AtmosphereResponseDetectDeadConnection.patch

From cc81debbf5ca6b0979dbb2104b2ac60f6492c86c Mon Sep 17 00:00:00 2001
From: Artur Signell <artur@vaadin.com>
Date: Wed, 29 Jul 2015 18:16:22 +0300
Subject: [PATCH] Use two-step write so Tomcat correctly reports a dead
 connection

Change-Id: Ief2a1111926eefcb131d082b453081c705103e86
---
 .../org/atmosphere/cpr/AtmosphereResponse.java     | 26 ++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/modules/cpr/src/main/java/org/atmosphere/cpr/AtmosphereResponse.java b/modules/cpr/src/main/java/org/atmosphere/cpr/AtmosphereResponse.java
index c162eca..352ae51 100644
--- a/modules/cpr/src/main/java/org/atmosphere/cpr/AtmosphereResponse.java
+++ b/modules/cpr/src/main/java/org/atmosphere/cpr/AtmosphereResponse.java
@@ -891,7 +891,7 @@ public class AtmosphereResponse extends HttpServletResponseWrapper {
             if (isUsingStream()) {
                 try {
                     OutputStream o = writeUsingOriginalResponse ? _r().getOutputStream() : getOutputStream();
-                    o.write(data.getBytes(getCharacterEncoding()));
+                    twoStepWrite(o, data.getBytes(getCharacterEncoding()));
                 } catch (java.lang.IllegalStateException ex) {
                     logger.trace("", ex);
                 }
@@ -956,7 +956,7 @@ public class AtmosphereResponse extends HttpServletResponseWrapper {
             if (isUsingStream()) {
                 try {
                     OutputStream o = writeUsingOriginalResponse ? _r().getOutputStream() : getOutputStream();
-                    o.write(data);
+                    twoStepWrite(o, data);
                 } catch (java.lang.IllegalStateException ex) {
                 }
             } else {
@@ -1086,6 +1086,28 @@ public class AtmosphereResponse extends HttpServletResponseWrapper {
         return new Builder().response(response).build();
     }
 
+	/**
+	 * Writes the given data to the given outputstream in two steps with extra
+	 * flushes to make servers notice if the connection has been closed. This
+	 * enables caching the message instead of losing it, if the client is in the
+	 * progress of reconnecting
+	 * 
+	 * @param o the stream to write to
+	 * @param data the data to write
+	 * @throws IOException if an exception occurs during writing
+	 */
+	public void twoStepWrite(OutputStream o, byte[] data) throws IOException {
+		if (data.length > 1) {
+			o.write(data, 0, 1);
+			o.flush();
+			o.write(data, 1, data.length - 1);
+			o.flush();
+		} else {
+			o.write(data);
+		}
+
+	}
+
     @Override
     public String toString() {
         return "AtmosphereResponse{" +
-- 
2.5.0