selecttag.java

一个实用工具类

/*
 * Copyright (C) butor.com. All rights reserved.
 *
 * This software is published under the terms of the GNU Library General
 * Public License (GNU LGPL), a copy of which has been included with this
 * distribution in the LICENSE.txt file. 
 */


package org.butor.web.taglib.html;

import java.lang.reflect.InvocationTargetException;

import javax.servlet.jsp.JspException;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts.util.RequestUtils;
import org.apache.struts.util.ResponseUtils;
import org.butor.web.action.IButorActionForm;

/**
 * @author nacroaz
 *
 * To change this generated comment edit the template variable "typecomment":
 * Window>Preferences>Java>Templates.
 */
public class SelectTag extends org.apache.struts.taglib.html.SelectTag {
	protected boolean f_isEnable = true;
	protected String saveOnDisable = "1";
		
	/**
     * Render the beginning of this form.
     * Indexed property since 1.1
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {
	   	// Find and check the form bean	  
    	Object o = RequestUtils.lookup(pageContext, name, null);    	
        if (! (o instanceof IButorActionForm)) {
			ResponseUtils.write(pageContext, "The form bean must be an instance of ButorActionForm !!!");  
			return SKIP_BODY;
        }        
        IButorActionForm form = (IButorActionForm) o;
        
        // If property is enable, use super class definition        
        if ((f_isEnable = form.getEnabled(property))) {        	 
        	return super.doStartTag();
        } else {
        	// the property is disable, we must calculate the match values 
        	// we will actually be using
	        if (value != null) {
	            match = new String[1];
	            match[0] = value;
	        } else {
	            Object bean = pageContext.findAttribute(name);
	            if (bean == null) {
	                JspException e = new JspException
	                    (messages.getMessage("getter.bean", name));
	                RequestUtils.saveException(pageContext, e);
	                throw e;
	            }
	            try {
	                match = BeanUtils.getArrayProperty(bean, property);
	                if (match == null) {
	                    match = new String[0];
                    }
	            } catch (IllegalAccessException e) {
	                RequestUtils.saveException(pageContext, e);
	                throw new JspException
	                    (messages.getMessage("getter.access", property, name));
	            } catch (InvocationTargetException e) {
	                Throwable t = e.getTargetException();
	                RequestUtils.saveException(pageContext, t);
	                throw new JspException
	                    (messages.getMessage("getter.result",
	                                         property, t.toString()));
	            } catch (NoSuchMethodException e) {
	                RequestUtils.saveException(pageContext, e);
	                throw new JspException
	                    (messages.getMessage("getter.method", property, name));
	            }
	        }        	
        }
        
        if (saveOnDisable == null) {
        	saveOnDisable = "1";	
        }
        
        // Continue processing this page
        return (EVAL_BODY_BUFFERED);
    }
    
   /**
     * Render the end of this form.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doEndTag() throws JspException {
        // If property is enable, use super class definition     	
    	if (f_isEnable) {
    		return super.doEndTag();	
    	}

        // Render a tag representing the end of our current form
        StringBuffer results = new StringBuffer();
        if (saveBody != null) {
            results.append(saveBody);
        }

        // Print this value to our output writer
        ResponseUtils.write(pageContext, results.toString());

        // Continue processing this page
        return (EVAL_PAGE);
    } 
       
	/**
	 * Returns the saveOnDisable.
	 * @return String
	 */
	public String getSaveOnDisable() {
		return saveOnDisable;
	}

	/**
	 * Sets the saveOnDisable.
	 * @param saveOnDisable The saveOnDisable to set
	 */
	public void setSaveOnDisable(String saveOnDisable) {
		this.saveOnDisable = saveOnDisable;
	}

}