* Implement app.invokeAsync() using public FutureResult interface.

src/helma/framework/FutureResult.java

@@ -0,0 +1,59 @@
+/*
+ *  Copyright 2006 Hannes Wallnoefer <hannes@helma.at>
+ *
+ *  Licensed 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 helma.framework;
+
+/**
+ * A handle for an asynchronous request execution. This allows to wait for
+ * request termination, get the result or the exception of the execution.
+ */
+public interface FutureResult {
+    /**
+     * Get the result of the execution. If the execution is still active,
+     * or if the invocation threw an exception, this method immediately returns null.
+     * @return the result, or null
+     */
+    Object getResult();
+
+    /**
+     * Get the exception of the execution, if one was thrown. If the execution
+     * is still active, or if no exception was thrown, this method immediately returns null.
+     * @return the exception, or null
+     */
+    Exception getException();
+
+    /**
+     * Returns true if the execution is still active, and false if not.
+     * @return true if the execution is still active
+     */
+    boolean getRunning();
+
+    /**
+     * Wait for execution to terminat, returning the execution result, if one is available.
+     * @return the execution result, or null
+     * @throws InterruptedException if we were interrupted by some other thread
+     */
+    Object waitForResult() throws InterruptedException;
+
+    /**
+     * Wait for a specific ammount of thime for the execution to terminate, returning
+     * the execution result, if one is available.
+     * @param timeout the number of milliseconds to wait
+     * @return the execution result, or null
+     * @throws InterruptedException if we were interrupted by some other thread
+     */
+    Object waitForResult(long timeout) throws InterruptedException;
+}

src/helma/framework/core/ApplicationBean.java

@@ -22,6 +22,7 @@ import helma.util.CronJob;
 import helma.util.SystemMap;
 import helma.util.WrappedMap;
 import helma.framework.repository.*;
+import helma.framework.FutureResult;
 import helma.main.Server;
 
 import java.io.File;
@@ -33,7 +34,8 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 /**
- *
+ * Application bean that provides a handle to the scripting environment to
+ * application specific functionality.
  */
 public class ApplicationBean implements Serializable {
     Application app;
@@ -682,11 +684,11 @@ public class ApplicationBean implements Serializable {
      * this long, we will try to interrupt the invocation
      * @return an object with the properties described above
      */
-    public Object invokeAsync(Object thisObject,
+    public FutureResult invokeAsync(Object thisObject,
                               final Object function,
                               final Object[] args) {
         // default timeout of 15 minutes
-        return invokeAsync(thisObject, function, args, 60000L * 15);
+        return new AsyncInvoker(thisObject, function, args, 60000L * 15);
     }
 
     /**
@@ -712,16 +714,38 @@ public class ApplicationBean implements Serializable {
      * this long, we will try to interrupt the invocation
      * @return an object with the properties described above
      */
-    public Object invokeAsync(final Object thisObject,
-                              final Object function,
-                              final Object[] args,
-                              final long timeout) {
-        Thread thread = new Thread() {
+    public FutureResult invokeAsync(Object thisObject, Object function,
+                              Object[] args, long timeout) {
+        return new AsyncInvoker(thisObject, function, args, timeout);
+    }
+
+    /**
+     * Return a string presentation of this AppBean
+     * @return string description of this app bean object
+     */
+    public String toString() {
+        return "[Application " + app.getName() + "]";
+    }
+
+    class AsyncInvoker extends Thread implements FutureResult {
+
+        private Object thisObject;
+        private Object function;
+        private Object[] args;
+        private long timeout;
 
         private Object result;
         private Exception exception;
         private boolean running = true;
 
+        private AsyncInvoker(Object thisObj, Object func, Object[] args, long timeout) {
+            thisObject = thisObj;
+            function = func;
+            this.args = args;
+            this.timeout = timeout;
+            start();
+        }
+
         public void run() {
             RequestEvaluator reval = null;
             try {
@@ -779,16 +803,6 @@ public class ApplicationBean implements Serializable {
                     .append(", result: ").append(result).append(", exception: ")
                     .append(exception).append("}").toString();
         }
-        };
-        thread.start();
-        return thread;
-    }
 
-    /**
-     * Return a string presentation of this AppBean
-     * @return string description of this app bean object
-     */
-    public String toString() {
-        return "[Application " + app.getName() + "]";
     }
 }