I am trying to create a proxy server.
I want to read the websites byte by byte so that I can display images and all other stuff. I tried readLine but I can't display images. Do you have any suggestions how I can change my code and send all data with DataOutputStream object to browser ?
try{
Socket s = new Socket(InetAddress.getByName(req.hostname), 80);
String file = parcala(req.url);
DataOutputStream out = new DataOutputStream(clientSocket.getOutputStream());
BufferedReader dis = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter socketOut = new PrintWriter(s.getOutputStream());
socketOut.print("GET "+ req.url + "\n\n");
//socketOut.print("Host: "+req.hostname);
socketOut.flush();
String line;
while ((line = dis.readLine()) != null){
System.out.println(line);
}
}
catch (Exception e){}
}
Edited Part
This is what I should have to do. I can block banned web sites but can't allow other web sites in my program.
In the filter program, you will open a TCP socket at the specified port and wait for connections. If a
request comes (i.e. the client types a URL to access a web site), the application will process it to
decide whether access is allowed or not and then, using the same socket, it will send the reply back
to the client. After the client opened her connection to WebPolice (and her request has been checked
and is allowed), the real web page needs to be shown to the client. Therefore, since the user already gave her request, now it is WebPolice’s turn to forward the request so that the user can get the web page. Thus, WebPolice acts as a client and requests the web page. This means you need to open a connection to the web server (without closing the connection to the user), forward the request over this connection, get the reply and forward it back to the client. You will use threads to handle multiple connections (at the same time and/or at different times).
I don't know what exactly you're trying to do, but crafting an HTTP request and reading its response incorporates somewhat more than you have done here. Readline won't work on binary data anyway.
You can take a look at the URLConnection class (stolen here):
URL oracle = new URL("http://www.oracle.com/");
URLConnection yc = oracle.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
Then you can read textual or binary data from the in object.
Read line will treat the line read as a String, so unless you want to mess around with conversions over to bytes, I wouldn't recommend that.
I would just read bytes until you can't read anymore, then write them out to a file, this should allow you to grab the images, keeping file headers intact which can be important when dealing with files other than text.
Hope this helps.
Instead of using BufferedReader you can try to use InputStream.
It has several methods for reading bytes.
http://docs.oracle.com/javase/6/docs/api/java/io/InputStream.html
Related
I want to stream a radio with Java, my approach is to download the playlist file (.pls), then extract one of the urls given in that same file and finally, stream it with java. However, it seems I cannot find a way to do it.. I tried with JMF, but I get java.io.IOException: Invalid Http response everytime I run the code.
Here is what I tried:
Player player = Manager.createPlayer(new URL("http://50.7.98.106:8398"));
player.start();
The .pls file:
[playlist]
NumberOfEntries=1
File1=http://50.7.98.106:8398/
In the piece of code above I'm setting the URL by hand, just for testing, but I've sucessfuly done the .pls downloading code and it's working, and from this I make another question, is it a better approach to just simply play the .pls file locally? Can it be done?
You are connecting to an Icecast server, not a web server. That address/port is not sending back HTTP responses, it's sending back Icecast responses.
The HTTP specification states that the response line must start with the HTTP version of the response. Icecast responses don't do that, so they are not valid HTTP responses.
I don't know anything about implementing an Icecast client, but I suspect such clients interpret an http: URL in a .pls file as being just a host and port specification, rather than a true HTTP URL.
You can't use the URL class to download your stream, because it (rightly) rejects invalid HTTP responses, so you'll need to read the data yourself. Fortunately, that part is fairly easy:
Socket connection = new Socket("50.7.98.106", 8398);
String request = "GET / HTTP/1.1\n\n";
OutputStream out = connection.getOutputStream();
out.write(request.getBytes(StandardCharsets.US_ASCII));
out.flush();
InputStream response = connection.getInputStream();
// Skip headers until we read a blank line.
int lineLength;
do {
lineLength = 0;
for (int b = response.read();
b >= 0 && b != '\n';
b = response.read()) {
lineLength++;
}
} while (lineLength > 0);
// rest of stream is audio data.
// ...
You still will need to find something to play the audio. Java Sound can't play MP3s (without a plugin). JMF and JavaFX require a URL, not just an InputStream.
I see a lot of recommendations on Stack Overflow for JLayer, whose Player class accepts an InputStream. Using that, the rest of the code is:
Player player = new Player(response);
player.play();
I want to read the second line of the text at this URL: "http://vuln2014.picoctf.com:51818/" (this is a capture-the-flag competition but only asking for flags or direction to flags breaks the competition rules). I am attempting to open an input stream from the URL but I get an Invalid HTTP Response exception. Any help is appreciated, and I recognize that my error is likely quite foolish.
Code:
URL url = new URL("http://vuln2014.picoctf.com:51818");
URLConnection con = url.openConnection();
InputStream is = con.getInputStream()
The error occurs at the third line.
java.io.IOException: Invalid Http response at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1342) at name.main(name.java:41)
curl happily gets the text from the page, and it is perfectly accessible from a web browser.
When you do this:
URL url = new URL("http://vuln2014.picoctf.com:51818");
URLConnection con = url.openConnection();
You are entering into a contract that says that this URL uses the http protocol. When you call openConnection it expects to get http responses because you used http:// in the URL as the protocol. The Java Documentation says:
If for the URL's protocol (such as HTTP or JAR), there exists a public, specialized URLConnection subclass belonging to one of the following packages or one of their subpackages: java.lang, java.io, java.util, java.net, the connection returned will be of that subclass. For example, for HTTP an HttpURLConnection will be returned, and for JAR a JarURLConnection will be returned.
The server you are connecting to just returns a couple lines of data. I retrieved them with the command nc vuln2014.picoctf.com 51818. There is no http response code like HTTP/1.1 200 OK:
Welcome to the Daedalus Corp Spies RSA Key Generation Service. The public modulus you should use to send your updates is below. Remember to use exponent 65537.
b4ab920c4772c5247e7d89ec7570af7295f92e3b584fc1a1a5624d19ca07cd72ab4ab9c8ec58a63c09f382aa319fa5a714a46ffafcb6529026bbc058fc49fb1c29ae9f414db4aa609a5cab6ff5c7b4c4cfc7c18844f048e3899934999510b2fe25fcf8c572514dd2e14c6e19c4668d9ad82fe647cf9e700dcf6dc23496be30bb
In this case I would use java.net.Socket to establish a connection and then read the lines. This is a simplistic approach that assumes there are 2 lines of data:
Socket theSocket;
try {
theSocket = new Socket("vuln2014.picoctf.com", 51818);
BufferedReader inFile = new BufferedReader(new InputStreamReader(theSocket.getInputStream()));
String strGreet = inFile.readLine();
String strData = inFile.readLine();
} catch (IOException e) {
e.printStackTrace();
}
As for why curl and browsers may render it properly? They are likely more lenient about the data they read and will just dump what is read from the port even if it doesn't conform to the specified protocol (like http)
I have a Java application which opens an existing company's website using the Socket class:
Socket sockSite;
InputStream inFile = null;
BufferedWriter out = null;
try
{
sockSite = new Socket( presetSite, 80 );
inFile = sockSite.getInputStream();
out = new BufferedWriter( new OutputStreamWriter(sockSite.getOutputStream()) );
}
catch ( IOException e )
{
...
}
out.write( "GET " + presetPath + " HTTP/1.1\r\n\r\n" );
out.flush();
I would read the website with the stream inFile and life is good.
Recently this started to fail. I was getting an HTTP 301 "site has moved" error but no moved-to link. The site still exists and responds using the same original HTTP reference and any web browser. But the above code comes back with the HTTP 301.
I changed the code to this:
URL url;
InputStream inFile = null;
try
{
url = new URL( presetSite + presetPath );
inFile = url.openStream();
}
catch ( IOException e )
{
...
}
And read the site with the original code from inFile stream and it now works again.
This difference doesn't just occur in Java but it also occurs if I use Perl (using IO::Socket::INET approach opening the website port 80, then issuing a GET fails, but using LWP::Simple method get just works). In other words, I get a failure if I open the web page first with port 80, then do a GET, but it works fine if I use a class which does it "all at once" (that just says, "get me web page with such-and-such an HTTP address").
I thought I'd try the different approaches on http://www.microsoft.com and got an interesting result. In the case of opening port 80, followed by issuing the GET /..., I received an HTTP 200 response with a page that said, "Your current user agent
In one case, I tried the "port 80" open followed by GET / on www.microsoft.com and I received an HTTP 200 response page that said, "Your current user agent appears to be from an automated process...". But if I use the second method (URL class in Java, or LWP in Perl) I simply get their web page.
So my question is: how does the URL class (in Java) or the LWP module (in Perl) do its thing under the hood that makes it different from opening the website on port 80 and issuing a GET?
Most servers require the Host: header, to allow virtual hosting (multiple domains on one IP)
If you use a packet capturing software to see what's being sent when URL is used, you'll realize that there's a lot more than just "GET /" being sent. All sorts of additional header information are included. If a server gets just a simple "GET /", it's easy to deduct that it can't be a very sophisticated client on the other end.
Also, HTTP 1.0 is "outdated", the current version is 1.1.
Java URL implementation delegates to HttpURLConnection if it starts with "http:"
I have a php page in my server that accepts a couple of POST requests and process them. Lets say it's a simple page and the output is simply an echoed statement. With the URLConnection I established from a Java program to send the POST request, I tried to get the input using the input stream got through connection.getInputStream(). But All I get is the source of the page(the whole php script) and not the output it produces. We shall avoid socket connections here. Can this be done with Url connection or HttpRequest? How?
class htttp{
public static void main(String a[]) throws IOException{
URL url=new URL("http://localhost/test.php");
URLConnection conn = url.openConnection();
//((HttpURLConnection) conn).setRequestMethod("POST");
conn.setDoOutput(true);
conn.setDoInput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write("Hello");
wr.flush();
wr.close();
InputStream ins = conn.getInputStream();
InputStreamReader isr = new InputStreamReader(ins);
BufferedReader in = new BufferedReader(isr);
String inputLine;
String result = "";
while( (inputLine = in.readLine()) != null )
result += inputLine;
System.out.print(result);
}
}
I get the whole source of the webpage test.php in result. But I want only the output of the php script.
The reason you get the PHP source itself, rather than the output it should be rendering, is that your local HTTP server - receiving your request targeted at http://localhost/test.php - decided to serve back the PHP source, rather than forward the HTTP request to a PHP processor to render the output.
Why this happens? that has to do with your HTTP server's configuration; there might be a few reasons for that. For starters, you should validate your HTTP server's configuration.
Which HTTP server are you using on your machine?
What happens when you browse http://localhost/test.php through your browser?
The problem here is not the Java code - the problem lies with the web server. You need to investigate why your webserver is not executing your PHP script but sending it back raw. You can begin by testing using a simple PHP scipt which returns a fixed result and is accessed using a GET request (from a web browser). Once that is working you can test using the one that responds to POST requests.
I am sending a request on a server URL but I am getting File not found exception but when I browse this file through a web browser it seems fine.
URL url = new URL(serverUrl);
connection = getSecureConnection(url);
// Connect to server
connection.connect();
// Send parameters to server
writer = new BufferedWriter(new OutputStreamWriter(connection.getOutputStream(), "UTF-8"));
writer.write(parseParameters(CoreConstants.ACTION_PREFIX + actionName, parameters));
writer.flush();
// Read server's response
reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
when I try to getInputStream then it throws error file not found.
It is an .aspx Controller page.
If the request works fine in a browser but not in code, and you've verified that the URL is the same, then the problem probably has something to do with how you are sending your parameters to the server. Specifically, this part:
writer.write(parseParameters(CoreConstants.ACTION_PREFIX + actionName, parameters));
Perhaps there is a bug in the parseParameters() function?
But more generally, I would recommend using something a bit higher-level than a raw URLConnection. HtmlUnit and HttpClient are both fine choices, particularly since it seems like your request is a fairly simple one. I've used both to perform similar client/server interaction in a number of apps. I suggest revising your code to use one of these libraries, and then see if it still produces the error.
Ok finally I have found that the problem was at IIS side it has been resolved in .Net 4.0. for previous version go to your web.config and specify validateRequest==false