X-Git-Url: https://code.wpia.club/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fservlet-api%2Fjavax%2Fservlet%2FGenericServlet.java;fp=lib%2Fservlet-api%2Fjavax%2Fservlet%2FGenericServlet.java;h=f040cb7a08dc60a102063115b9866bffc1d62b9e;hb=454e6afd89d77c1005eae4838e74e82fae759668;hp=0000000000000000000000000000000000000000;hpb=c2ca9ecd6facc79051cca2e6d46f211dfd54c7b9;p=gigi.git diff --git a/lib/servlet-api/javax/servlet/GenericServlet.java b/lib/servlet-api/javax/servlet/GenericServlet.java new file mode 100644 index 00000000..f040cb7a --- /dev/null +++ b/lib/servlet-api/javax/servlet/GenericServlet.java @@ -0,0 +1,238 @@ +/* + * 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; +import java.util.Enumeration; + +/** + * Defines a generic, protocol-independent servlet. To write an HTTP servlet for + * use on the Web, extend {@link javax.servlet.http.HttpServlet} instead. + *

+ * GenericServlet implements the Servlet and + * ServletConfig interfaces. GenericServlet may be + * directly extended by a servlet, although it's more common to extend a + * protocol-specific subclass such as HttpServlet. + *

+ * GenericServlet makes writing servlets easier. It provides simple + * versions of the lifecycle methods init and destroy + * and of the methods in the ServletConfig interface. + * GenericServlet also implements the log method, + * declared in the ServletContext interface. + *

+ * To write a generic servlet, you need only override the abstract + * service method. + */ +public abstract class GenericServlet implements Servlet, ServletConfig, + java.io.Serializable { + + private static final long serialVersionUID = 1L; + + private transient ServletConfig config; + + /** + * Does nothing. All of the servlet initialization is done by one of the + * init methods. + */ + public GenericServlet() { + // NOOP + } + + /** + * Called by the servlet container to indicate to a servlet that the servlet + * is being taken out of service. See {@link Servlet#destroy}. + */ + @Override + public void destroy() { + // NOOP by default + } + + /** + * Returns a String containing the value of the named + * initialization parameter, or null if the parameter does not + * exist. See {@link ServletConfig#getInitParameter}. + *

+ * This method is supplied for convenience. It gets the value of the named + * parameter from the servlet's ServletConfig object. + * + * @param name + * a String specifying the name of the + * initialization parameter + * @return String a String containing the value of the + * initialization parameter + */ + @Override + public String getInitParameter(String name) { + return getServletConfig().getInitParameter(name); + } + + /** + * Returns the names of the servlet's initialization parameters as an + * Enumeration of String objects, or an empty + * Enumeration if the servlet has no initialization parameters. + * See {@link ServletConfig#getInitParameterNames}. + *

+ * This method is supplied for convenience. It gets the parameter names from + * the servlet's ServletConfig object. + * + * @return Enumeration an enumeration of String objects + * containing the names of the servlet's initialization parameters + */ + @Override + public Enumeration getInitParameterNames() { + return getServletConfig().getInitParameterNames(); + } + + /** + * Returns this servlet's {@link ServletConfig} object. + * + * @return ServletConfig the ServletConfig object that + * initialized this servlet + */ + @Override + public ServletConfig getServletConfig() { + return config; + } + + /** + * Returns a reference to the {@link ServletContext} in which this servlet + * is running. See {@link ServletConfig#getServletContext}. + *

+ * This method is supplied for convenience. It gets the context from the + * servlet's ServletConfig object. + * + * @return ServletContext the ServletContext object passed to + * this servlet by the init method + */ + @Override + public ServletContext getServletContext() { + return getServletConfig().getServletContext(); + } + + /** + * Returns information about the servlet, such as author, version, and + * copyright. By default, this method returns an empty string. Override this + * method to have it return a meaningful value. See + * {@link Servlet#getServletInfo}. + * + * @return String information about this servlet, by default an empty string + */ + @Override + public String getServletInfo() { + return ""; + } + + /** + * Called by the servlet container to indicate to a servlet that the servlet + * is being placed into service. See {@link Servlet#init}. + *

+ * This implementation stores the {@link ServletConfig} object it receives + * from the servlet container for later use. When overriding this form of + * the method, call super.init(config). + * + * @param config + * the ServletConfig object that contains + * configuration information for this servlet + * @exception ServletException + * if an exception occurs that interrupts the servlet's + * normal operation + * @see UnavailableException + */ + @Override + public void init(ServletConfig config) throws ServletException { + this.config = config; + this.init(); + } + + /** + * A convenience method which can be overridden so that there's no need to + * call super.init(config). + *

+ * Instead of overriding {@link #init(ServletConfig)}, simply override this + * method and it will be called by + * GenericServlet.init(ServletConfig config). The + * ServletConfig object can still be retrieved via + * {@link #getServletConfig}. + * + * @exception ServletException + * if an exception occurs that interrupts the servlet's + * normal operation + */ + public void init() throws ServletException { + // NOOP by default + } + + /** + * Writes the specified message to a servlet log file, prepended by the + * servlet's name. See {@link ServletContext#log(String)}. + * + * @param msg + * a String specifying the message to be written to + * the log file + */ + public void log(String msg) { + getServletContext().log(getServletName() + ": " + msg); + } + + /** + * Writes an explanatory message and a stack trace for a given + * Throwable exception to the servlet log file, prepended by + * the servlet's name. See {@link ServletContext#log(String, Throwable)}. + * + * @param message + * a String that describes the error or exception + * @param t + * the java.lang.Throwable error or exception + */ + public void log(String message, Throwable t) { + getServletContext().log(getServletName() + ": " + message, t); + } + + /** + * Called by the servlet container to allow the servlet to respond to a + * request. See {@link Servlet#service}. + *

+ * This method is declared abstract so subclasses, such as + * HttpServlet, must override it. + * + * @param req + * the ServletRequest object that contains the + * client's request + * @param res + * the ServletResponse object that will contain the + * servlet's response + * @exception ServletException + * if an exception occurs that interferes with the servlet's + * normal operation occurred + * @exception IOException + * if an input or output exception occurs + */ + @Override + public abstract void service(ServletRequest req, ServletResponse res) + throws ServletException, IOException; + + /** + * Returns the name of this servlet instance. See + * {@link ServletConfig#getServletName}. + * + * @return the name of this servlet instance + */ + @Override + public String getServletName() { + return config.getServletName(); + } +}