How can I tell which submit button was clicked

Question

I have several different submit buttons on my JSP in one form tag that all point to the same servlet. I need to know which submit button was clicked. How can I find out which button was clicked?

Solution 1

if request.getParameter("button-name") is not null then this is the button that was pressed

Solution 2

Each Submit button should have a different name:

<input type="submit" value="This is a submit button" name="submit1">
<input type="submit" value="Another submit button" name="submit2">
<input type="submit" value="Yet another submit button!" name="submit3">

Then, the name of the input should appear in the parameters sent to wherever the form is posting to, something like

post.jsp?key=value&submit3=&....

http://www.w3schools.com/tags/tag_input.asp

Solution 3

This is kind of similar to the DispatchAction in Struts. What they do is to have a hidden field, and when you submit the form, have onClick() set the value to specify which action is taken.

<input type="hidden" name="dispatchAction"/>
<input type="submit" value="Edit"   onClick="setDispatchAction('edit')">
<input type="submit" value="Delete" onClick="setDispatchAction('delete')">

Comments

[Muhammad Ahmad Afzal]

are they <button> tags or <input type="submit"> ?

[mkoryak]

do you care about this in the controller on in javascript?

[Muhammad Ahmad Afzal]

well IE6 sends a value for all the <button> tags, whether clicked or not

[crauscher]

No, it does not appear in the query string.

[BalusC]

Warning: MSIE sends the button's body "some text" or "some other text" as parameter value, not the value attribute! You should not give all buttons the same name, but a different name and intercept on the presence of the button name only. I.e. if it is not null, then it is pressed, else if it is null, then it is not pressed.