java - How to read http request properly? -

how read http request using inputstream? used read this:

inputstream in = address.openstream(); bufferedreader reader = new bufferedreader(new inputstreamreader(in)); stringbuilder result = new stringbuilder(); string line; while((line = reader.readline()) != null) {     result.append(line); } system.out.println(result.tostring());  

but reader.readline() blocked, because there no guarantee null line reached. of course can read content-length header , read request in loop:

for (int = 0; < contentlength; i++) {                 int = br.read();                 body.append((char) a);     } 

but if content-length set big(i guess set manually purpose), br.read() blocked. try read bytes directly inputstream this:

byte[] bytes = getbytes(is);  public static byte[] getbytes(inputstream is) throws ioexception {              int len;             int size = 1024;             byte[] buf;              if (is instanceof bytearrayinputstream) {               size = is.available();               buf = new byte[size];               len = is.read(buf, 0, size);             } else {               bytearrayoutputstream bos = new bytearrayoutputstream();               buf = new byte[size];               while ((len = is.read(buf, 0, size)) != -1)                 bos.write(buf, 0, len);               buf = bos.tobytearray();             }             return buf;           } 

but waits forever. do?

if implementing http server should detect end of request according http specification. wiki - https://en.wikipedia.org/wiki/hypertext_transfer_protocol

first of all, should read request line, single line. read request headers. read them until have empty line (i.e. 2 line endings - <cr><lf>).

after have status line , headers should decide need read body or no because not requests might have body - summary table

then, if need body, should parse headers (which got) , content-length. if - read many bytes stream specified. when content-length missing length determined in other ways. chunked transfer encoding uses chunk size of 0 mark end of content. identity encoding without content-length reads content until socket closed.