Show message for missing Atmosphere or version mismatch (#11499)

Change-Id: I05ed55319092248db4a3f2d0975f918c9176a6c6

server/src/com/vaadin/server/Constants.java

@@ -63,6 +63,27 @@ public interface Constants {
             + " Widgetset version: %s\n"
             + "=================================================================";
 
+    static final String REQUIRED_ATMOSPHERE_VERSION = "1.0.12";
+
+    static final String INVALID_ATMOSPHERE_VERSION_WARNING = "\n"
+            + "=================================================================\n"
+            + "With push enabled, Vaadin depends on Atomsphere {0} but\n"
+            + "version {1} was found. This might cause compatibility\n"
+            + "problems.\n"
+            + "=================================================================";
+
+    static final String ATMOSPHERE_MISSING_ERROR = "\n"
+            + "=================================================================\n"
+            + "Atmosphere could not be loaded. When using push with Vaadin, the\n"
+            + "Atmosphere framework must be present on the classpath.\n"
+            + "If using a dependency management system, please add a dependency\n"
+            + "to vaadin-push.\n"
+            + "If managing dependencies manually, please make sure Atmosphere\n"
+            + REQUIRED_ATMOSPHERE_VERSION
+            + " is included on the classpath.\n"
+            + "Push will be disabled.\n"
+            + "=================================================================";
+
     static final String URL_PARAMETER_THEME = "theme";
 
     static final String SERVLET_PARAMETER_PRODUCTION_MODE = "productionMode";

server/src/com/vaadin/server/DefaultDeploymentConfiguration.java

@@ -17,8 +17,11 @@
 package com.vaadin.server;
 
 import java.util.Properties;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import org.atmosphere.util.Version;
+
 import com.vaadin.shared.communication.PushMode;
 
 /**
@@ -265,6 +268,28 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
             getLogger().warning(Constants.WARNING_PUSH_MODE_NOT_RECOGNIZED);
             pushMode = PushMode.DISABLED;
         }
+
+        if (pushMode != PushMode.DISABLED && !checkAtomsphereVersion()) {
+            pushMode = PushMode.DISABLED;
+        }
+    }
+
+    private boolean checkAtomsphereVersion() {
+        try {
+            String rawVersion = Version.getRawVersion();
+            if (!Constants.REQUIRED_ATMOSPHERE_VERSION.equals(rawVersion)) {
+                getLogger().log(
+                        Level.WARNING,
+                        Constants.INVALID_ATMOSPHERE_VERSION_WARNING,
+                        new Object[] { Constants.REQUIRED_ATMOSPHERE_VERSION,
+                                rawVersion });
+            }
+            return true;
+        } catch (NoClassDefFoundError e) {
+            getLogger()
+                    .log(Level.SEVERE, Constants.ATMOSPHERE_MISSING_ERROR, e);
+            return false;
+        }
     }
 
     private Logger getLogger() {

server/tests/src/com/vaadin/tests/server/TestAtmosphereVersion.java

@@ -0,0 +1,18 @@
+package com.vaadin.tests.server;
+
+import junit.framework.TestCase;
+
+import org.atmosphere.util.Version;
+
+import com.vaadin.server.Constants;
+
+public class TestAtmosphereVersion extends TestCase {
+    /**
+     * Test that the atmosphere version constant matches the version on our
+     * classpath
+     */
+    public void testAtmosphereVersion() {
+        assertEquals(Constants.REQUIRED_ATMOSPHERE_VERSION,
+                Version.getRawVersion());
+    }
+}