两个具有相同 URL 但参数不同的 @GetMapping

Two @GetMapping with same URL but different parameters

我正在学习 Spring MVC,但在学习过程中我遇到了这个问题:

    // http://localhost:8080/todo-list/welcomeWithParam?user=Stefan
    @GetMapping("welcomeWithParam")
    public String welcome91(@RequestParam String user, Model model) {
        model.addAttribute("helloThroughParam", demoService.getHelloMessage(user));
        return "welcome-with-model";
    }

    // http://localhost:8080/todo-list/welcomeWithParam?user=Stefan&age=31
    @GetMapping("welcomeWithParam")
    public String welcome92(@RequestParam String user, @RequestParam int age, Model model) {
        model.addAttribute("helloThroughParam", demoService.getHelloMessage(user));
        model.addAttribute("age", age);
        return "welcome-with-model";
    }

我收到这个错误:

原因:java.lang.IllegalStateException:映射不明确。无法映射 'demoController' 方法 academy.learnprogramming.controller.DemoController#welcome92(字符串、整数、模型) to {GET [/welcomeWithParam]}: 已经有'demoController'个bean方法 academy.learnprogramming.controller.DemoController#welcome91(String, Model) 已映射。

所以,Spring 告诉我我们不能有两个具有相同 URL 但不同 number/type 参数的 GET 映射?

如果我更改其中一个 @GetMapping("") 值的值,它工作正常。

像这样:

@RequestMapping(value = "/welcomeWithParam", params = "user")
public String welcome91(@RequestParam String user, Model model) {
  // ...
}

@RequestMapping(value = "/welcomeWithParam", params = {"user","age"})
public ModelAndView welcome92(@RequestParam String user, @RequestParam int age, Model model) {
  // ...
}