WW-4874 Refactors technology name, servlet3, to asset name, async

plugins/async/src/main/java/org/apache/struts2/async/AsyncAction.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.async;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.Executor;
+
+/**
+ * A {@link Callable} with a timeout value and an {@link Executor}.
+ *
+ * @since 2.5.14
+ */
+public class AsyncAction implements Callable {
+    private Callable callable;
+    private Long timeout;
+    private Executor executor;
+
+    public AsyncAction(Callable callable) {
+        this.callable = callable;
+    }
+
+    public AsyncAction(long timeout, Callable callable) {
+        this(callable);
+        this.timeout = timeout;
+    }
+
+    public AsyncAction(Executor executor, Callable callable) {
+        this(callable);
+        this.executor = executor;
+    }
+
+    public AsyncAction(long timeout, Executor executor, Callable callable) {
+        this(timeout, callable);
+        this.executor = executor;
+    }
+
+    public Long getTimeout() {
+        return timeout;
+    }
+
+    public Executor getExecutor() {
+        return executor;
+    }
+
+    @Override
+    public Object call() throws Exception {
+        return callable.call();
+    }
+}

plugins/async/src/main/java/org/apache/struts2/async/DefaultAsyncManager.java

@@ -0,0 +1,149 @@
+/*
+ * 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.async;
+
+import com.opensymphony.xwork2.AsyncManager;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.struts2.ServletActionContext;
+
+import javax.servlet.AsyncContext;
+import javax.servlet.AsyncEvent;
+import javax.servlet.AsyncListener;
+import javax.servlet.http.HttpServletRequest;
+import java.io.IOException;
+import java.util.concurrent.Callable;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Implements {@link AsyncManager} to add support for invoke async actions via Servlet 3's API.
+ *
+ * @since 2.5.14
+ */
+public class DefaultAsyncManager implements AsyncManager, AsyncListener {
+    private static final Logger LOG = LogManager.getLogger(DefaultAsyncManager.class);
+    private static final AtomicInteger threadCount = new AtomicInteger(0);
+
+    private AsyncContext asyncContext;
+    private boolean asyncActionStarted;
+    private Boolean asyncCompleted;
+    private Object asyncActionResult;
+
+    @Override
+    public void invokeAsyncAction(final Callable asyncAction) {
+        if (asyncActionStarted) {
+            return;
+        }
+
+        Long timeout = null;
+        Executor executor = null;
+        if (asyncAction instanceof AsyncAction) {
+            AsyncAction customAsyncAction = (AsyncAction) asyncAction;
+            timeout = customAsyncAction.getTimeout();
+            executor = customAsyncAction.getExecutor();
+        }
+
+        HttpServletRequest req = ServletActionContext.getRequest();
+        asyncActionResult = null;
+        asyncCompleted = false;
+
+        if (asyncContext == null || !req.isAsyncStarted()) {
+            asyncContext = req.startAsync(req, ServletActionContext.getResponse());
+            asyncContext.addListener(this);
+            if (timeout != null) {
+                asyncContext.setTimeout(timeout);
+            }
+        }
+        asyncActionStarted = true;
+        LOG.debug("Async processing started for " + asyncContext);
+
+        final Runnable task = new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    setAsyncActionResultAndDispatch(asyncAction.call());
+                } catch (Throwable e) {
+                    setAsyncActionResultAndDispatch(e);
+                }
+            }
+        };
+        if (executor != null) {
+            executor.execute(task);
+        } else {
+            final Thread thread = new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        task.run();
+                    } finally {
+                        threadCount.decrementAndGet();
+                    }
+                }
+            }, this.getClass().getSimpleName() + "-" + threadCount.incrementAndGet());
+            thread.start();
+        }
+    }
+
+    private void setAsyncActionResultAndDispatch(Object asyncActionResult) {
+        this.asyncActionResult = asyncActionResult;
+
+        String log = "Async result [" + asyncActionResult + "] of " + asyncContext;
+        if (asyncCompleted) {
+            LOG.error(log + " - could not complete result executing due to timeout or network error");
+        } else {
+            LOG.debug(log + " - dispatching request to execute result in container");
+            asyncContext.dispatch();
+        }
+    }
+
+    @Override
+    public boolean hasAsyncActionResult() {
+        return asyncActionResult != null;
+    }
+
+    @Override
+    public Object getAsyncActionResult() {
+        return asyncActionResult;
+    }
+
+    @Override
+    public void onComplete(AsyncEvent asyncEvent) throws IOException {
+        asyncContext = null;
+        asyncCompleted = true;
+    }
+
+    @Override
+    public void onTimeout(AsyncEvent asyncEvent) throws IOException {
+        LOG.debug("Processing timeout for " + asyncEvent.getAsyncContext());
+        setAsyncActionResultAndDispatch("timeout");
+    }
+
+    @Override
+    public void onError(AsyncEvent asyncEvent) throws IOException {
+        Throwable e = asyncEvent.getThrowable();
+        LOG.error("Processing error for " + asyncEvent.getAsyncContext(), e);
+        setAsyncActionResultAndDispatch(e);
+    }
+
+    @Override
+    public void onStartAsync(AsyncEvent asyncEvent) throws IOException {
+
+    }
+}

plugins/async/src/main/resources/struts-plugin.xml

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+<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+/*
+ * 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.
+ */
+-->
+<!DOCTYPE struts PUBLIC
+        "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
+        "http://struts.apache.org/dtds/struts-2.5.dtd">
+
+<struts>
+    <bean type="com.opensymphony.xwork2.AsyncManager" name="default"
+          class="org.apache.struts2.async.DefaultAsyncManager" scope="prototype" />
+</struts>