send xhr-polling from other threads

src/main/java/com/github/nkzawa/engineio/client/transports/PollingXHR.java

@@ -6,6 +6,8 @@ import com.github.nkzawa.emitter.Emitter;
 import java.io.*;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.logging.Logger;
 
 public class PollingXHR extends Polling {
@@ -78,6 +80,8 @@ public class PollingXHR extends Polling {
 
     private static class Request extends Emitter {
 
+        private static final ExecutorService xhrService = Executors.newCachedThreadPool();
+
         String method;
         String uri;
         String data;
@@ -106,13 +110,18 @@ public class PollingXHR extends Polling {
             }
 
             logger.info(String.format("sending xhr with url %s | data %s", this.uri, this.data));
-
+            xhrService.submit(new Runnable() {
+                @Override
+                public void run() {
+                    BufferedWriter writer = null;
                     BufferedReader reader = null;
                     try {
-                if (this.data != null) {
-                    byte[] data = this.data.getBytes("UTF-8");
+                        if (self.data != null) {
+                            byte[] data = self.data.getBytes("UTF-8");
                             xhr.setFixedLengthStreamingMode(data.length);
-                    xhr.getOutputStream().write(data);
+                            writer = new BufferedWriter(new OutputStreamWriter(xhr.getOutputStream()));
+                            writer.write(self.data);
+                            writer.flush();
                         }
 
                         String line;
@@ -121,15 +130,20 @@ public class PollingXHR extends Polling {
                         while ((line = reader.readLine()) != null) {
                             data.append(line);
                         }
-                this.onData(data.toString());
+                        self.onData(data.toString());
                     } catch (IOException e) {
-                this.onError(e);
+                        self.onError(e);
                     } finally {
+                        try {
+                            if (writer != null) writer.close();
+                        } catch (IOException e) {}
                         try {
                             if (reader != null) reader.close();
                         } catch (IOException e) {}
                     }
                 }
+            });
+        }
 
         public void onSuccess() {
             this.emit("success");

src/test/java/com/github/nkzawa/engineio/client/SocketTest.java

@@ -73,8 +73,8 @@ public class SocketTest {
     public void stopServer() throws InterruptedException {
         System.out.println("Stopping server ...");
         serverProcess.destroy();
-        serverOutout.cancel(true);
-        serverError.cancel(true);
+        serverOutout.cancel(false);
+        serverError.cancel(false);
         serverService.shutdown();
         serverService.awaitTermination(3000, TimeUnit.MILLISECONDS);
     }