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Spring向页面传值和接受页面传过来的参数详解

时间：2020-10-16 02:59 编辑：来源：阅读：
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摘要：Spring向页面传值和接受页面传过来的参数详解

本文主要给大家介绍了关于Spring向页面传值和接受页面传过来的参数的相关内容，分享出来供大家参考学习，下面来一起看看详细的介绍： [b]一、从页面接收参数[/b] [b]spring MVC接收请求提交的参数值的几种方法：[/b] 1、使用HttpServletRequest获取。

 @RequestMapping("/login.do") 
public String login(HttpServletRequest request){ 
 String name = request.getParameter("name") 
 String pass = request.getParameter("pass") 
}

2、使用@RequestParam注解。

 @RequestMapping("/login.do") 
 public String login(HttpServletRequest request, 
  String name, 
 @RequestParam("pass")String password) // 表单属性是pass,用变量password接收 
 { 
 syso(name); 
 syso(password) 
 }

3、使用自动机制封装成实体参数。

 <form action="login.do"> 
 用户名：<input name="name"/> 
 密码：<input name="pass"/> 
 <input type="submit" value="登陆"> 
 </form> 
 
 //封装的User类 
 public class User{ 
 private String name; 
 private String pass; 
 }

 @RequestMapping("/login.do") 
 public String login(User user) 
 { 
 syso(user.getName()); 
 syso(user.getPass()); 
 }

[b]二、向页面传值[/b] 当Controller组件处理后，需要向响应JSP传值时，可以使用的方法: 1)，使用HttpServletRequest 和 Session 然后[code]setAttribute()[/code] ，就和Servlet中一样 Model数据会利用HttpServletRequest的Attribute传值到success.jsp中

 @RequestMapping("/login.do") 
 public ModelAndView login(String name,String pass){ 
 User user = userService.login(name,pwd); 
 Map<String,Object> data = new HashMap<String,Object>(); 
 data.put("user",user); 
 return new ModelAndView("success",data); 
 }

2)，使用ModelAndView对象 3)，使用ModelMap对象使用ModelMap参数对象示例: ModelMap数据会利用HttpServletRequest的Attribute传值到success.jsp中

 @RequestMapping("/login.do") 
 public　String login(String name,String pass ,ModelMap model){ 
 User user = userService.login(name,pwd); 
 model.addAttribute("user",user); 
 model.put("name",name); 
 return "success"; 
 }

4)，使用@ModelAttribute注解使用@ModelAttribute示例在Controller方法的参数部分或Bean属性方法上使用@ModelAttribute数据会利用HttpServletRequest的Attribute传值到success.jsp中

 @RequestMapping("/login.do") 
 public String login(@ModelAttribute("user") User user){ 
 //TODO 
 return "success"; 
 } 
 
 @ModelAttribute("name") 
 public String getName(){ 
 return name; 
 }

5）Session存储：可以利用HttpServletReequest的[code]getSession()[/code]方法

 @RequestMapping("/login.do") 
 public String login(String name,String pwd 
 ModelMap model,HttpServletRequest request){ 
 User user = serService.login(name,pwd); 
 HttpSession session = request.getSession(); 
 session.setAttribute("user",user); 
 model.addAttribute("user",user); 
 return "success"; 
 }

6）自定义Map

@ResponseBody
 @RequestMapping(value = "/updatestatus", method = RequestMethod.POST)
 public Map<String, Object> updateStatus(HttpServletRequest request) {
 Map<String, Object> result = new HashMap<String, Object>();
 String id = request.getParameter("id");
 SystemAdministrator sysadmin=systemAdminBiz.get(Integer.valueOf(id));
 sysadmin.setStatus(1);
 boolean flag = systemAdminBiz.update(sysadmin);
 result.put("status", flag);
 return result;
 }

@RequestMapping(value = "/list", method = {RequestMethod.POST,RequestMethod.GET})
 public String queryAdministrator(HttpServletRequest request,ModelMap model) {
 Integer roleId = request.getParameter("roleListById") == null ? 0 : Integer.parseInt(request.getParameter("roleListById"));
 Map<String, Object> properties = new HashMap<String, Object>();
 if(roleId.intValue() > 0) {
 properties.put("role:=", roleId);
 model.put("roleId", roleId);
 }
 List<SystemAdministrator> administrator = systemAdminBiz.find(properties);
 List<SystemRole> systemRole = systemRoleBiz.getAll();
 model.put("administratorList", administrator);
 model.put("roleList", systemRole);
 return "sys_admin_list";
 }

7）Spring MVC 默认采用的是转发来定位视图，如果要使用重定向，可以如下操作 1，使用RedirectView 2，使用redirect:前缀

 public ModelAndView login(){ 
 RedirectView view = new RedirectView("regirst.do"); 
 return new ModelAndView(view); 
 }

或者用如下方法，工作中常用的方法：

 public String login(){ 
 //TODO 
 return "redirect:regirst.do"; 
}

[b]三、实例讲解：[/b] 步骤一：创建新Web项目，导入Spring MVC包和业务层UserService 1. 创建Web项目导入相关的jar包： [img]http://files.jb51.net/file_images/article/201706/201767115450668.png?201757115459[/img] 2. 导入前述业务层UserService类以及依赖的类，等。 User类代码如下：

package com.souvc.entity;

import java.io.Serializable;

public class User implements Serializable {
 private static final long serialVersionUID = -603439325380668432L;
 private int id;
 private String name;
 private String pwd;
 private String phone;

 public User() {
 }

 public User(int id, String name, String pwd, String phone) {
 this.id = id;
 this.name = name;
 this.pwd = pwd;
 this.phone = phone;
 }

 public User(String name, String pwd, String phone) {
 super();
 this.name = name;
 this.pwd = pwd;
 this.phone = phone;
 }

 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }

 public String getPwd() {
 return pwd;
 }

 public void setPwd(String pwd) {
 this.pwd = pwd;
 }

 public String getPhone() {
 return phone;
 }

 public void setPhone(String phone) {
 this.phone = phone;
 }

 @Override
 public int hashCode() {
 return id;
 }

 @Override
 public boolean equals(Object obj) {
 if (this == obj)
 return true;
 if (obj == null)
 return false;
 if (obj instanceof User) {
 User o = (User) obj;
 return this.id == o.id;
 }
 return true;
 }

 @Override
 public String toString() {
 return id + "," + name + "," + pwd + "," + phone;
 }
}

UserDao接口代码如下：

package com.souvc.dao;

import com.souvc.entity.User;

/**
 * 用户数据访问对象接口
 */
public interface UserDao {
 /** 根据唯一用户名查询系统用户, 如果没有找到用户信息返回null */
 public User findByName(String name);
 // public User add(String name, String pwd, String phone);
 // public User find(int id);
 // public User delete(int id);
 // public void update(User user);
}

UserService类代码如下：

package com.souvc.service;

import java.io.Serializable;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.souvc.dao.UserDao;
import com.souvc.entity.User;

/** 业务层 注解 */
@Service
// 默认的Bean ID是 userService
public class UserService implements Serializable {
 private static final long serialVersionUID = 7360372166489952236L;
 private UserDao userDao;

 // @Resource //自动匹配userDao对象并注入
 @Resource(name = "userDao")
 public void setUserDao(UserDao userDao) {
 this.userDao = userDao;//
 }

 public UserDao getUserDao() {
 return userDao;
 }

 /** 登录系统功能 */
 public User login(String name, String pwd) throws NameOrPwdException,
 NullParamException {
 if (name == null || name.equals("") || pwd == null || pwd.equals("")) {
 throw new NullParamException("登录参数不能为空！");
 }
 User user = userDao.findByName(name);
 if (user != null && pwd.equals(user.getPwd())) {
 return user;
 }
 throw new NameOrPwdException("用户名或者密码错误");
 }
}

NameOrPwdException类代码如下：

package com.souvc.service;

/** 用户名或者密码错误 */
public class NameOrPwdException extends Exception {
 public NameOrPwdException() {
 }

 public NameOrPwdException(String message) {
 super(message);
 }

 public NameOrPwdException(Throwable cause) {
 super(cause);
 }

 public NameOrPwdException(String message, Throwable cause) {
 super(message, cause);
 }
}

NullParamException类代码如下：

package com.souvc.service;

/** 参数为空 */
public class NullParamException extends Exception {
 public NullParamException() {
 }

 public NullParamException(String message) {
 super(message);
 }

 public NullParamException(Throwable cause) {
 super(cause);
 }

 public NullParamException(String message, Throwable cause) {
 super(message, cause);
 }
}

JdbcDataSource类代码如下：

package com.souvc.dao;

import java.io.Serializable;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

/** 组件注解 */
@Component
public class JdbcDataSource implements Serializable {

 private static final long serialVersionUID = -8925981939329398101L;

 private String driver;

 @Value("#{jdbcProps.url}")
 private String url;

 @Value("#{jdbcProps.user}")
 private String user;

 @Value("#{jdbcProps.pwd}")
 private String pwd;

 public String getDriver() {
 return driver;
 }

 /** 必须使用Bean属性输入, 否则不能进行JDBC Driver注册 */
 @Value("#{jdbcProps.driver}")
 public void setDriver(String driver) {
 try {
 // 注册数据库驱动
 Class.forName(driver);
 this.driver = driver;
 } catch (Exception e) {
 throw new RuntimeException(e);
 }
 }

 public String getUrl() {
 return url;
 }

 public void setUrl(String url) {
 this.url = url;
 }

 public String getUser() {
 return user;
 }

 public void setUser(String user) {
 this.user = user;
 }

 public String getPwd() {
 return pwd;
 }

 public void setPwd(String pwd) {
 this.pwd = pwd;
 }

 public Connection getConnection() throws SQLException {
 Connection conn = DriverManager.getConnection(url, user, pwd);
 return conn;
 }

 public void close(Connection conn) {
 if (conn != null) {
 try {
 conn.close();
 } catch (SQLException e) {
 e.printStackTrace();
 }
 }
 }
}

MysqlUserDao类代码如下：

package com.souvc.dao;

import java.io.Serializable;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Repository;

import com.souvc.entity.User;

/** 持久层 注解 */
@Repository("userDao")
// 指定特定的Bean ID 方便setUserDao注入
public class MysqlUserDao implements UserDao, Serializable {
 private static final long serialVersionUID = 7385842613248394287L;
 private JdbcDataSource dataSource;

 public MysqlUserDao() {
 }

 /** 创建 MysqlUserDAO 对象必须依赖于JDBCDataSource实例 */
 public MysqlUserDao(JdbcDataSource dataSource) {
 this.dataSource = dataSource;
 }

 @Autowired
 // 按照类型自动装配
 public void setDataSource(@Qualifier("jdbcDataSource")
 JdbcDataSource dataSource) {
 this.dataSource = dataSource;
 }

 public JdbcDataSource getDataSource() {
 return dataSource;
 }

 /** 根据唯一用户名查询系统用户, 如果没有找到用户信息返回null */
 public User findByName(String name) {
 System.out.println("利用JDBC技术查找User信息");
 String sql = "select id, name, pwd, phone from users where name=?";
 Connection conn = null;
 try {
 conn = dataSource.getConnection();
 PreparedStatement ps = conn.prepareStatement(sql);
 ps.setString(1, name);
 ResultSet rs = ps.executeQuery();
 User user = null;
 while (rs.next()) {
 user = new User();
 user.setId(rs.getInt("id"));
 user.setName(rs.getString("name"));
 user.setPwd(rs.getString("pwd"));
 user.setPhone(rs.getString("phone"));
 }
 rs.close();
 ps.close();
 return user;
 } catch (SQLException e) {
 e.printStackTrace();
 throw new RuntimeException(e);
 } finally {
 dataSource.close(conn);
 }
 }
}

db.properties文件内容如下：

# config for Mysql
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/souvc
user=root
pwd=123456

spring-mvc.xml文件代码如下：

<?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:context="http://www.springframework.org/schema/context"
 xmlns:jdbc="http://www.springframework.org/schema/jdbc"
 xmlns:jee="http://www.springframework.org/schema/jee"
 xmlns:tx="http://www.springframework.org/schema/tx"
 xmlns:jpa="http://www.springframework.org/schema/data/jpa"
 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-3.2.xsd
 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
 http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
 http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
 http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd
 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">

 <util:properties id="jdbcProps" location="classpath:db.properties" />

 <context:component-scan base-package="com.souvc" />
 <!-- 视图处理 -->
 <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
 <property name="prefix" value="/WEB-INF/jsp/"></property>
 <property name="suffix" value=".jsp"></property>
 </bean>
</beans>

MySQL数据库初始化SQL代码如下：

DROP TABLE users;
CREATE TABLE USERS 
(
 ID DOUBLE(7, 0) , 
 NAME VARCHAR(50) , 
 PWD VARCHAR(50), 
 PHONE VARCHAR(50) ,
 PRIMARY KEY (id)
 );

INSERT INTO Users (id, NAME, pwd, phone) VALUES (1, 'Tom', '123', '110');
INSERT INTO Users (id, NAME, pwd, phone) VALUES (2, 'Jerry', 'abc', '119');
INSERT INTO Users (id, NAME, pwd, phone) VALUES (3, 'Andy', '456', '112');

3. 为项目添加JUnit4 API，然后添加测试类TestCase和测试方法[code]testUserService()[/code]用于测试上述配置是否正确。TestCase类代码如下：

package com.souvc.test;

import java.util.Properties;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.souvc.dao.JdbcDataSource;
import com.souvc.entity.User;
import com.souvc.service.UserService;

public class TestCase {

 @Test
 public void testUserService() throws Exception {
 String cfg = "spring-mvc.xml";
 ApplicationContext ac = new ClassPathXmlApplicationContext(cfg);
 Properties obj = ac.getBean("jdbcProps", Properties.class);
 JdbcDataSource ds = ac.getBean("jdbcDataSource", JdbcDataSource.class);
 System.out.println(obj);
 System.out.println(ds);
 System.out.println(ds.getConnection());
 UserService service = ac.getBean("userService", UserService.class);
 User user = service.login("Tom", "123");
 System.out.println(user);
 }
}

执行测试方法[code]testUserService()[/code] ,在控制台输出的结果:

{user=root, url=jdbc:mysql://localhost:3306/souvc, driver=com.mysql.jdbc.Driver, pwd=123456}
com.souvc.dao.JdbcDataSource@1cb1a4e2
com.mysql.jdbc.JDBC4Connection@3d04fc23

利用JDBC技术查找User信息

1,Tom,123,110

这个结果说明业务层UserService工作正常。 4. 配置Spring MVC 核心控制器DispatcherServlet到web.xml。web.xml配置部分代码参考如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 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_2_5.xsd">
 <welcome-file-list>
 <welcome-file>index.jsp</welcome-file>
 </welcome-file-list>

 <servlet>
 <servlet-name>springmvc</servlet-name>
 <servlet-class>
 org.springframework.web.servlet.DispatcherServlet
 </servlet-class>
 <init-param>
 <param-name>contextConfigLocation</param-name>
 <param-value>classpath:spring-mvc.xml</param-value>
 </init-param>
 <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
 <servlet-name>springmvc</servlet-name>
 <url-pattern>*.form</url-pattern>
 </servlet-mapping>

</web-app>

5. 部署项目到Tomcat并且启动，测试Spring MVC配置是否正常。在输出结果中出现内容，并且没有异常就会说明Spring MVC部署正常。步骤二：实现login-action1.form登录流程，测试利用HttpServletRequrst传值方法 1. 在WEB-INF/jsp文件夹下添加login-form.jsp文件，代码如下所示：

<%@ page pageEncoding="utf-8" contentType="text/html; charset=utf-8"%>
<!DOCTYPE HTML>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:url var="base" value="/"></c:url>
<html>
 <head>
 <title>Login Form</title>
 <link rel="stylesheet" type="text/css" href="${base}styles.css" rel="external nofollow" rel="external nofollow" >
 </head>
 <body>
 <h6>${message}</h6>
 <form method="post" action="${base}login/login-action1.form">
 <div>
  <h2>登录 login-action1.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 <form method="post" action="${base}login/login-action2.form">
 <div>
  <h2>登录 login-action2.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 <form method="post" action="${base}login/login-action3.form">
 <div>
  <h2>登录 login-action3.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 <form method="post" action="${base}login/login-action4.form">
 <div>
  <h2>登录 login-action4.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 <form method="post" action="${base}login/login-action5.form">
 <div>
  <h2>登录 login-action5.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 <form method="post" action="${base}login/login-action6.form">
 <div>
  <h2>登录 login-action6.form</h2>
  <p><label>用户</label><input type="text" name="name"></p>
  <p><label>密码</label><input type="password" name="pwd"></p>
  <h3><input type="submit" value="登录"></h3>
 </div>
 </form>
 
 </body>
 </html>

方法一解释：利用HttpServletRequest对象进行浏览器页面到控制器传值。方法二解释：使用@RequestParam注解声明表单密码输入框pwd的值注入到password变量，表单中用户名输入框根据名字映自动射注入name变量。 @RequestMapping注解将login-action2.form映射到了[code]checkLogin2()[/code]方法。这样就与login- form.jsp表单对应。方法三解释：这里采用user作为参数， Spring会自动的将页面表单参数name，pwd注入到user对象的相应属性name,pwd传递到方法中。@RequestMapping将请求login-action3.form映射到方法[code]checkLogin3()[/code] 。方法四解释：在处理方法完成后返回一个ModelAndView对象。方法五解释： ModelMap属性值与页面login-form.jsp之间的数据对应。方法六解释： @ModelAttribute声明的属性与login-form.jsp页面的值关系。用户名或者密码错误时候出现的时候，能够记住用户名。在前述案例中，用户登录成功以后，可以利用HttpServletRequest对象的[code]getSession()[/code]方法访问Session对象，这样就可以保持用户登录状态了。 2. 为页面添加样式文件styles.css，样式文件保存在WebRoot文件夹下，styles.css文件代码如下所示：

* {
 margin: 0;
 padding: 0;
}

h6 {
 text-align: center;
 color: red;
 padding: 10px;
 font-size: 14px;
}

form {
 padding: 10px;
 float: left;
}

form div {
 border: 1px gray solid;
 width: 320px;
 padding: 8px;
}

form p input {
 width: 180px
}

form h2 input {
 text-align: center;
}

form h2 {
 background: black;
 color: white;
 padding: 4px;
}

form p {
 background: #ddd;
 padding: 4px 8px 0 8px;
}

form h3 {
 background: #ddd;
 padding: 8px;
}

3. 在WEB-INF/jsp文件夹下添加success.jsp文件，这个文件是登录成功以后显示的界面，代码如下所示：

<%@ page pageEncoding="utf-8" contentType="text/html; charset=utf-8"%>
<!DOCTYPE HTML>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<c:url var="base" value="/"></c:url>
<html>
 <head>
 <title>Success</title>
 <link rel="stylesheet" type="text/css" href="${base}styles.css" rel="external nofollow" rel="external nofollow" >
 </head>
 <body>
 <h6>
 ${user.name}登录成功！
 </h6>
 </body>
</html>

上述页面中，使用EL表达式和标准标签库配合显示界面数据，其中[code]<c:url var="base" value="/"></c:url>[/code]和[code]${base}[/code]用于解决绝对路径问题。 4. 创建控制器类LoginController，在该类中使用注解@Controller的方式进行配置： 1）使用@Controller将LoginController声明为控制器Bean组件。 2）使用[code]@RequestMapping("/login")[/code]声明对LoginController组件的请求在/login 路径下。 3）流程控制方法loginForm()，用于显示登录表单页面。使用@RequestMapping注解将映射请求/login-form.form到loginForm()方法。 4）增加userService属性，并且使用@Resource注解声明在运行期间注入userService对象。 5）增加控制流程方法[code]checkLogin1() [/code]，使用@RequestMapping注解将请求/login-action1.form映射到checkLogin1()方法。[code]checkLogin1()[/code]方法调用userService的login方法，实现登录流程。 [code]checkLogin1()[/code]方法主要是测试JSP页面到控制器的数据传输方式。 LoginController类代码如下所示：

package com.souvc.controller;

import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

import com.souvc.entity.User;
import com.souvc.service.NameOrPwdException;
import com.souvc.service.NullParamException;
import com.souvc.service.UserService;

@Controller
//@SessionAttributes("user")
@RequestMapping("/login")
public class LoginController {

 @Resource
 // 请求Spring注入资源 userService
 private UserService userService;

 @RequestMapping("/login.form")
 public String loginForm() {
 // 可以向表单界面传递一些参数
 return "login-form";
 }

 @RequestMapping("/login-action1.form")
 // Spring MVC 自动参数注入HttpServletRequest
 public String checkLogin1(HttpServletRequest req) {
 System.out.println("---方法一---");
 // 优点直接简洁，缺点需要自己处理数据类型转换， 不支持文件上传功能
 String name = req.getParameter("name");
 String pwd = req.getParameter("pwd");
 System.out.println(name);
 System.out.println(pwd);
 try {
  User user = userService.login(name, pwd);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "login-form";
 } catch (NullParamException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "redirect:login.form";
 } catch (RuntimeException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "error";
 }
 }

 @RequestMapping("/login-action2.form")
 public String checkLogin2(String name, @RequestParam("pwd")
 String password, // 映射表单属性不同的参数
  HttpServletRequest req) {
 System.out.println("---方法二---");
 // 优点， 自动转换数据类型， 缺点可能出现数据类型转换异常
 System.out.println(name);
 System.out.println(password);
 try {
  User user = userService.login(name, password);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "login-form";
 } catch (NullParamException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "login-form";
 } catch (RuntimeException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "error";
 }
 }

 @RequestMapping("/login-action3.form")
 public String checkLogin3(User user, HttpServletRequest req) {
 System.out.println("---方法三---");
 // 自动填充到bean对象
 System.out.println(user);
 try {
  user = userService.login(user.getName(), user.getPwd());
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "login-form";
 } catch (NullParamException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "login-form";
 } catch (RuntimeException e) {
  e.printStackTrace();
  req.setAttribute("message", e.getMessage());
  return "error";
 }
 }

 @RequestMapping("/login-action4.form")
 public ModelAndView checkLogin4(String name, String pwd,
  HttpServletRequest req) {
 System.out.println("---方法四---");
 Map<String, Object> data = new HashMap<String, Object>();
 try {
  User user = userService.login(name, pwd);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return new ModelAndView("success", data);
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  data.put("message", e.getMessage());
  return new ModelAndView("login-form", data);
 } catch (NullParamException e) {
  e.printStackTrace();
  data.put("message", e.getMessage());
  return new ModelAndView("login-form", data);
 } catch (RuntimeException e) {
  e.printStackTrace();
  data.put("message", e.getMessage());
  return new ModelAndView("error", data);
 }
 }

 @RequestMapping("/login-action5.form")
 public String checkLogin5(String name, String pwd, ModelMap model,
  HttpServletRequest req) {
 System.out.println("---方法五---");
 try {
  User user = userService.login(name, pwd);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "login-form";
 } catch (NullParamException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "login-form";
 } catch (RuntimeException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "error";
 }
 }

 @RequestMapping("/login-action6.form")
 public String checkLogin6(
  @ModelAttribute("name") String name, 
  @ModelAttribute("password") String pwd,
  ModelMap model, HttpServletRequest req){
  System.out.println("---方法六---");
  try {
  User user = userService.login(name, pwd);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
  } catch (NameOrPwdException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "login-form";
  } catch (NullParamException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "login-form";
  } catch (RuntimeException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "error";
  }
 }
 
 @RequestMapping("/login-action7.form")
 public String checkLogin7(ModelMap model, HttpServletRequest req) {
 System.out.println("---方法七---");
 String name1=req.getParameter("name");
 String pwd1=req.getParameter("pwd");
 try {
  User user = userService.login(name1, pwd1);
  // 登录成功将登录用户信息保存到当前会话中
  req.getSession().setAttribute("user", user);
  return "success";
 } catch (NameOrPwdException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "redirect：login";
 } catch (NullParamException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "redirect：login";
 } catch (RuntimeException e) {
  e.printStackTrace();
  model.addAttribute("message", e.getMessage());
  return "error";
 }
 }

 private String[] msg = { "再来一次", "下次就对了", "没关系还有机会" };

 @ModelAttribute("next")
 public String getNext() {
 Random r = new Random();
 return msg[r.nextInt(msg.length)];
 }

}

5.测试login-action1.form登录流程通过网址“http://localhost:8080/SpringValues/login/login.form”请求Tomcat服务器：访问请求的信息打印在控制台：

---方法一---
Tom
123
利用JDBC技术查找User信息
---方法二---
Tom
123
利用JDBC技术查找User信息
---方法三---
0,Tom,123,null
利用JDBC技术查找User信息
---方法四---
利用JDBC技术查找User信息
---方法五---
利用JDBC技术查找User信息

[b]总结[/b] 以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对编程素材网的支持。

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