To create a multi-action controller in the Spring 5.0 platform, follow these steps:
- Let us start this recipe with a multi-action controller named MultiActionController with all its handler methods mapped to their respective URLs, similar to a hub of independent services:
@Controller
public class MultiActionController {
@RequestMapping(value={"/send/*", "/list/*"},
method=RequestMethod.GET)
public String defaultMethod(){
return "default_msg";
}
@RequestMapping(value="/send/message_get.html",
method=RequestMethod.GET)
public String sendGetMessage(Model model){
String message = "Multi-action GET URL Mapping";
model.addAttribute("message", message);
return "get_msg";
}
@RequestMapping(value="/send/message_post.html",
method=RequestMethod.POST)
public String sendPostMessage(Model model){
String message = "Multi-action Post URL Mapping";
model.addAttribute("message", message);
return "post_msg";
}
@RequestMapping(value="/list/multilist.html",
method=RequestMethod.GET)
public String viewTransactions(){
return "multi_list";
}
}
- The preceding three handler methods are typical request transactions mapped to their respective URL and HTTP methods. The handler defaultMethod() is quite unique because its action will be triggered whenever a request URL that starts with a context path /send or /list has been executed but happens to be non-existent. This method serves as the callback feature of the multi-action controller whenever the URL invoked does not exist.
- Next, create the simple views default_msg, get_msg and post_msg, all having their own set of message bundle labels and JSTL tags for rendering.
- Moreover, create a multi_list page that will serve as a facade for GET and POST transactions:
<%@ taglib prefix="spring"
uri="http://www.springframework.org/tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<title><spring:message code="multi_facade" /></title>
</head>
<body>
<a href="/ch03/send/message_get.html">GET Transaction</a>
<br/>
<form action="/ch03/send/message_post.html" method="post" >
<input type="submit" value="POST Transaction" />
</form>
</body>
</html>
- Update both views.properties and messages_en_US.properties for the changes in the view configuration and resource bundle messages, respectively.
- Then clean, build, and deploy the project. Call each request handler independently.