Java string comparison with equals() not working as expected with UDP -


i trying send message on udp , comparing string literal, not seem work.

here udp server code

import java.net.datagrampacket; import java.net.datagramsocket; import java.net.inetaddress;  public class controller {      public static void main(string args[]) {           //create udp server         try {             datagramsocket socket = new datagramsocket(5002);             byte[] buffer = new byte[1024];             datagrampacket packet = new datagrampacket(buffer, buffer.length);              //wait done message             socket.receive(packet);             string msg = new string (packet.getdata());             if(msg.equals("done"))             {                 system.out.println("done received");             }             else {                 system.out.println("done not received");             }          } catch (exception e) {             e.printstacktrace();         }     } }

and here udp client code

import java.net.datagrampacket; import java.net.datagramsocket; import java.net.inetaddress;  public class slave {      public static void main(string args[]) {         //create udp client         try {             datagramsocket socket = new datagramsocket();             byte[] buffer;              //send done message             buffer = "done".getbytes();             datagrampacket packet = new datagrampacket(buffer, buffer.length, inetaddress.getlocalhost(), 5002);             socket.send(packet);          } catch (exception e) {             e.printstacktrace();         }      } }

the output "done not received", though done message sent. wrong code?

the problem is, declaring buffer 1024 bytes, converting string. string not equal "done", "too long". have obtain actual length of sent data. in controller:

public class controller {      public static void main(string args[]) {           //create udp server         try {             datagramsocket socket = new datagramsocket(5002);             byte[] buffer = new byte[1024];             datagrampacket packet = new datagrampacket(buffer, buffer.length);              //wait done message             socket.receive(packet);              //get actual data length , copy             byte[] data = new byte[packet.getlength()];             system.arraycopy(packet.getdata(), packet.getoffset(), data, 0, packet.getlength());              //create string actual data             string msg = new string (data);             if(msg.equals("done"))             {                 system.out.println("done received");             }             else {                 system.out.println("done not received");             }          } catch (exception e) {             e.printstacktrace();         }     } }

Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj
Read more

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

i'm doing micro-optimization on performance critical part of code , came across sequence of instructions (in at&t syntax): add %rax, %rbx mov %rdx, %rax mov %rbx, %rdx i thought had use case xchg allow me shave instruction , write: add %rbx, %rax xchg %rax, %rdx however, dimay found agner fog's instruction tables , xchg 3 micro-op instruction 2 cycle latency on sandy bridge, ivy bridge, broadwell, haswell , skylake. 3 whole micro-ops , 2 cycles of latency! 3 micro-ops throws off 4-1-1-1 cadence , 2 cycle latency makes worse original in best case since last 2 instructions in original might execute in parallel. now... cpu might breaking instruction micro-ops equivalent to: mov %rax, %tmp mov %rdx, %rax mov %tmp, %rdx where tmp anonymous internal register , suppose last 2 micro-ops run in parallel latency 2 cycles. given register renaming occurs on these micro-architectures, though, doesn't make sense me done way. why wouldn't register renamer
Read more

jquery - Responsive Navbar with Sub Navbar -

good day, forgive me nav vocabulary not best. if question confusing apologize. i'm working on navigation bar needs centered on page @ 768px , above. items in nav open (or perhaps toggle) subnav lives directly below. these nav should appear centered on page. i have been able work through responsive portion of nav bar, having main items align vertically , sub nav menu of each item roll out below, , gave them indent separation. working well. however, issue not responsive side, behavior @ width greater 768px. happens toggling menu's sub navigation pushes other main items down page below sub nav. here's code: $(document).ready(function () { //stick in fixed 100% height behind navbar don't wrap $('#slide-nav.navbar-inverse').after($('<div class="inverse" id="navbar-height-col"></div>')); $('#slide-nav.navbar-default').after($('<div id="navbar-height-col"></d
Read more