初学spring mvc 怎么取不到form的值

aiq 2017-01-11 10:29:22

spring mvc 4.1.6

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="3.0" 

	xmlns="http://java.sun.com/xml/ns/javaee" 

	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 

	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

  <display-name></display-name>	

  <!-- 字符集过滤器  -->  

  <filter>  

      <filter-name>encodingFilter</filter-name>  

      <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  

      <init-param>  

          <param-name>encoding</param-name>  

          <param-value>UTF-8</param-value>  

      </init-param>  

      <init-param>  

          <param-name>forceEncoding</param-name>  

          <param-value>true</param-value>  

      </init-param>  

  </filter>  

  <filter-mapping>  

      <filter-name>encodingFilter</filter-name>  

      <url-pattern>/*</url-pattern>  

  </filter-mapping>    

  <!-- spring MVC的核心就是DispatcherServlet -->   

  <servlet>  

    <servlet-name>springDispatcherServlet</servlet-name>  

    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 

    <init-param>  

      <param-name>contextConfigLocation</param-name>  

      <param-value>/WEB-INF/spring-mvc.xml</param-value>   

    </init-param>  

    <load-on-startup>1</load-on-startup>  

  </servlet>  

  <!-- 设置dispatchservlet的匹配模式，通过把dispatchservlet映射到/，默认servlet会处理所有的请求，包括静态资源  -->  

  <servlet-mapping>  

    <servlet-name>springDispatcherServlet</servlet-name>  

    <url-pattern>/</url-pattern>  

  </servlet-mapping>     

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

</web-app>

spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xmlns:p="http://www.springframework.org/schema/p" 

  xmlns:context="http://www.springframework.org/schema/context"

  xmlns:util="http://www.springframework.org/schema/util"

  xmlns:mvc="http://www.springframework.org/schema/mvc"

  xsi:schemaLocation="

      http://www.springframework.org/schema/beans

      http://www.springframework.org/schema/beans/spring-beans.xsd

      http://www.springframework.org/schema/util

      http://www.springframework.org/schema/util/spring-util.xsd

      http://www.springframework.org/schema/context 

      http://www.springframework.org/schema/context/spring-context.xsd

      http://www.springframework.org/schema/mvc

      http://www.springframework.org/schema/mvc/spring-mvc.xsd" >

 



    <!-- 使用默认的注解映射 --> 

    <mvc:annotation-driven/>



    <!-- 自动扫描controller包中的控制器 -->

    <context:component-scan base-package="com.mvc.rest"/>



    <!-- 视图解析路径配置 -->

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

       <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>    

       <property name="prefix" value="/"/>

       <property name="suffix" value=".jsp"/>

    </bean>   

    

</beans>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>   

    <title>My JSP 'welcome.jsp' starting page</title>    

	<meta http-equiv="pragma" content="no-cache">

	<meta http-equiv="cache-control" content="no-cache">

	<meta http-equiv="expires" content="0">    

	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

	<meta http-equiv="description" content="This is my page">

  </head>

  

  <body>

    <form action="login" method="post">  

        <label>username:</label><input type="text" name="username" /><br>  

        <label>password:</label><input type="text" name="password" /><br>  

        <input type="submit" value="submit" />  

    </form>  

  </body>

</html>

package com.mvc.rest;



import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

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.servlet.ModelAndView;



@Controller

public class RestConstroller {

	

    public RestConstroller() {}

    @RequestMapping(value ="/login", method = RequestMethod.GET)  

    public ModelAndView regist( String username,String password){  

        System.out.println(username);

        if("admin".equals(username)){  

            return new ModelAndView("success");  

        }  

        return new ModelAndView("fail");  

    }  



}

System.out.println(username);这个地方运行后为null；那个地方有问题，还是配置文件漏了什么？

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aiq 2017-01-11

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我改成POST，也重新发布了出现 type Status report message Request method 'GET' not supported description The specified HTTP method is not allowed for the requested resource. 是不是那个地方配置有问题

尼古拉斯-全蛋 2017-01-11

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试了一下，后台改成post可以收到数据。你把你的重新发布一下试试

aiq 2017-01-11

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去掉method，变成 @RequestMapping(value ="/login") 也没有，是null 那怎么改呢，查了，改了好几个地方还是不行

___d 2017-01-11

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前台用post. 后台用get 你不觉得有问题吗？

aiq 2017-01-11

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怎么改？改method = RequestMethod.POST 页面报 type Status report message Request method 'GET' not supported description The specified HTTP method is not allowed for the requested resource. 去掉method，变成 @RequestMapping(value ="/login") 也是这个错误

那年花 2017-01-11

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你页面写的method要与你controller里面的metho一致一起get或者一起post

ichavin 2017-01-11

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应该是get是没错的，但是我记得以前我写的时候，出现这种情况会报错或者404，

尼古拉斯-全蛋 2017-01-11

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xiesisi3 2017-01-11

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你页面写的POST Controller里面用的GET 怎么拿得到参数。。。

aiq 2017-01-11

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重新建了个项目又好了，晕死了

aiq 2017-01-11

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我把form action="login" 里的login改成其他名字的，只要不是login即可以了，比如login_sys，java里也对应login_sys，post和get就后了，什么问题？我已经删除，重新部署了，搞不明白

dominicHa 2017-01-11

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不写method应该是不报错的吧

aiq 2017-01-11

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前台get，后台也get，或不写method，可以取到数据；前台post，后台改post，值为null 不写method，出现错误 type Status report message Request method 'GET' not supported description The specified HTTP method is not allowed for the requested resource.