如何在MVC中重载控制器方法？

@Controller
@RequestMapping("/example")
public class ExampleController {

    @RequestMapping(value = "/index", method = RequestMethod.GET)
    public String index() {
        // 执行默认的逻辑
        return "index";
    }

    @RequestMapping(value = "/index", method = RequestMethod.POST)
    public String index(@RequestParam("param") String param) {
        // 根据请求参数执行不同的逻辑
        if (param.equals("A")) {
            // 执行逻辑 A
            return "viewA";
        } else if (param.equals("B")) {
            // 执行逻辑 B
            return "viewB";
        } else {
            // 执行默认的逻辑
            return "index";
        }
    }
}