Just give the individual button elements a unique name. When pressed, the button’s name is available as a request parameter the usual way like as with input elements.
You only need to make sure that the button inputs have type="submit" as in <input type="submit"> and <button type="submit"> and not type="button", which only renders a “dead” button purely for onclick stuff and all.
E.g.
<form action="${pageContext.request.contextPath}/myservlet" method="post">
<input type="submit" name="button1" value="Button 1" />
<input type="submit" name="button2" value="Button 2" />
<input type="submit" name="button3" value="Button 3" />
</form>
with
@WebServlet("/myservlet")
public class MyServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
MyClass myClass = new MyClass();
if (request.getParameter("button1") != null) {
myClass.method1();
} else if (request.getParameter("button2") != null) {
myClass.method2();
} else if (request.getParameter("button3") != null) {
myClass.method3();
} else {
// ???
}
request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);
}
}
Alternatively, use <button type="submit"> instead of <input type="submit">, then you can give them all the same name, but an unique value. The value of the <button> won’t be used as label, you can just specify that yourself as child.
E.g.
<form action="${pageContext.request.contextPath}/myservlet" method="post">
<button type="submit" name="button" value="button1">Button 1</button>
<button type="submit" name="button" value="button2">Button 2</button>
<button type="submit" name="button" value="button3">Button 3</button>
</form>
with
@WebServlet("/myservlet")
public class MyServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
MyClass myClass = new MyClass();
String button = request.getParameter("button");
if ("button1".equals(button)) {
myClass.method1();
} else if ("button2".equals(button)) {
myClass.method2();
} else if ("button3".equals(button)) {
myClass.method3();
} else {
// ???
}
request.getRequestDispatcher("/WEB-INF/some-result.jsp").forward(request, response);
}
}