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HTTPClient never leaves socketRead() when executing GET on stream - workaround?

I am using Apache HttpClient (from Apache HTTP Components 4.3) in order to execute a GET against a ShoutCast stream:
CloseableHttpClient client = HttpClients.createDefault();
HttpGet request = new HttpGet("http://relay3.181.fm:8062/");
CloseableHttpResponse response = client.execute(request);
The call to client.execute() never returns, and according to the debugger it is a nested invocation to java.net.SocketInputStream#socketRead0() which is the last node in the call stack. From profiling the code, my only conclusion (based on a steadily rising number of char[] allocations) is that it simply "latches on" to the stream and keeps pulling bytes from the socket indefinitely.
What I would like is for the client to simply work normally and give me a HTTPResponse which I can use to pull what I want from the stream. As a matter of fact, I have been able to do so with other ShoutCast streams, but not this one.
Is there any way to work around this? Could I for example tell the client to break off after a certain number of bytes?

That site is very particular. If you don't specify a supported User-Agent (like Mozilla), the server keep streaming bytes. I don't know what these bytes are meant to represent, audio perhaps.
If you print out the bytes that you receive, you will see
ICY 200 OK
icy-notice1:<BR>This stream requires Winamp<BR>
icy-notice2:SHOUTcast Distributed Network Audio Server/Linux v1.9.8<BR>
icy-name:181.FM - The Beatles Channel
icy-genre:Oldies
icy-url:http://www.181.fm
content-type:audio/mpeg
icy-pub:1
icy-br:128
which indicates that the response is not a valid HTTP response. It is an ICY response from the ICY protocol.
Now the default HttpClient you are using uses a DefaultHttpResponseParser which is a
Lenient HTTP response parser implementation that can skip malformed
data until a valid HTTP response message head is encountered.
In other words, it keeps reading the bytes the server is sending until it finds a valid HTTP response header, which will never happen, thus the infinite read.
I don't think you will be able to accomplish what you want with the Http Components library. Either look for an ICY client implementation in Java or spin your own.

How it comes that URL.openConnection() allows me to read header?

I recently was experimenting with java networking and I found a bit odd thing, suppose you have
URL url = new URL("http://www.google.com");
URLConnection con = url.openConnection();
then i can call methods, like con.getContentLength() and so on and they will give me correct values, even despite I didn't envoke con.connect(). How can that be? I mean, where from/how does URLConnection gets those headers, I didn't invoke con.connect() yet, so no requests were sent and so no headers should be available at that moment.

The actual TCP connect happens implicitly when you call any method that requires the response, such as getContentLength(), getInputStream(), getResponseCode(). It doesn't happen at openConnection(). The request is sent at that point.
Unless you are using one of the streaming modes and you're doing a PUT or POST with request content, in which case the connection is opened when you start writing the request.

Apache HTTPClient Streaming HTTP POST Request?

I'm trying to build a "full-duplex" HTTP streaming request using Apache HTTPClient.
In my first attempt, I tried using the following request code:
URL url=new URL(/* code goes here */);
HttpPost request=new HttpPost(url.toString());
request.addHeader("Connection", "close");
PipedOutputStream requestOutput=new PipedOutputStream();
PipedInputStream requestInput=new PipedInputStream(requestOutput, DEFAULT_PIPE_SIZE);
ContentType requestContentType=getContentType();
InputStreamEntity requestEntity=new InputStreamEntity(requestInput, -1, requestContentType);
request.setEntity(requestEntity);
HttpEntity responseEntity=null;
HttpResponse response=getHttpClient().execute(request); // <-- Hanging here
try {
if(response.getStatusLine().getStatusCode() != 200)
throw new IOException("Unexpected status code: "+response.getStatusLine().getStatusCode());
responseEntity = response.getEntity();
}
finally {
if(responseEntity == null)
request.abort();
}
InputStream responseInput=responseEntity.getContent();
ContentType responseContentType;
if(responseEntity.getContentType() != null)
responseContentType = ContentType.parse(responseEntity.getContentType().getValue());
else
responseContentType = DEFAULT_CONTENT_TYPE;
Reader responseStream=decode(responseInput, responseContentType);
Writer requestStream=encode(requestOutput, getContentType());
The request hangs at the line indicated above. It seems that the code is trying to send the entire request before it gets the response. In retrospect, this makes sense. However, it's not what I was hoping for. :)
Instead, I was hoping to send the request headers with Transfer-Encoding: chunked, receive a response header of HTTP/1.1 200 OK with a Transfer-Encoding: chunked header of its own, and then I'd have a full-duplex streaming HTTP connection to work with.
Happily, my HTTPClient has another NIO-based asynchronous client with good usage examples (like this one). My questions are:
Is my interpretation of the synchronous HTTPClient behavior correct? Or is there something I can do to continue using the (simpler) synchronous HTTPClient in the manner I described?
Does the NIO-based client wait to send the whole request before seeking a response? Or will I be able to send the request incrementally and receive the response incrementally at the same time?
If HTTPClient will not support this modality, is there another HTTP client library that will? Or should I be planning to write a (minimal) HTTP client to support this modality?

Here is my view on skim reading the code:
I cannot completely agree with the fact that a non-200 response means failure. All 2XX responses are mostly valid. Check wiki for more details
For any TCP request, I would recommend to receive the entire response to confirm that it is valid. I say this because, a partial response may mostly be treated as bad response as most of the client implementations cannot make use of it. (Imagine a case where server is responding with 2MB of data and it goes down during this time)

A separate thread must be writing to the OutputStream for your code to
work.
The code above provides the HTTPClient with a PipedInputStream.
PipedInputStream makes bytes available as they are written to the corresponding OutputStream.
The code above does not write to the OutputStream (which must be done by a separate thread.
Therefore the code is hanging exactly where your comment is.
Under the hood, the Apache client says "inputStream.read()" which in the case of piped streams requires that outputStream.write(bytes) was called previously (by a separate thread).
Since you aren't pumping bytes into the associated OutputStream from a separate thread the InputStream just sits and waits for the OutputStream to be written to by "some other thread."
From the JavaDocs:
A piped input stream should be connected to a piped output stream;
the piped input stream then provides whatever data bytes are written
to the piped output stream.
Typically, data is read from a PipedInputStream object by one thread
and data is written to the corresponding PipedOutputStream by some
other thread.
Attempting to use both objects from a single thread is not
recommended, as it may deadlock the thread.
The piped input stream contains a buffer, decoupling read operations
from write operations, within limits. A pipe is said to be "broken"
if a thread that was providing data bytes to the connected piped
output stream is no longer alive.
Note: Seems to me, since piped streams and concurrency were not mentioned in your problem statement, that it's not necessary. Try wrapping a ByteArrayInputStream() with the Entity object instead first for a sanity check... that should help you narrow down the issue.
Update
Incidentally, I wrote an inversion of Apache's HTTP Client API [PipedApacheClientOutputStream] which provides an OutputStream interface for HTTP POST using Apache Commons HTTP Client 4.3.4. This may be close to what you are looking for...
Calling-code looks like this:
// Calling-code manages thread-pool
ExecutorService es = Executors.newCachedThreadPool(
new ThreadFactoryBuilder()
.setNameFormat("apache-client-executor-thread-%d")
.build());
// Build configuration
PipedApacheClientOutputStreamConfig config = new
PipedApacheClientOutputStreamConfig();
config.setUrl("http://localhost:3000");
config.setPipeBufferSizeBytes(1024);
config.setThreadPool(es);
config.setHttpClient(HttpClientBuilder.create().build());
// Instantiate OutputStream
PipedApacheClientOutputStream os = new
PipedApacheClientOutputStream(config);
// Write to OutputStream
os.write(...);
try {
os.close();
} catch (IOException e) {
logger.error(e.getLocalizedMessage(), e);
}
// Do stuff with HTTP response
...
// Close the HTTP response
os.getResponse().close();
// Finally, shut down thread pool
// This must occur after retrieving response (after is) if interested
// in POST result
es.shutdown();
Note - In practice the same client, executor service, and config will likely be reused throughout the life of the application, so the outer prep and close code in the above example will likely live in bootstrap/init and finalization code rather than directly inline with the OutputStream instantiation.

How to use HttpClient to download continous data stream?

I'm currently using HttpURLConnection to stream live content such as a radio broadcast. However it seems that using HttpClient is a better option since it's well supported by Android and it's a better implementation. Also, there seems to be a logic for automatic reconnection from a lost connection.
My problem is that I can't get this to work. It's always hanging when calling httpclient.execute(...).
What am I doing wrong?
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet("http://208.76.243.123:7100");
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();

Run it in debugger and when it hangs, call break. Then find the thread that is executing your code and see in stack trace where exactly it blocked. You will see if it blocked on IO or something else is happening. With that data it will be easier to identify the problem.

Are you sure your server understands the HTTP protocol? (I assume yes, it sounds like you had a different client working). It is possible the execute method is blocking because it has not seen a valid Response header yet.
You probably want entity.getContent() which will return a handle to a stream. See this question.

HTTP 1.1 Persistent Connections using Sockets in Java

Let's say I have a java program that makes an HTTP request on a server using HTTP 1.1 and doesn't close the connection. I make one request, and read all data returned from the input stream I have bound to the socket. However, upon making a second request, I get no response from the server (or there's a problem with the stream - it doesn't provide any more input). If I make the requests in order (Request, request, read) it works fine, but (request, read, request, read) doesn't.
Could someone shed some insight onto why this might be happening? (Code snippets follow). No matter what I do, the second read loop's isr_reader.read() only ever returns -1.
try{
connection = new Socket("SomeServer", port);
con_out = connection.getOutputStream();
con_in = connection.getInputStream();
PrintWriter out_writer = new PrintWriter(con_out, false);
out_writer.print("GET http://somesite HTTP/1.1\r\n");
out_writer.print("Host: thehost\r\n");
//out_writer.print("Content-Length: 0\r\n");
out_writer.print("\r\n");
out_writer.flush();
// If we were not interpreting this data as a character stream, we might need to adjust byte ordering here.
InputStreamReader isr_reader = new InputStreamReader(con_in);
char[] streamBuf = new char[8192];
int amountRead;
StringBuilder receivedData = new StringBuilder();
while((amountRead = isr_reader.read(streamBuf)) > 0){
receivedData.append(streamBuf, 0, amountRead);
}
// Response is processed here.
if(connection != null && !connection.isClosed()){
//System.out.println("Connection Still Open...");
out_writer.print("GET http://someSite2\r\n");
out_writer.print("Host: somehost\r\n");
out_writer.print("Connection: close\r\n");
out_writer.print("\r\n");
out_writer.flush();
streamBuf = new char[8192];
amountRead = 0;
receivedData.setLength(0);
while((amountRead = isr_reader.read(streamBuf)) > 0 || amountRead < 1){
if (amountRead > 0)
receivedData.append(streamBuf, 0, amountRead);
}
}
// Process response here
}
Responses to questions:
Yes, I'm receiving chunked responses from the server.
I'm using raw sockets because of an outside restriction.
Apologies for the mess of code - I was rewriting it from memory and seem to have introduced a few bugs.
So the consensus is I have to either do (request, request, read) and let the server close the stream once I hit the end, or, if I do (request, read, request, read) stop before I hit the end of the stream so that the stream isn't closed.

According to your code, the only time you'll even reach the statements dealing with sending the second request is when the server closes the output stream (your input stream) after receiving/responding to the first request.
The reason for that is that your code that is supposed to read only the first response
while((amountRead = isr_reader.read(streamBuf)) > 0) {
receivedData.append(streamBuf, 0, amountRead);
}
will block until the server closes the output stream (i.e., when read returns -1) or until the read timeout on the socket elapses. In the case of the read timeout, an exception will be thrown and you won't even get to sending the second request.
The problem with HTTP responses is that they don't tell you how many bytes to read from the stream until the end of the response. This is not a big deal for HTTP 1.0 responses, because the server simply closes the connection after the response thus enabling you to obtain the response (status line + headers + body) by simply reading everything until the end of the stream.
With HTTP 1.1 persistent connections you can no longer simply read everything until the end of the stream. You first need to read the status line and the headers, line by line, and then, based on the status code and the headers (such as Content-Length) decide how many bytes to read to obtain the response body (if it's present at all). If you do the above properly, your read operations will complete before the connection is closed or a timeout happens, and you will have read exactly the response the server sent. This will enable you to send the next request and then read the second response in exactly the same manner as the first one.
P.S. Request, request, read might be "working" in the sense that your server supports request pipelining and thus, receives and processes both request, and you, as a result, read both responses into one buffer as your "first" response.
P.P.S Make sure your PrintWriter is using the US-ASCII encoding. Otherwise, depending on your system encoding, the request line and headers of your HTTP requests might be malformed (wrong encoding).

Writing a simple http/1.1 client respecting the RFC is not such a difficult task.
To solve the problem of the blocking i/o access where reading a socket in java, you must use java.nio classes.
SocketChannels give the possibility to perform a non-blocking i/o access.
This is necessary to send HTTP request on a persistent connection.
Furthermore, nio classes will give better performances.
My stress test give to following results :
HTTP/1.0 (java.io) -> HTTP/1.0 (java.nio) = +20% faster
HTTP/1.0 (java.io) -> HTTP/1.1 (java.nio with persistent connection) = +110% faster

Make sure you have a Connection: keep-alive in your request. This may be a moot point though.
What kind of response is the server returning? Are you using chunked transfer? If the server doesn't know the size of the response body, it can't provide a Content-Length header and has to close the connection at the end of the response body to indicate to the client that the content has ended. In this case, the keep-alive won't work. If you're generating content on-the-fly with PHP, JSP etc., you can enable output buffering, check the size of the accumulated body, push the Content-Length header and flush the output buffer.

Is there a particular reason you're using raw sockets and not Java's URL Connection or Commons HTTPClient?
HTTP isn't easy to get right. I know Commons HTTP Client can re-use connections like you're trying to do.
If there isn't a specific reason for you using Sockets this is what I would recommend :)

Writing your own correct client HTTP/1.1 implementation is nontrivial; historically most people who I've seen attempt it have got it wrong. Their implementation usually ignores the spec and just does what appears to work with one particular test server - in particular, they usually ignore the requirement to be able to handle chunked responses.
Writing your own HTTP client is probably a bad idea, unless you have some VERY strange requirements.