spring - 两个具有相同 URL 但不同参数的 @GetMapping

Question

我正在学习 Spring MVC，但在这个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:

引起:java.lang.IllegalStateException:不明确的映射。无法映射“demoController”方法academy.learnprogramming.controller.DemoController#welcome92(字符串，整数，模型)到 {GET [/welcomeWithParam]}: 已经有 'demoController' bean 方法academy.learnprogramming.controller.DemoController#welcome91(String, Model) 映射。

那么，Spring 告诉我我们不能有两个具有相同 URL 但参数数量/类型不同的 GET 映射？

如果我更改其中一个 @GetMapping("") 值的值，它可以正常工作。

Answer 1

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) {
  // ...
}