2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 package javax.servlet;
20 * Ensures that servlets handle only one request at a time. This interface has
23 * If a servlet implements this interface, you are <i>guaranteed</i> that no two
24 * threads will execute concurrently in the servlet's <code>service</code>
25 * method. The servlet container can make this guarantee by synchronizing access
26 * to a single instance of the servlet, or by maintaining a pool of servlet
27 * instances and dispatching each new request to a free servlet.
29 * Note that SingleThreadModel does not solve all thread safety issues. For
30 * example, session attributes and static variables can still be accessed by
31 * multiple requests on multiple threads at the same time, even when
32 * SingleThreadModel servlets are used. It is recommended that a developer take
33 * other means to resolve those issues instead of implementing this interface,
34 * such as avoiding the usage of an instance variable or synchronizing the block
35 * of the code accessing those resources. This interface is deprecated in
36 * Servlet API version 2.4.
38 * @deprecated As of Java Servlet API 2.4, with no direct replacement.
40 @SuppressWarnings("dep-ann")
41 // Spec API does not use @Deprecated
42 public interface SingleThreadModel {