cvs commit: jakarta-taglibs/request/src/org/apache/taglibs/request ExistsQueryStringTag.java

[gl...@locus.apache.org]

glenn       00/10/15 11:07:41

  Added:       request/src/org/apache/taglibs/request
                        ExistsQueryStringTag.java
  Log:
  Added support for breaking out querystring
  
  Revision  Changes    Path
  1.1                  jakarta-taglibs/request/src/org/apache/taglibs/request/ExistsQueryStringTag.java
  
  Index: ExistsQueryStringTag.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-taglibs/request/src/org/apache/taglibs/request/ExistsQueryStringTag.java,v 1.1 2000/10/15 18:07:41 glenn Exp $
   * $Revision: 1.1 $
   * $Date: 2000/10/15 18:07:41 $
   *
   * ====================================================================
   *
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 1999 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.taglibs.request;
  
  import java.util.*;
  import javax.servlet.*;
  import javax.servlet.http.*;
  import javax.servlet.jsp.*;
  import javax.servlet.jsp.tagext.*;
  
  /**
   * JSP Tag <b>existsquerystring</b>, used to determine if an HttpServletRequest
   * querystring parameter exists.
   * <p>
   * Includes the body of the tag if the querystring parameter exists.
   * <p>
   * You can set the optional tag querystring <b>value</b> to <i>true</i> or
   * <i>false</i>.  The body of the tag is included if existsquerystring matches
   * the value.
   * <p>
   * JSP Tag Lib Descriptor
   * <p><pre>
   * &lt;name&gt;existsquerystring&lt;/name&gt;
   * &lt;tagclass&gt;org.apache.taglibs.request.ExistsQueryStringTag&lt;/tagclass&gt;
   * &lt;bodycontent&gt;JSP&lt;/bodycontent&gt;
   * &lt;info&gt;Includes the body of the tag if the request querystring parameter exists.&lt;/info&gt;
   *   &lt;attribute&gt;
   *     &lt;name&gt;name&lt;/name&gt;
   *     &lt;required&gt;true&lt;/required&gt;
   *     &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
   *   &lt;/attribute&gt;
   *   &lt;attribute&gt;
   *     &lt;name&gt;value&lt;/name&gt;
   *     &lt;required&gt;false&lt;/required&gt;
   *     &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
   *   &lt;/attribute&gt;
   * </pre>
   *
   * @author Glenn Nielsen
   */
  
  public class ExistsQueryStringTag extends TagSupport
  {
      private String name = null;
      private Boolean value = null;
  
      /**
       * Includes the body of the tag if the request querystring parameter exists.
       *
       * @return SKIP_BODY if existsquerystring doesn't match value, EVAL_BODY_include if existsquerystring matches value
       */
      public int doStartTag() throws JspException
      {
  	boolean result = false;
  	String query =
  	    ((HttpServletRequest)pageContext.getRequest()).getQueryString();
  
  	StringTokenizer st = new StringTokenizer(query,"&");
  	String prefix = name + "=";
  	while( st.hasMoreTokens() ) {
  	    if( st.nextToken().startsWith(prefix) ) {
  		result = true;
  		break;
  	    }
  	}
  
  	if( value == null ) {
  	   if( result )
  		return EVAL_BODY_INCLUDE;
  	   return SKIP_BODY;
  	}
  	if( value.booleanValue() == result )
  	    return EVAL_BODY_INCLUDE;
  	return SKIP_BODY;
      }
  
      public void setName(String str)
      {   
  	name = str;
      }
  
      public void setValue(String str)
      {
  	value = new Boolean(str);
      }
  
  }