WW-4900 Makes BackgroundProcess transient

core/src/main/java/org/apache/struts2/interceptor/BackgroundProcess.java

@@ -31,10 +31,11 @@ public class BackgroundProcess implements Serializable {
 
     private static final long serialVersionUID = 3884464776311686443L;
 
-    protected Object action;
-    protected ActionInvocation invocation;
+    //WW-4900 transient since 2.5.15
+    transient protected ActionInvocation invocation;
+    transient protected Exception exception;
+
     protected String result;
-    protected Exception exception;
     protected boolean done;
 
     /**
@@ -46,7 +47,6 @@ public class BackgroundProcess implements Serializable {
      */
     public BackgroundProcess(String threadName, final ActionInvocation invocation, int threadPriority) {
         this.invocation = invocation;
-        this.action = invocation.getAction();
         try {
             final Thread t = new Thread(new Runnable() {
                 public void run() {
@@ -96,7 +96,7 @@ protected void afterInvocation() throws Exception {
      * @return  the action.
      */
     public Object getAction() {
-        return action;
+        return invocation.getAction();
     }
 
     /**

core/src/main/java/org/apache/struts2/interceptor/ExecuteAndWaitInterceptor.java

@@ -243,6 +243,12 @@ protected String doIntercept(ActionInvocation actionInvocation) throws Exception
         synchronized (httpSession) {
             BackgroundProcess bp = (BackgroundProcess) session.get(KEY + name);
 
+            //WW-4900 Checks if from a de-serialized session? so background thread missed, let's start a new one.
+            if (bp != null && bp.getInvocation() == null) {
+                session.remove(KEY + name);
+                bp = null;
+            }
+
             if ((!executeAfterValidationPass || secondTime) && bp == null) {
                 bp = getNewBackgroundProcess(name, actionInvocation, threadPriority);
                 session.put(KEY + name, bp);

core/src/test/java/org/apache/struts2/interceptor/BackgroundProcessTest.java

@@ -0,0 +1,65 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.struts2.interceptor;
+
+import com.opensymphony.xwork2.ActionContext;
+import com.opensymphony.xwork2.mock.MockActionInvocation;
+import org.apache.struts2.StrutsInternalTestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+/**
+ * Test case for BackgroundProcessTest.
+ */
+public class BackgroundProcessTest extends StrutsInternalTestCase {
+
+    public void testSerializeDeserialize() throws Exception {
+        MockActionInvocation invocation = new MockActionInvocation();
+        invocation.setResultCode("BackgroundProcessTest.testSerializeDeserialize");
+        invocation.setInvocationContext(ActionContext.getContext());
+
+        BackgroundProcess bp = new BackgroundProcess("BackgroundProcessTest.testSerializeDeserialize", invocation
+                , Thread.MIN_PRIORITY);
+
+        bp.exception = new Exception();
+        bp.done = true;
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        ObjectOutputStream oos = new ObjectOutputStream(baos);
+        oos.writeObject(bp);
+        oos.close();
+        assertTrue("should have serialized data", baos.size() > 0);
+        byte b[] = baos.toByteArray();
+        baos.close();
+
+        ByteArrayInputStream bais = new ByteArrayInputStream(b);
+        ObjectInputStream ois = new ObjectInputStream(bais);
+        BackgroundProcess deserializedBp = (BackgroundProcess) ois.readObject();
+        ois.close();
+        bais.close();
+
+        assertNull("invocation should not be serialized", deserializedBp.invocation);
+        assertNull("exception should not be serialized", deserializedBp.exception);
+        assertEquals(bp.result, deserializedBp.result);
+        assertEquals(bp.done, deserializedBp.done);
+    }
+}

core/src/test/java/org/apache/struts2/interceptor/ExecuteAndWaitInterceptorTest.java

@@ -38,6 +38,10 @@
 import org.apache.struts2.views.jsp.StrutsMockHttpSession;
 
 import javax.servlet.http.HttpSession;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -159,6 +163,41 @@ public void testWaitDelayAndJobAlreadyDone2() throws Exception {
         assertTrue("Job done already after 500 so there should not be such long delay", diff <= 1000);
     }
 
+    public void testFromDeserializedSession() throws Exception {
+        waitInterceptor.setDelay(0);
+        waitInterceptor.setDelaySleepInterval(0);
+
+        ActionProxy proxy = buildProxy("action1");
+        String result = proxy.execute();
+        assertEquals("wait", result);
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        ObjectOutputStream oos = new ObjectOutputStream(baos);
+        oos.writeObject(session);//WW-4900 action1 and invocation are not serializable but we should not fail at this line
+        oos.close();
+        byte b[] = baos.toByteArray();
+        baos.close();
+
+        ByteArrayInputStream bais = new ByteArrayInputStream(b);
+        ObjectInputStream ois = new ObjectInputStream(bais);
+        session = (Map) ois.readObject();
+        context.put(ActionContext.SESSION, session);
+        ois.close();
+        bais.close();
+
+        Thread.sleep(1000);
+
+        ActionProxy proxy2 = buildProxy("action1");
+        String result2 = proxy2.execute();
+        assertEquals("wait", result2);//WW-4900 A new thread should be started when background thread missed
+
+        Thread.sleep(1000);
+
+        ActionProxy proxy3 = buildProxy("action1");
+        String result3 = proxy3.execute();
+        assertEquals("success", result3);
+    }
+
     protected ActionProxy buildProxy(String actionName) throws Exception {
         return actionProxyFactory.createActionProxy("", actionName, null, context);
     }