the file.

Use a BufferedInputStream to read and BufferedOutputStream to write. Take a look at this post: http://www.ajaxapp.com/2009/02/21/a-simple-java-ftp-connection-file-download-and-upload/
InputStream is = new FileInputStream(localfilename);
BufferedInputStream bis = new BufferedInputStream(is);
OutputStream os =m_client.getOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(os);
byte[] buffer = new byte[1024];
int readCount;
while( (readCount = bis.read(buffer)) > 0) {
bos.write(buffer, 0, readCount);
}
bos.close();

FTP usually opens another connection for data transfer.
So I am not convinced that this approach with URLConnection is going
to work.
I highly recommend that you use specialized ftp client. Apache commons
may have one.
Check this out
http://commons.apache.org/net/api/org/apache/commons/net/ftp/FTPClient.html