messageresourcesmenudisplayer.java

Struts Menu这是为基于JSP和Struts的应用程序提供的Web菜单框架。菜单可以在一个XML文件中定义

/*
 * MessageResourcesMenuDisplayer.java
 *
 * Created on February 6, 2001, 3:34 PM
 */
package net.sf.navigator.displayer;

import java.io.IOException;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

import javax.servlet.jsp.JspException;

import net.sf.navigator.menu.MenuComponent;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.util.MessageResources;


/**
 *
 * @author  ssayles
 * @version
 */
public abstract class MessageResourcesMenuDisplayer
    extends AbstractMenuDisplayer {
    
    private static Log log = LogFactory.getLog(MessageResourcesMenuDisplayer.class);
    
    //~ Instance fields ========================================================

    protected Object messages = null;
    protected Locale locale = null;

    //~ Methods ================================================================

    public Locale getLocale() {
        return locale;
    }

    public void setLocale(Locale locale) {
        this.locale = locale;
    }

    public Object getMessageResources() {
        return messages;
    }

    public void setMessageResources(Object messages) {
        this.messages = messages;
    }

    /**
     * Get the title key from the bundle (if it exists).  This method
     * is public to expose it to Velocity.
     * 
     * @param key the key
     */
    public String getMessage(String key) {
        String message = null;
        
        if (messages != null && (messages instanceof MessageResources)) {   
            if (log.isDebugEnabled()) {
            	log.debug("Looking up message '" + key 
                        + "' in Struts' MessageResources");
            }
            MessageResources resources = (MessageResources) messages;
            try {
                if (locale != null) {
                    message = resources.getMessage(locale, key);
                } else {
                    message = resources.getMessage(key);
                }
            } catch (Throwable t) {
                message = null;
            }
        } else if (messages != null && messages instanceof ResourceBundle) {
            if (log.isDebugEnabled()) {
                log.debug("Looking up string '" + key + "' in ResourceBundle");
            }
            ResourceBundle bundle = (ResourceBundle) messages;
            try {
            	message = bundle.getString(key);
            } catch (MissingResourceException mre) {
            	message = null;
            }
        } else {
            message = key;
        }

        if (message == null) {
            message = key;
        }

        return message;
    }

	/**
	 * Get the menu's target (if it exists).  This method
	 * is public to expose it to Velocity.
	 * 
	 * @param menu
	 */
	public String getMenuTarget(MenuComponent menu) {
        String menuTarget = target;

        if (this.target != null) {
            menuTarget = target;
        } else {
            if (menu.getTarget() != null) {
                menuTarget = menu.getTarget();
            } else {
                menuTarget = MenuDisplayer._SELF;
            }
        }

        return menuTarget;
    }

	/**
	 * Get the menu's tooltip (if it exists).  This method
	 * is public to expose it to Velocity.
	 * 
	 * @param menu
	 */
	public String getMenuToolTip(MenuComponent menu) {
        String tooltip = EMPTY;

        if (menu.getToolTip() != null) {
            tooltip = this.getMessage(menu.getToolTip());
        } else {
            tooltip = this.getMessage(menu.getTitle());
        }

        return tooltip;
    }

    public abstract void display(MenuComponent menu)
    throws JspException, IOException;
}