jakarta.servlet.SingleThreadModel Maven / Gradle / Ivy
/*
* 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 jakarta.servlet;
/**
* Ensures that servlets handle only one request at a time. This interface has
* no methods.
*
* If a servlet implements this interface, you are guaranteed that no two
* threads will execute concurrently in the servlet's service
* method. The servlet container can make this guarantee by synchronizing access
* to a single instance of the servlet, or by maintaining a pool of servlet
* instances and dispatching each new request to a free servlet.
*
* Note that SingleThreadModel does not solve all thread safety issues. For
* example, session attributes and static variables can still be accessed by
* multiple requests on multiple threads at the same time, even when
* SingleThreadModel servlets are used. It is recommended that a developer take
* other means to resolve those issues instead of implementing this interface,
* such as avoiding the usage of an instance variable or synchronizing the block
* of the code accessing those resources. This interface is deprecated in
* Servlet API version 2.4.
*
* @deprecated As of Java Servlet API 2.4, with no direct replacement.
*/
@Deprecated
public interface SingleThreadModel {
// No methods
}