Getting error message using JavaBean

[Sunder Ganapathy]

The relevant Bean code is as follows where errors is a hashtable.

	public String getErrorMsg(String msg)
	{
		errorMsg =(String)errors.get(msg.trim());
		return (errorMsg == null) ? "":errorMsg;
	}

If I use

 <%=handler.getErrorMsg("username")%>   

it returns the error message correctly.

If I change it to

  <c:out value='${handler.errorMsg["username"]}'/>  

I get the following error.
:javax.el.PropertyNotFoundException: Property 'errorMsg' not found on type com.Login

How to overcome this problem.

[Sebastian Janisch]

EL strictly follows the JavaBean standard.
JavaBean Getters do not have arguments. And you cannot pass argument to EL.

If your bean property would look like this

 public String getErrors() { ... } 

then $handler.errors would return the property.

[Bear Bibeault]

If you create a "getter" that returns the map, it's easy to address maps:

${myBean.myMap[key]}    

[Bear Bibeault]

Remember, the EL wasn't introduced just to be a one-to-one replacement for Java code in a JSP -- that would have been senseless.

Rather, the EL is specifically designed to help you do the things that you should be doing in JSP pages, and to prevent you from doing what you shouldn't.

It requires a little bit of a change in thinking. This is a good example of that. You don't want to expose general methods, but rather bean getters. And by having a getter that exposes a map, you can key into that map with ease.

[Bear Bibeault]

so in your example, your bean would change as follows:

public Map<String,String> getErrors() { return this.errors; }    

Then in your JSP:

<c:out value='${handler.errors.username}'/>     

How easy is that?!

[hexin orsen]

i think that is not preciseness:
public String getErrorMsg(String msg)
{
errorMsg =(String)errors.get(msg.trim());
return (errorMsg == null) ? "":errorMsg;
}
if parameter of getErrorMsg is null,there is NullPointerException that you using msg.trim() .if you are not sure msg is not null,so your code shoud change .

[Sunder Ganapathy]

Thanks a lot for all the feedback.

[Sunder Ganapathy]

Thanks a lot Bear. You mentioned "It requires a little bit of a change in thinking.".
You helped me to achieve. Thanks a lot once again.