2 * Copyright (c) 2019 AT&T Intellectual Property. All rights reserved.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.akraino.validation.ui.config;
18 import java.lang.reflect.Field;
19 import java.util.Comparator;
20 import java.util.concurrent.ExecutorService;
21 import java.util.concurrent.PriorityBlockingQueue;
22 import java.util.concurrent.ThreadPoolExecutor;
23 import java.util.concurrent.TimeUnit;
25 import javax.servlet.ServletContext;
26 import javax.servlet.ServletException;
27 import javax.servlet.ServletRegistration;
29 import org.springframework.web.WebApplicationInitializer;
30 import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
31 import org.springframework.web.servlet.DispatcherServlet;
33 public class AppInitializer implements WebApplicationInitializer {
35 private static final int QUEUE_CAPACITY = 500;
36 private static final int EXECUTOR_SIZE = 20; // the number of threads to keep in the pool, even if
37 // they are idle, unless allowCoreThreadTimeOut is
39 private static final int EXECUTOR_MAX_SIZE = 20; // the maximum number of threads to allow in the pool
40 private static final int KEEPALIVE_TIME = 20; // when the number of threads is greater than the
41 // core, this is the maximum time that excess idle
42 // threads will wait for new tasks before
44 private static final PriorityBlockingQueue<Runnable> BLOCKING_QUEUE =
45 new PriorityBlockingQueue<Runnable>(QUEUE_CAPACITY, new CFRunnableComparator());
46 public static ExecutorService executorService = new ThreadPoolExecutor(EXECUTOR_SIZE,
47 EXECUTOR_MAX_SIZE, KEEPALIVE_TIME, TimeUnit.SECONDS, BLOCKING_QUEUE);
50 public void onStartup(ServletContext container) throws ServletException {
52 AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
53 ctx.register(AppConfig.class);
54 ctx.setServletContext(container);
56 ServletRegistration.Dynamic servlet = container.addServlet("dispatcher", new DispatcherServlet(ctx));
58 servlet.setLoadOnStartup(1);
59 servlet.addMapping("/");
63 private static class CFRunnableComparator implements Comparator<Runnable> {
65 @SuppressWarnings("unchecked")
66 public int compare(Runnable runnable1, Runnable runnable2) {
67 // T might be AsyncSupply, UniApply, etc., but we want to
68 // compare our original Runnables.
69 return ((Comparable) unwrap(runnable1)).compareTo(unwrap(runnable2));
72 private Object unwrap(Runnable runnable) {
74 Field field = runnable.getClass().getDeclaredField("fn");
75 field.setAccessible(true);
76 // NB: For performance-intensive contexts, you may want to
77 // cache these in a ConcurrentHashMap<Class<?>, Field>.
78 return field.get(runnable);
79 } catch (IllegalAccessException | NoSuchFieldException e) {
80 throw new IllegalArgumentException("Couldn't unwrap " + runnable, e);