How do I call a specific Java method on a click/submit event of a specific button in JSP?
jsp, servlets
Solution
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);
}
}
See also:
- Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"
- How do I pass current item to Java method by clicking a hyperlink or button in JSP page?
Problem
My Java file is: ``` public class MyClass { public void method1() { // some code } public void method2() { //some code } public void method3() { //some code } } ``` In my JSP page I have three HTML buttons. If I click on `button1`, then only `method1` will be called, if I click on `button2` then only `method2` will execute, and if `button3`, then only `method3`, and so on. How can I achieve this?