--- /dev/null
+/*
+ * 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 javax.servlet;
+
+import java.io.IOException;
+
+/**
+ * Defines methods that all servlets must implement.
+ *
+ * <p>
+ * A servlet is a small Java program that runs within a Web server. Servlets
+ * receive and respond to requests from Web clients, usually across HTTP, the
+ * HyperText Transfer Protocol.
+ *
+ * <p>
+ * To implement this interface, you can write a generic servlet that extends
+ * <code>javax.servlet.GenericServlet</code> or an HTTP servlet that extends
+ * <code>javax.servlet.http.HttpServlet</code>.
+ *
+ * <p>
+ * This interface defines methods to initialize a servlet, to service requests,
+ * and to remove a servlet from the server. These are known as life-cycle
+ * methods and are called in the following sequence:
+ * <ol>
+ * <li>The servlet is constructed, then initialized with the <code>init</code>
+ * method.
+ * <li>Any calls from clients to the <code>service</code> method are handled.
+ * <li>The servlet is taken out of service, then destroyed with the
+ * <code>destroy</code> method, then garbage collected and finalized.
+ * </ol>
+ *
+ * <p>
+ * In addition to the life-cycle methods, this interface provides the
+ * <code>getServletConfig</code> method, which the servlet can use to get any
+ * startup information, and the <code>getServletInfo</code> method, which allows
+ * the servlet to return basic information about itself, such as author,
+ * version, and copyright.
+ *
+ * @see GenericServlet
+ * @see javax.servlet.http.HttpServlet
+ */
+public interface Servlet {
+
+ /**
+ * Called by the servlet container to indicate to a servlet that the servlet
+ * is being placed into service.
+ *
+ * <p>
+ * The servlet container calls the <code>init</code> method exactly once
+ * after instantiating the servlet. The <code>init</code> method must
+ * complete successfully before the servlet can receive any requests.
+ *
+ * <p>
+ * The servlet container cannot place the servlet into service if the
+ * <code>init</code> method
+ * <ol>
+ * <li>Throws a <code>ServletException</code>
+ * <li>Does not return within a time period defined by the Web server
+ * </ol>
+ *
+ *
+ * @param config
+ * a <code>ServletConfig</code> object containing the servlet's
+ * configuration and initialization parameters
+ *
+ * @exception ServletException
+ * if an exception has occurred that interferes with the
+ * servlet's normal operation
+ *
+ * @see UnavailableException
+ * @see #getServletConfig
+ */
+ public void init(ServletConfig config) throws ServletException;
+
+ /**
+ *
+ * Returns a {@link ServletConfig} object, which contains initialization and
+ * startup parameters for this servlet. The <code>ServletConfig</code>
+ * object returned is the one passed to the <code>init</code> method.
+ *
+ * <p>
+ * Implementations of this interface are responsible for storing the
+ * <code>ServletConfig</code> object so that this method can return it. The
+ * {@link GenericServlet} class, which implements this interface, already
+ * does this.
+ *
+ * @return the <code>ServletConfig</code> object that initializes this
+ * servlet
+ *
+ * @see #init
+ */
+ public ServletConfig getServletConfig();
+
+ /**
+ * Called by the servlet container to allow the servlet to respond to a
+ * request.
+ *
+ * <p>
+ * This method is only called after the servlet's <code>init()</code> method
+ * has completed successfully.
+ *
+ * <p>
+ * The status code of the response always should be set for a servlet that
+ * throws or sends an error.
+ *
+ *
+ * <p>
+ * Servlets typically run inside multithreaded servlet containers that can
+ * handle multiple requests concurrently. Developers must be aware to
+ * synchronize access to any shared resources such as files, network
+ * connections, and as well as the servlet's class and instance variables.
+ * More information on multithreaded programming in Java is available in <a
+ * href
+ * ="http://java.sun.com/Series/Tutorial/java/threads/multithreaded.html">
+ * the Java tutorial on multi-threaded programming</a>.
+ *
+ *
+ * @param req
+ * the <code>ServletRequest</code> object that contains the
+ * client's request
+ *
+ * @param res
+ * the <code>ServletResponse</code> object that contains the
+ * servlet's response
+ *
+ * @exception ServletException
+ * if an exception occurs that interferes with the servlet's
+ * normal operation
+ *
+ * @exception IOException
+ * if an input or output exception occurs
+ */
+ public void service(ServletRequest req, ServletResponse res)
+ throws ServletException, IOException;
+
+ /**
+ * Returns information about the servlet, such as author, version, and
+ * copyright.
+ *
+ * <p>
+ * The string that this method returns should be plain text and not markup
+ * of any kind (such as HTML, XML, etc.).
+ *
+ * @return a <code>String</code> containing servlet information
+ */
+ public String getServletInfo();
+
+ /**
+ * Called by the servlet container to indicate to a servlet that the servlet
+ * is being taken out of service. This method is only called once all
+ * threads within the servlet's <code>service</code> method have exited or
+ * after a timeout period has passed. After the servlet container calls this
+ * method, it will not call the <code>service</code> method again on this
+ * servlet.
+ *
+ * <p>
+ * This method gives the servlet an opportunity to clean up any resources
+ * that are being held (for example, memory, file handles, threads) and make
+ * sure that any persistent state is synchronized with the servlet's current
+ * state in memory.
+ */
+ public void destroy();
+}
projects / gigi.git / blobdiff