How can I send XML from a Java application and print it with PHP on the server, using HTTP POST?

Usually when I get POST data it's send from a HTML form and the parameters has names, i.e. from <input type="text" name="yourname" />, then I can receive and print this data with php echo $_POST['yourname'];.

Now I am implementing a Java application that should POST data in XML format to a specified URL. I wrote a simple PHP page that I can try to POST data to, but the data is not printed. And since there is no name of any parameters I don't know how I should print it with PHP.

I have tried to send simple XML to the server and the server should respond with MESSAGE: <XML>, but it only response with MESSAGE:. What am I doing wrong?

Here is my PHP-code on the server:

<?php 
echo 'MESSAGE:';
print_r($_POST); ?>

And here is my Java code on the client:

String xmlRequestStatus = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>
    <test></test>";
String contentType = "text/xml";
String charset = "ISO-8859-1";
String request = null;
try {
    request = String.format("%s",
        URLEncoder.encode(xmlRequestStatus, charset));
} catch (UnsupportedEncodingException e1) {
    e1.printStackTrace();
}
URL url = null;
URLConnection connection = null;
OutputStream output = null;
InputStream response = null;
try {
    url = new URL("http://skogsfrisk.se/test/");
} catch (MalformedURLException e) {
    e.printStackTrace();
}

try {
    connection = url.openConnection();
    connection.setDoOutput(true);
    connection.setRequestProperty("Accept-Charset", charset);
    connection.setRequestProperty("Content-Type", contentType);
    output = connection.getOutputStream();
    output.write(request.getBytes("ISO-8859-1"));
    if(output != null) try { output.close(); } catch (IOException e) {}

    response = connection.getInputStream();
    ...
} catch (IOException e) {
    e.printStackTrace();
}