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Is there a way to send GET request(s) over wifi to an ip-address instead of HttpUrlConnection

So basically I'm creating an android application and I want to communicate with a device that's on the same local network. The point is to request XML files and recieve them on my phone. Is there a way to do this using IP-addresses? Previously I've only done it using HttpUrlConnection (like the example below) I would love if someone brighter could enlighten me in this subject, thanks.
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.connect();
// read the response
InputStream in = new BufferedInputStream(conn.getInputStream());
response = convertStreamToString(in);

Try starting your ip address with the protocol identifier "http" E.g.
http://192.168.1.20/api/users

It turned out I was unable to do an HttpURLconnection at all and I had to do it in another way.

Server Timeout on Http GET on certain network

I am trying to make a get request in Java using HttpURLConnection. The response is 200 when I am on my home network but on the company nework i am getting a connect timed out error (SocketTimeoutException) I changed the timeout to be 20 seconds and I am still getting this error after a few seconds. The link is available when I view it in the browser on the same network that I am getting the timeout from the Java code, so I could it still be a firewall issue? Or something else? Here is my code:
String USER_AGENT = "Mozilla/5.0";
URL obj = new URL("http://jsonplaceholder.typicode.com/posts/1");
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setConnectTimeout(20000);
con.setRequestMethod("GET");
con.setRequestProperty("User-Agent", USER_AGENT);
int responseCode = con.getResponseCode();
System.out.println("GET Response Code :: " + responseCode);

This is typically an error produced by a firewall in your company's network. But if your browser is able to get to the internet, then your browser is using some proxy (likely the system proxy). So, you have to parametrize the JVM through the standard Java network properties to make it use the system proxy:
java -Djava.net.useSystemProxies=true ...
Or, alternatively, find out which are the system proxy parameters (host, port, user and password) and pass them to the JVM:
java -Dhttp.proxyHost=... -Dhttp.proxyPort=...

Java simple code: java.net.SocketException: Unexpected end of file from server

I wrote some simple code in Java, the method should connect to the website and return the BufferedReader.
private BufferedReader getConnection(String url_a) {
URL url;
try {
System.out.println("getting connection");
url = new URL(url_a);
HttpURLConnection urlConnection = (HttpURLConnection)
url.openConnection();
urlConnection.addRequestProperty("User-Agent",
"Mozilla/5.0 (X11; U; Linux i586; en-US; rv:1.7.3) Gecko/20040924"
+ "Epiphany/1.4.4 (Ubuntu)");
inStream = new InputStreamReader(urlConnection.getInputStream());
return new BufferedReader(inStream);
} catch (Exception ex) {
Logger.getLogger(Reader.class.getName()).log(Level.SEVERE, null, ex);
}
return null;
}
When I use it on my PC, it works fine but when I put .jar file on the server I get this error:
java.net.SocketException: Unexpected end of file from server
at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:718)
at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:579)
at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:715)
at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:579)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1322)
at dataconverter.Reader.getConnection(Reader.java.260)
Problem is quite strange because the exception isn't thrown each time, sometimes everything is OK and program works fine.
Has anybody got any ideas?

"Unexpected end of file" implies that the remote server accepted and closed the connection without sending a response. It's possible that the remote system is too busy to handle the request, or that there's a network bug that randomly drops connections.
It's also possible there is a bug in the server: something in the request causes an internal error, and the server simply closes the connection instead of sending a HTTP error response like it should. Several people suggest this is caused by missing headers or invalid header values in the request.
With the information available it's impossible to say what's going wrong. If you have access to the servers in question you can use packet sniffing tools to find what exactly is sent and received, and look at logs to of the server process to see if there are any error messages.

Summary
This exception is encountered when you are expecting a response, but the socket has been abruptly closed.
Detailed Explanation
Java's HTTPClient, found here, throws a SocketException with message "Unexpected end of file from server" in a very specific circumstance.
After making a request, HTTPClient gets an InputStream tied to the socket associated with the request. It then polls that InputStream repeatedly until it either:
Finds the string "HTTP/1."
The end of the InputStream is reached before 8 characters are read
Finds a string other than "HTTP/1."
In case of number 2, HTTPClient will throw this SocketException if any of the following are true:
The HTTP method is CONNECT
The HTTP method is POST and the client is set to streaming mode
Why would this happen
This indicates that the TCP socket has been closed before the server was able to send a response. This could happen for any number of reasons, but some possibilities are:
Network connection was lost
The server decided to close the connection
Something in between the client and the server (nginx, router, etc) terminated the request
Note: When Nginx reloads its config, it forcefully closes any in-flight HTTP Keep-Alive connections (even POSTs), causing this exact error.

I do get this error when I do not set the Authentication header or I set wrong credentials.

I would suggest using wire shark to trace packets. If you are using Ubuntu, sudo-apt get wireshark. Like Joni stated the only way to figure out whats going wrong is to follow the GET requests and their associated responses.
http://www.wireshark.org/download.html

In my case it was solved just passing proxy to connection. Thanks to #Andreas Panagiotidis.
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("<YOUR.HOST>", 80)));
HttpsURLConnection con = (HttpsURLConnection) url.openConnection(proxy);

In my case url contained wrong chars like spaces . Overall log your url and in some cases use browser.

Most likely the headers you are setting is incorrect or not acceptable.
Example:
connnection.setRequestProperty("content-type", "application/json");

I got this exception too. MY error code is below
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod(requestMethod);
connection.setRequestProperty("Content-type", "JSON");
I found "Content-type" should not be "JSON",is wrong!
I solved this exception by update this line to below
connection.setRequestProperty("Content-type", "application/json");
you can check up your "Content-type"

URL given have fileNotFoundException

I have the following code, it works totally fine on my local development server, but when I uploaded to the deployment server, I always hit file not found Exception
String urlStr = "http://" + getContext().getRequest().getServerName() +
getContext().getServletContext().getContextPath() + "test.action";
URL url = new URL(urlStr);
InputStream input = url.openStream(); //Error always occurs here, it gives me the correct URL but it says file not found.
Can anyone help me with this?

Because its a HTTP URL the correct way would be as follows.
String urlStr = "http://" + getContext().getRequest().getServerName() +
getContext().getServletContext().getContextPath() + "test.action";
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
if (conn.getResponseCode() == HttpURLConnection.HTTP_ACCEPTED) {
InputStream input = conn.getInputStream();
}

I think that #deadlock's comments is probably the key to solving this.
You are getting a FileNotFoundException because the remote server is sending a 404 Not Found response. The most likely explanation is that you are attempting to connect using the wrong URL. Print out the URL string before you try to connect.
All the evidence is pointing to the fact that the server is sending "404 Not Found" responses ... for both versions of the code. This normally means that your URL is wrong. But it is also possible for it to be other things:
You may be using different proxies in the Java and browser cases, resulting in the Java case reaching some server that doesn't understand the URL.
It is conceivable that the server is implementing some anti web scraping mechanism, and sending you 404 responses `cos this thinks (rightly) that your requests aren't coming from a web browser,

HttpURLConnection returns 503 error when accessed through proxy

I am working on creating a Video sitemap for a site that has hosted videos on Brightcove video cloud. In order to get all the video information from the site, Brightcove suggests to read the response from their url of following form
http://api.brightcove.com/services/library?token="+accountToken+"&page_size=1&command=find_all_videos&output=JSON&get_item_count=true
the output of the url is in JSON, where accountToken is just an identifier of the account.
When I hit the above url with Token in the browser, it gives me the correct response.
I wrote below program snippet to read from that url
URL jsonURL = new URL("http://api.brightcove.com/services/library?token="+accountToken+"&page_size=1&command=find_all_videos&output=JSON&get_item_count=true");
HttpURLConnection connection = (HttpURLConnection) jsonURL.openConnection();
connection.setRequestMethod("GET");
connection.connect();
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
String lineRead = "";
while (reader.ready()) {
lineRead = lineRead + reader.readLine();
}
As my browser uses proxy, I added below code to include proxy settings
System.setProperty("http.proxyHost", "my.proxyurl.com");
System.setProperty("http.proxyPort", "80");
Without using proxy settings, it returns java.net.ConnectException: Connection refused: connect and with proxy it gives me java.io.IOException: Server returned HTTP response code: 503
So my question is , why is it giving me a 503(Service Unavailable) error ? From the browser its working fine.
Update 1:
It seems like an issue with the Network. I pinged the domain and it said "Request Timed out". Working via HTTP though. Looks like an issue with the Firewall.

I think, it may due to your internet connection, I have tried your code I didn't get any 503(Service Unavailable). Check out with different connection connection(without proxy) and it should work. Or you can try it with slightly different approach:
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("host", "port));
conn = new URL(jsonURL).openConnection(proxy);
If you have SOCKS type proxy, change Proxy's constructor parameter to Proxy.Type.SOCKS.

Minor correction to Jamas code
String host="myproxy.com";
int port=8080;
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(host, port));