nestedroottag.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

/*
 * $Header: /sfroot/cvs/esimple/src/core/com/esimple/framework/web/taglib/nested/NestedRootTag.java,v 1.1.1.1 2004/09/08 06:38:22 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:22 $
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 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", "Struts", 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 [e-mail].
 *
 * 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 com.esimple.framework.web.taglib.nested;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;

import org.apache.struts.util.ResponseUtils;

/**
 * NestedRootTag.
 *
 * The only other addition in this nested suite of tags.
 * This tag allows for a nested structure to start without relying on the bean
 * and workings of the FormTag. Useful for view pages that don't update when
 * returning to the server, or use hyperlinks rather than form submits.
 *
 * The Bean that it uses can come out of a jsp:useBean tag or define another
 * bean that's already in scope. As long as the other Struts tags can find the
 * bean by name, it'll work.
 *
 * It's simply recognised by the helper class and it's property is added to the
 * nesting list.
 *
 * @author Arron Bates
 * @since Struts 1.1
 * @version $Revision: 1.1.1.1 $ $Date: 2004/09/08 06:38:22 $
 */
public class NestedRootTag extends BodyTagSupport implements NestedNameSupport {

  /** Getter method for the <i>property</i> property
   * @return String value of the property property
   */
  public String getProperty() {
    return "";
  }
  /** Setter method for the <i>property</i> property
   * @param property new value for the property property
   */
  public void setProperty(String property) {}

  /** Getter method for the <i>name</i> property
   * @return String value of the name property
   */
  public String getName() {
    return this.name;
  }
  /** Setter method for the <i>name</i> property
   * @param name new value for the name property
   */
  public void setName(String name) {
    this.name = name;
  }

  /**
   * Overriding method of the heart of the tag. Gets the relative property
   * and tells the JSP engine to evaluate its body content.
   *
   * @return int JSP continuation directive.
   */
  public int doStartTag() throws JspException {
    /* set the nested reference for possible inclusions etc */
    HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();

    // get al the originals
    originalName = name;
    originalNesting = NestedPropertyHelper.getCurrentProperty(request);
    originalNestingName = NestedPropertyHelper.getCurrentName(request, this);

    // set what we have to
    if (name != null) {
      NestedPropertyHelper.setProperty(request, "");
      NestedPropertyHelper.setName(request, this.name);
    }

    // do the JSP thing
    return (EVAL_BODY_TAG);
  }

  /**
   * Render the resulting content evaluation.
   *
   * @return int JSP continuation directive.
   */
  public int doAfterBody() throws JspException {
    /* Render the output */
    if (bodyContent != null) {
      ResponseUtils.writePrevious(pageContext, bodyContent.getString());
      bodyContent.clearBody();
    }

    return (SKIP_BODY);
  }

  /**
   * Evaluate the rest of the page
   *
   * @return int JSP continuation directive.
   */
  public int doEndTag() throws JspException {
    /* reset the reference */
    HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();

    if (originalNesting == null) {
      NestedPropertyHelper.deleteReference(request);
    } else {
      NestedPropertyHelper.setName(request, originalNestingName);
      NestedPropertyHelper.setProperty(request, "nestOne");
    }
    this.name = originalName;

    return (EVAL_PAGE);
  }


  /**
   * JSP method to release all resources held by the tag.
   */
  public void release() {
    super.release();
    this.name = null;
    this.originalName = null;
    this.originalNesting = null;
    this.originalNestingName = null;
  }

  /* usual member variables */
  private String name = null;
  private String originalName = "";
  private String originalNesting = "";
  private String originalNestingName = "";
}