How are Spring MVC Controllers being bound to JSP pages? - spring

Question

Hi I am new to spring and I am trying to develop a simple portlet that accepts users first and last name and saves it to db using hibernate.
Basically I cannot figure out how the jsps and controllers communicate; I am missing some chunk here.
This is my first controller that needs to be called (where do I mention so?)
package codes.controller;
import javax.portlet.RenderResponse;
import codes.base.User;
import codes.service.UserService;
#Controller(value="SimpleUserController")
#RequestMapping(value = "VIEW")
public class SimpleUserController {
// -- auto-wiring of service dependency
#Autowired
#Qualifier("userService")
private UserService userService;
// --maps the incoming portlet request to this method
#RenderMapping
public String showUsers(RenderResponse response) {
return "home";
}
#ExceptionHandler({ Exception.class })
public String handleException() {
return "errorPage";
}
// -- #ModelAttribute here works as the referenceData method
#ModelAttribute(value="user")
public User getCommandObject() {
return new User();
}
}
Initially I am displaying a home.jsp that will display the form with two input boxes and a submit button.
<%#include file="include.jsp" %>
<portlet:actionURL var="addUserActionUrl">
<portlet:param name="myaction" value="addUser" />
</portlet:actionURL>
<form:form name="home" commandName="user" method="post"
action="${addUserActionUrl}">
<table>
<tr>
<td>First Name:<font style="color: #C11B17;">*</font></td>
<td><form:input path="firstname" /></td>
</tr>
<tr>
<td>Last Name:<font style="color: #C11B17;">*</font></td>
<td><form:input path="lastname" /></td>
</tr>
<table align="right">
<tr>
<td> </td>
<td><input type="submit" value="SUBMIT" /></td>
</tr>
</table>
</table>
</form:form>
This JSP should call the action method in the AddUserController.java:
package codes.controller;
import javax.portlet.ActionResponse;
import javax.portlet.RenderResponse;
import codes.base.User;
import codes.service.UserService;
#Controller(value = "AddUserController")
#RequestMapping(value = "VIEW")
public class AddUserController {
#Autowired
#Qualifier("userService")
private UserService userService;
#RenderMapping(params = "myaction=addUser")
public String showRegisterPage(Model model) {
model.addAttribute("user", new User());
model.addAttribute("users", getUsers());
return "addUser";
}
public List<User> getUsers() {
return userService.getAllUsers();
}
#ActionMapping(params = "myaction=addUser")
public void addBook(#ModelAttribute(value = "user") User user,
BindingResult bindingResult, ActionResponse response,
SessionStatus sessionStatus) {
if (!bindingResult.hasErrors()) {
userService.addUser(user);
response.setRenderParameter("myaction", "users");
sessionStatus.setComplete();
} else {
response.setRenderParameter("myaction", "addUser");
}
}
}
This time this firstname+last name should be saved in the db AND the screen should refresh to show a new form that will have a dropdown with the current users' names in the database and another first name and last name form fields. If you select a username from the dropdown the form fields are populated and you can edit these values and click on UPdate button to save the values in DB. Otherwise you can add a new user to the database using submit button.
addUser.jsp:
<%#include file="include.jsp" %>
<portlet:actionURL var="addUserActionUrl">
<portlet:param name="myaction" value="addUser" />
</portlet:actionURL>
<portlet:renderURL var="homeUrl">
<portlet:param name="myaction" value="Users" />
</portlet:renderURL>
<script type="text/javascript" src="js/userRelated.js"></script>
<form:form name="addUser" commandName="user" method="post"
action="${addUserActionUrl}">
<form:select path="model">
<form:option value="NONE" label="--- Select ---" id="userList" onchange="showHide()"/>
<form:options items="${users}" />
</form:select>
<table>
<tr>
<td>First Name:<font style="color: #C11B17;">*</font></td>
<td><form:input path="firstname" /></td>
</tr>
<tr>
<td>Last Name:<font style="color: #C11B17;">*</font></td>
<td><form:input path="lastname" /></td>
</tr>
<table align="right">
<tr>
<td> </td>
<td><input type="submit" id="submit" value="SUBMIT" />SUBMIT</td>
</tr>
<tr>
<td> </td>
<td><input type="submit" id="update" value="SUBMIT" />UPDATE</td>
</tr>
</table>
</table>
</form:form>
I am hiding and unhiding the SUBMIT/UPDATE button using onchange of dropdown. How do I call different functions in the addUsercontroller depending on the button available?

Answer 1

by updating the action attribute of form element with javascript