Spring MVC How take the parameter value of a GET HTTP Request in my controller method?

In this period I am studing the Spring MVC showcase example (downloadable from STS dasboard) and I have some simple question about the Request Mapping examples:

1. In my home.jsp page I have this link:

    	<li>
    		<a id="byParameter" class="textLink" href="<c:url value="/mapping/parameter?foo=bar" />">By path, method, and presence of parameter</a>
    	</li>
   

As you can see by this link I am doing an HTTP GET Request having a "foo" parameter containing the value: "bar".

This HTTP Request is handled by the following method of the controller class MappingController:

@RequestMapping(value="/mapping/parameter", method=RequestMethod.GET, params="foo")
public @ResponseBody String byParameter() {
	return "Mapped by path + method + presence of query parameter! (MappingController)";
}

This method manage HTTP Request (only GET type) that have a parameter named "foo"

How can I take the value ("bar") of this parameter and put it in a variable inside the code of my by Parameter method?

As explained in the documentation, by using an @RequestParam annotation:

public @ResponseBody String byParameter(@RequestParam("foo") String foo) {
    return "Mapped by path + method + presence of query parameter! (MappingController) - foo = "
           + foo;
}

You could also use a URI template. If you structured your request into a restful URL Spring could parse the provided value from the url.

HTML

<li>
    <a id="byParameter" 
       class="textLink" href="<c:url value="/mapping/parameter/bar />">By path, method,and
           presence of parameter</a>
</li>

Controller

@RequestMapping(value="/mapping/parameter/{foo}", method=RequestMethod.GET)
public @ResponseBody String byParameter(@PathVariable String foo) {
    //Perform logic with foo
    return "Mapped by path + method + presence of query parameter! (MappingController)";
}

Spring URI Template Documentation