pi3jspfactory.java

mini http server,可以集成嵌入到程序中,实现简单的web功能

/*____________________________________________________________________________*\
 *

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 *____________________________________________________________________________*|
 *
 * $Source: /cvsroot/pi3web/Pi3Web_200/Source/Servlet/org/pi3/jsp/core/Pi3JspFactory.java,v $
 * $Date: 2003/05/13 18:42:20 $
 *
 Description:
	Implementation of jsp API JspFactory interface.

\*____________________________________________________________________________*/
 
package org.pi3.jsp.core;

import javax.servlet.Servlet;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.jsp.JspFactory;
import javax.servlet.jsp.JspEngineInfo;
import javax.servlet.jsp.PageContext;

/**
 * <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>
 * <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>
 */

final public class Pi3JspFactory extends JspFactory {

    /**
     * <p>
     * obtains an instance of an implementation dependent 
     * javax.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 config    the ServletConfig for 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, PageContext.NO_BUFFER if no buffer,
     *			PageContext.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 javax.servlet.jsp.PageContext
     */

    public PageContext getPageContext(
					Servlet         servlet,
					ServletRequest  request,
					ServletResponse response,
					String          errorPageURL,
					boolean         needsSession,
					int             buffer,
					boolean         autoflush) {
        try {
            Pi3PageContext pc =  new Pi3PageContext();
            pc.initialize(servlet, request, response, errorPageURL, 
                          needsSession, buffer, autoflush);
            return (PageContext)pc;
        } catch (Exception ex) {
            /* FIXME: need to do something reasonable here!! */
            ex.printStackTrace();
            return null;
        }
    }


    static JspEngineInfo info = new Pi3JspEngineInfo();

    /**
     * <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 void releasePageContext(PageContext pc) {
        pc.release();
    };

    /**
     * <p>
     * called to get implementation-specific information on the current JSP engine
     * </p>
     *
     * @return a JspEngineInfo object describing the current JSP engine
     */
    
    public JspEngineInfo getEngineInfo() { return info; };
}