Using the @PathVariable annotation in Spring MVC 3.0

Let’s say that you are creating an user account-based web application in Spring 3.0.  You would like to create a controller that would allow users to see each other’s profile by using a URL such as http://mysite/profile/username.  For example:

http://mysite/profile/Adam  would show user Adam’s profile.

http://mysite/profile/Baker would show user Baker’s profile.

Spring 3.0’s annotated controllers make this kind of mapping easy with the new @PathVariable mapping.

package com.technologicaloddity.hellowebapp;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class ShowProfileController {

    @RequestMapping("/profile/{username}")
    public String showProfile(Model model, @PathVariable("username") String username) {
        model.addAttribute("username", username);
        return "showProfile"; // the view name
    }
    
}

As you can see, the RequestMapping for the showProfile method has something a bit unusual: {username}.  This is a PathVariable, and it means that this method will serve any request of the format "/profile/someUserName".  We capture the actual username in the next line using the @PathVariable annotation, and store it in the String username.  Now we can use it however we want!

6 thoughts on “Using the @PathVariable annotation in Spring MVC 3.0”

  1. Also as you will see further below, with the MVC Java config it is easier to see the underlying configuration as well as to make fine-grained customizations directly to the created Spring MVC beans.

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