Struts 1 - How to display ActionMessages

Question

I am displaying ActionMessages through a JSP file by the following command:

<logic:messagesPresent message="true">
    <ul id="messsages">
        <html:messages id="msg" message="true">
            <li><bean:write name="msg"/> </li>
        </html:messages>
    </ul>
</logic:messagesPresent>

Now I want to display only selected messages. How can I indicate which message to display?

Updated

Actually I have two ActionMessages object - messages and warnings. Now I want to display both of them on separate JSP page... One page to show messages and other for warnings.

So how to indicate in the JSP page that which messages to display?

Updated - 2

Now, I found a strange thing.

saveMessages(request, messages);
saveMessages(request, warnings);

When I wrote the above code, only warnings was working. When I reversed the order of the above two statements, then only messages was working.

It seems that we can add only one ActionMessages object in a request. If it is correct, then how to display messages in two ActionMessages objects seperately.

Answer 1

Simple,

Separate your messages and your warnings: In your struts action, save your messages and warnings as follows:

//For messages
saveMessages(request, messages);

//For warnings
saveErrors(request, warnings);

To display them:

<logic:messagesPresent message="true">
    <html:messages id="aMsg" message="true">
        <logic:present name="aMsg">
            <!-- Messages -->
            <div class="messages">
                <bean:write name="aMsg" filter="false" />
            </div>
        </logic:present>
    </html:messages>
</logic:messagesPresent>

<logic:messagesPresent message="false">
    <html:messages id="aMsg" message="false">
        <logic:present name="aMsg">
            <!-- Warnings-->
            <div class="warnings">
                <bean:write name="aMsg" filter="false" />
            </div>
        </logic:present>
    </html:messages>
</logic:messagesPresent>

This displays all messages (by setting message="true")

<html:messages id="aMsg" message="true">

This displays all warnings (by setting message="false")

<html:messages id="aMsg" message="false">

UPDATE Seeing that you're now clearing your question, the simplest way would be to do this.

Have a certain flag that will indicate whether the user would like to view messages or warnings. On the Struts Action, request the flag and check if the user selected viewing messages or warnings. You then save either warnings or messages based on the user selection and display the same page (as you wrote above) to display messages.

The reason is this, Struts (when storing you messages or errors) stores it on request or session with the following constant.

• Globals.MESSAGE_KEY (that is assigned when you do saveMessages(request, messages))
• Globals.ERROR_KEY (that is assigned when you do saveErrors(request, errors))

when using <logic:messagesPresent message="true">, Struts searches for the MESSAGE_KEY (if message=true) or ERROR_KEY (if message=false) or both (if message=none). You have no control of that.

<html:messages /> TLD comments states:

By default the tag will retrieve the bean it will iterate over from the Globals.ERROR_KEY constant string,
but if this attribute is set to 'true' the bean will be retrieved from the Globals.MESSAGE_KEY constant string. Also if this is set to 'true', any value assigned to the name attribute will be ignored.

You can also write scriptlet to check if those keys exists, then <logic:iterate /> through the key to display the messages (but that'll be too much work).

Hope this helps.