Quadcap Embeddable Server

com/quadcap/http/servlets/jsp/TagJspUseBean.java

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package com.quadcap.http.servlets.jsp;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.PrintWriter;

import java.util.Hashtable;

import org.xml.sax.AttributeList;

import com.quadcap.util.Debug;

/**
 * 
 * Implementation of the <b>&lt;jsp:useBean&gt;</b> tag.
 *
 * @author Stan Bailes
 */
public class TagJspUseBean extends TagJsp {
    static Hashtable            scopes          = new Hashtable();
    static {
        scopes.put("page", "PageContext.PAGE_SCOPE");
        scopes.put("request", "PageContext.REQUEST_SCOPE");
        scopes.put("session", "PageContext.SESSION_SCOPE");
        scopes.put("application", "PageContext.APPLICATION_SCOPE");
    }

    public TagJspUseBean() {}

    public TagJspUseBean(TagContext context) {
        super(context);
    }

    public TagInstance makeInstance(TagContext context) {
        return new TagJspUseBean(context);
    }

        throws JspException
    {
        super.doStartTag(tagName, attributes);
        PrintWriter w = context.getPrintWriter();
        String id = attributes.getValue("id");
        String clazz = attributes.getValue("class");
        String scope = attributes.getValue("scope");
        if (scope == null || scope.equals("")) scope = "page";
        String scopeVal = (String)scopes.get(scope);
        if (scopeVal == null) {
            throw new JspException("Invalid scope for <jsp:useBean: " +
                                   scope);
        }
        // clazz id = null;
        w.print("        ");
        w.print(clazz);
        w.print(" ");
        w.print(id);
        w.println(" = null;");

        // synchronized (this) {
        w.println("        synchronized (this) {");

        //     id = (clazz)pageContext.getAttribute("id", SCOPE);
        w.print  ("            ");
        w.print(id);
        w.print(" = (");
        w.print(clazz);
        w.print(")pageContext.getAttribute(\"");
        w.print(id);
        w.print("\", ");
        w.print(scopeVal);
        w.println(");");

        //     if (id == null) {
        w.print  ("            if (");
        w.print(id);
        w.println(" == null) {");

        //         id = (clazz)Class.forName("clazz").newInstance();
        w.print  ("                ");
        w.print(id);
        w.print(" = (");
        w.print(clazz);
        w.print(")Class.forName(\"");
        w.print(clazz);
        w.println("\").newInstance();");

        //         pageContext.setAttribute("id", id, SCOPE);
        w.print  ("                pageContext.setAttribute(\"");
        w.print(id);
        w.print("\", ");
        w.print(id);
        w.print(", ");
        w.print(scopeVal);
        w.println(");");

        //     }
        w.println("            }");

        // }
        w.println("        }"); 
    }

    public void doCharacters(char[] ch, int off, int cnt) throws JspException {
        doTemplateCharacters(ch, off, cnt);
    }
}