Sup*_*net 4 java jsp spring-mvc
我正在尝试制作一个简单的Spring MVC应用程序.
这是我的 HelloController
package com.springapp.mvc;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
@RequestMapping("/")
public class HelloController {
@RequestMapping(method = RequestMethod.GET)
public String printWelcome(ModelMap model,@RequestParam(value = "xx",required
=true)String xx) {
model.addAttribute("message", "Hello Mahdi");
return "hello";
}
}
和JSP文件:
<html>
<body>
<h1>${message}</h1>
<form action="/" method="GET">
<input type="text" name="xx">
<button type="submit">submit</button>
</form>
</body>
</html>
我尝试运行该应用程序时收到以下错误:
HTTP Status 400 - Required String parameter 'xx' is not present
我是Spring MVC的新手,请帮忙.
您的用例需要两个操作:
<form><form>这应该映射到两个处理程序方法
@RequestMapping(method = RequestMethod.GET)
public String getForm() {
model.addAttribute("message", "Hello Mahdi");
return "hello"; // assume hello.jsp
}
@RequestMapping(params={"submit"}, method = RequestMethod.GET)
public String printWelcome(ModelMap model, @RequestParam(value = "xx",required=true) String xx) {
/*
Do something with submitted parameter
and return some view name
*/
}
如果要访问表单,请进行GET /.提交表单时,您也可以执行GET /,但是您需要其他东西来区分请求.在这里,我用过params="submit".因此,您需要将提交输入更改为
<input type="submit" name="submit">submit</button>
或者只是放置你已经使用过的参数(params={"xx"}).