/*
* 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.jsp;
import jakarta.servlet.Servlet;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
/**
* <p>
* The JspFactory is an abstract class that defines a number of factory methods available to a JSP page at runtime for
* the purposes of creating instances of various interfaces and classes used to support the JSP implementation.
* <p>
* A conformant JSP Engine implementation will, during it's initialization instantiate an implementation dependent
* subclass of this class, and make it globally available for use by JSP implementation classes by registering the
* instance created with this class via the static <code> setDefaultFactory() </code> method.
* <p>
* The PageContext and the JspEngineInfo classes are the only implementation-dependent classes that can be created from
* the factory.
* <p>
* JspFactory objects should not be used by JSP page authors.
*/
public abstract class JspFactory {
private static volatile JspFactory deflt = null;
/**
* Sole constructor. (For invocation by subclass constructors, typically implicit.)
*/
public JspFactory() {
// NOOP by default
}
/**
* <p>
* set the default factory for this implementation. It is illegal for any principal other than the JSP Engine
* runtime to call this method.
* </p>
*
* @param deflt The default factory implementation
*/
public static void setDefaultFactory(JspFactory deflt) {
JspFactory.deflt = deflt;
}
/**
* Returns the default factory for this implementation.
*
* @return the default factory for this implementation
*/
public static JspFactory getDefaultFactory() {
return deflt;
}
/**
* <p>
* obtains an instance of an implementation dependent jakarta.servlet.jsp.PageContext abstract class for the calling
* Servlet and currently pending request and response.
* </p>
* <p>
* This method is typically called early in the processing of the _jspService() method of a JSP implementation class
* in order to obtain a PageContext object for the request being processed.
* </p>
* <p>
* Invoking this method shall result in the PageContext.initialize() method being invoked. The PageContext returned
* is properly initialized.
* </p>
* <p>
* All PageContext objects obtained via this method shall be released by invoking releasePageContext().
* </p>
*
* @param servlet the requesting servlet
* @param request the current request pending on the servlet
* @param response the current response pending on the servlet
* @param errorPageURL the URL of the error page for the requesting JSP, or null
* @param needsSession true if the JSP participates in a session
* @param buffer size of buffer in bytes, {@link JspWriter#NO_BUFFER} if no buffer,
* {@link JspWriter#DEFAULT_BUFFER} if implementation default.
* @param autoflush should the buffer autoflush to the output stream on buffer overflow, or throw an IOException?
*
* @return the page context
*
* @see jakarta.servlet.jsp.PageContext
*/
public abstract PageContext getPageContext(Servlet servlet, ServletRequest request, ServletResponse response,
String errorPageURL, boolean needsSession, int buffer, boolean autoflush);
/**
* <p>
* called to release a previously allocated PageContext object. Results in PageContext.release() being invoked. This
* method should be invoked prior to returning from the _jspService() method of a JSP implementation class.
* </p>
*
* @param pc A PageContext previously obtained by getPageContext()
*/
public abstract void releasePageContext(PageContext pc);
/**
* <p>
* called to get implementation-specific information on the current JSP engine.
* </p>
*
* @return a JspEngineInfo object describing the current JSP engine
*/
public abstract JspEngineInfo getEngineInfo();
/**
* <p>
* Obtain the <code>JspApplicationContext</code> instance that was associated within the passed
* <code>ServletContext</code> for this web application.
* </p>
*
* @param context the current web application's <code>ServletContext</code>
*
* @return <code>JspApplicationContext</code> instance
*
* @since JSP 2.1
*/
public abstract JspApplicationContext getJspApplicationContext(ServletContext context);
}