msg.java

非常简便可以在jsp页面上弹出或显示提示信息的工具类!

/**
 * 
 */
package com.dotease.common;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts.Globals;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.util.MessageResources;
import java.util.ArrayList;
/**
 * @author Administrator牛一Niuyi  2007-10-9
 *2007-10-9
 */
public class Msg {

	/**
	 * save the error messages! This like Action.saveErrors(); 
	 * @param request
	 * @param errors
	 */
	protected  static final void saveErrors(HttpServletRequest request,ActionMessages errors) {

        if ((errors == null) || errors.isEmpty()) {
            request.removeAttribute(Globals.ERROR_KEY);
            return;
        }
        // Save the error messages we need
        request.setAttribute(Globals.ERROR_KEY, errors);
        
	}
	
	/**
	 * 保存弹出消息到Request,使用默认的key:showError 
	 * 此信息在前台设置<html:errors property="showError"/>后，弹出!
	 * 建议:<html:errors>放在紧挨着</body>的地方！
	 * 适合有错误，就返回！ 如果多次调用，会覆盖上次的Errors
	 * @param request  
	 * @param ActionMessage    
	 * 
	 */
public static final void saveError(HttpServletRequest request,ActionMessage error) {
		
		MessageResources msgResource = ((MessageResources) request.getAttribute(Globals.MESSAGES_KEY));
		String msg=msgResource.getMessage(error.getKey());
		int length=0;
		if(error.getValues()!=null)
			length=error.getValues().length;
		for(int i=0;i<length;i++)
		{
			msg=msg.replace("{"+i+"}", error.getValues()[i].toString());
			
		}
		ActionMessages errors = new ActionMessages();
		errors.add("showError",new ActionMessage("showError",msg));
		saveErrors(request,errors);	
	}

	/**
	 * 把ActionMessage对象转化为文本字符串
	 * @param request
	 * @param msg
	 * @return
	 */
public static final String msgToString(HttpServletRequest request,ActionMessage error) 
{
	MessageResources msgResource = ((MessageResources) request.getAttribute(Globals.MESSAGES_KEY));
	String msg=msgResource.getMessage(error.getKey());
	msg=filterString(msg);
	int length=0;
	if(error.getValues()!=null)
		length=error.getValues().length;
	for(int i=0;i<length;i++)
	{
		msg=msg.replace("{"+i+"}", error.getValues()[i].toString());
		
	}
	return msg;
}
	/**
	 * 返回MessageResources对象，通过它可以获得配置资源
	 * @param request
	 * @return
	 */
public static final MessageResources getMsgResources(HttpServletRequest request) 
{	
	return ((MessageResources) request.getAttribute(Globals.MESSAGES_KEY));	
}



public static final ActionMessages getErrors(HttpServletRequest request)
{
	ActionMessages errors = (ActionMessages)request.getAttribute(Globals.ERROR_KEY);
    if(errors == null)
    	errors = new ActionMessages();
    return errors;
	
}
	/**
	 * 保存弹出消息到Request,使用默认的key:showError 
	 * @param request
	 * @param error
	 */
public static final void addError(HttpServletRequest request,ActionMessage error)
{
	ActionMessages errors=getErrors(request);
	errors.add("showError", new ActionMessage("showError",msgToString(request,error)));
	saveErrors(request,errors);
}
public static final void addErrorToken(HttpServletRequest request)
{
	ActionMessages errors=getErrors(request);
	errors.add("showError", new ActionMessage("error.token"));
	saveErrors(request,errors);
}
	/**
	 * 保存弹出消息到Request,使用默认的key:showError 
	 * @param request
	 * @param key
	 */
public static final void addError(HttpServletRequest request,String key)
{
	ActionMessages errors=getErrors(request);
	String temp=key;
	temp=getMsgResources(request).getMessage(key);
	if(temp!=null)
		key=temp;
	errors.add("showError", new ActionMessage("showError",key));
	saveErrors(request,errors);
}
public static final void addMsg(HttpServletRequest request,String key,ActionMessage error)
{
	ActionMessages errors=getErrors(request);
	errors.add(key, error);
	saveErrors(request,errors);
}
public static final void addMsg(HttpServletRequest request,String key,String  value)
{
	ActionMessages errors=getErrors(request);
	errors.add(key, new ActionMessage("showMsg",value));
	saveErrors(request,errors);
}
public static final String filterString(String s)
{
	if(s.indexOf("<")==-1)
		return s;
	int len=s.length();
	int ps=s.indexOf("<");
	int pe=s.indexOf(">");
	s=s.substring(0, ps)+s.substring(pe+1,s.length());
	return filterString(s);	
}
//error.DBError
public static final void addError(HttpServletRequest request,Exception e)
{
	ActionMessages errors=getErrors(request);
	String temp=getMsgResources(request).getMessage("error.exception");
	errors.add("showError", new ActionMessage("showError",temp+e.getMessage()));
	saveErrors(request,errors);
	e.printStackTrace();
}

}