abstractbuttontag.java

java 写的一个新闻发布系统

package org.jahia.taglibs.button;

import org.jahia.data.JahiaData;
import org.jahia.exceptions.JahiaException;
import org.jahia.services.usermanager.JahiaUser;
import org.jahia.taglibs.util.Utils;
import org.jahia.utils.JahiaConsole;

import java.io.*;
import java.util.*;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;


/**
 * Class AbstractButtonTag : defines common code for different buttons
 *
 * @author  Jerome Tamiotti
 */
public abstract class AbstractButtonTag extends TagSupport {

    public int doStartTag() {
		
        HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();
        JahiaData jData = (JahiaData) request.getAttribute("org.jahia.data.JahiaData");
        if (jData == null) {
            HashMap tempEngineMap = (HashMap) request.getAttribute("org.jahia.engines.EngineHashMap");
            jData                 = (JahiaData) tempEngineMap.get("jData");
        }
        // only used in rollover tags
        checkCounter(request);

        // makes a test on rights
        if (!testRights(jData)) {
            return SKIP_BODY;
        }
        String link = buildButton(jData, request);
        if (link != null) {
            try {
                JspWriter out = pageContext.getOut();
                out.print( link );
            } catch (IOException ioe) {
                JahiaConsole.println("AbstractButtonTag: doStartTag ", ioe.toString());
            }
        }
        return SKIP_BODY;
    }


    public void checkCounter(HttpServletRequest request) {
        // does not perform anything, defined only for rollover tags
        return;
    }

    public String buildButton (JahiaData jData, HttpServletRequest request) {

        String url = null;
        try {
            url = getLauncher(jData);
        } catch (JahiaException jex) {
            JahiaConsole.println("AbstractButtonTag: buildButton ", "Can not get launcher from subclass !");
            return null;
        }
		
		if ( url == null || url.trim().equals("") )
			return url;
			
        StringBuffer text = new StringBuffer( "<a " );
        String style = getStyle();
        if ( !style.equals("") ) {
            text.append( "class=\"" );
            text.append( style );
            text.append( "\" " );
        }
        text.append( "href=\"" );
        text.append( url );
        text.append( "\">" );
        text.append( Utils.insertContextPath( jData.gui().drawHttpJspContext(request), getTitle() ) );
        text.append( "</a>" );
        return text.toString();
    }


    // The following methods will be implemented in the real tags
    public abstract boolean testRights(JahiaData jData);

    public abstract String getLauncher(JahiaData jData) throws JahiaException;

    public abstract String getTitle();

    public abstract String getStyle();

}