So basically I needed to upload an image to a web server using Java and PHP. Reading and writing simple data to and from a web server with Java is pretty easy really but when it comes to transferring files things get that little bit tougher. This is because when uploading files the content type of the HTTP request changes from plain text to multipart making it trickier. You could either write a whole load of extra code to deal with this or you could simply send the data over as plain text and then just let PHP deal with it. Here’s how it’s done.

The Java

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// Setup vars
HttpURLConnection httpUrlConnection;
OutputStream outputStream;
BufferedInputStream fileInputStream;
BufferedReader serverReader;
int totalBytes;
int bytesTrasferred;
String response = "";
String serverResponse = "";
String localFileName = "mypicture.jpg";
 
// Establish a connection
httpUrlConnection=(HttpURLConnection)new URL("http://www.example.com/upload.php").openConnection();
httpUrlConnection.setDoOutput(true);
httpUrlConnection.setRequestMethod("POST");
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());
	bytesTrasferred = i + 1;
}
 
// 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;
}
 
// Close the buffered reader
serverReader.close();
 
// Close the file input stream
fileInputStream.close();

The PHP

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// Config
$uploadBase = "img/";
$uploadFilename = time() . ".jpg";
$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";

And that’s all there is. By placing the PHP script above onto a suitable web server and then executing the Java code you’ll be able to quite easily and painlessly transfer images (or any other file types) from the desktop client to the web.

It’s quite simple really; a grid made up of diamonds pieced together to form the grid lines. Then, another simple isometric box shape placed somewhere in the middle. With this approach each grid section can be individually changed – this means that if enough time was spent it would be possible (and not all that difficult) to create a PHP + GD script which would generate random landscapes or cities. I quite like that idea, if only I had the time.

A few months ago I bought an Intel Mac Mini with the sole intention of developing applications for the iPhone. This meant I’d not only have to learn the Objective-C language but would also have to come to grips with Mac OSX – an OS which I’m not at all used to. After putting it off for a little while I’ve finally decided to take the leap and have begun the learning process.

To help this learning process I’ll try to document what particular things I’ve been looking at as I progress through what seems to be a very steep learning curve. Therefore from time to time I’ll post the occasional blog post explaining some of the things I’ve learnt with regards to Objective-C and iPhone application development. As well as being a great way for me to remember what I’ve been doing it may also be of some use to anyone else looking to take on this challenge.

Wish me luck!