SpringMVC + Mybatis 实现用户登录功能

因业务需要，刚刚接触Web编程。之前仅有移动端经验，一个简单的登录功能，都花费了不少功夫，当然部分原因是想尽量遵循框架的规范。

实现过程参考了

Spring学习之SpringMVC框架快速搭建实现用户登录功能

mybatis实战教程(mybatis in action),mybatis入门到精通

感谢两位的分享。

1.首先配置web.xml，以.do结尾的请求，将通过DispatcherServlet分发，DispatchServlet的详细配置则指向了applicationContext.xml

<?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"> <display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- Spring配置文件 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Dispatcher</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>

2.接下来看看applicationContext.xml。第一个bean，将login.do的action控制指向loginController，等一下将在这个类中定义控制逻辑。然后进行数据库定义，mapper指向实体类对应的xml，后面介绍。
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"
default-autowire="byName" default-lazy-init="false">
<bean id="loginController" class="com.MoonShine.controller.LoginController">
<!-- 注意这里的两个属性，对应的是两个需要跳转的页面，一个是显示用户，一个是登录失败还是登录界面 -->
<property name="successView" value="default"></property>
<property name="failView" value="login"></property>
</bean>
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/login.do">loginController</prop>
</props>
</property>
</bean>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"></property>
<property name="suffix" value=".jsp"></property>
</bean>

<!--使用Mybatis，采用DBCP连接池，应预先把DBCP的jar包复制到工程的lib目录下。 -->
<context:property-placeholder location="classpath:/config/database.properties" />
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close" p:driverClassName="oracle.jdbc.OracleDriver"
p:url="jdbc:oracle:thin:@192.168.0.1:1521:orcl"
p:username="root" p:password="asshole"
p:maxActive="10" p:maxIdle="10">
</bean>

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--dataSource属性指定要用到的连接池-->
<property name="dataSource" ref="dataSource"/>
<!--configLocation属性指定mybatis的核心配置文件-->
<property name="configLocation" value="classpath:config/Configuration.xml" />
<!-- 所有配置的mapper文件 -->
<property name="mapperLocations" value="classpath*:com/MoonShine/mapper/*.xml" />
</bean>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.MoonShine.inter" />
</bean>
</beans>

3.先来看看实体类，务必写一个全属性的构造函数，程序将会通过这个构造函数将数据注入。
package com.MoonShine.model;

public class User {
private String userId;
private String password;
private String userName;

public User(String userId, String password, String userName) {
super();
this.userId = userId;
this.password = password;
this.userName = userName;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public String getUserId(){
return userId;
}

public void setUserId(String userId) {
this.userId = userId;
}

public String getUserName() {
return userName;
}

public void setUserName(String userName) {
this.userName = userName;
}

}


4.定义一个数据操作接口
package com.MoonShine.inter;

import com.MoonShine.model.User;

public interface IUserOperation {
public User selectUserByID(String id);
}

5.实体类对应的xml，配置执行动作。id="selectUserByID"与第4步的接口定义的方法必须对应。注意，sql语句中的属性名必须和第3步的实体类中的属性一一对应，即select查询出来的column必须是userId, password, userName，如果不同就不能正确注入数据，可以通过定义别名的方法修改语句，定义别名的方法请自行百度。

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.MoonShine.inter.IUserOperation">

<select id="selectUserByID" parameterType="String" resultType="User">
<span style="font-family: Arial; font-size: 14px; line-height: 26px;">select * from `user` where id = #{id}</span>
</select>

</mapper>

6.最后是LoginController，成员successView和failView对应ApplicationContext.xml中定义的属性，用来作为登录成功或失败的跳转目标。@Autowired自动注入数据，然后通过user = userMapper.selectUserByID(userId)得到数据库中的值，将request.getParameter("password")与user.getPassword()进行对比，如果一样，说明密码正确，登录成功，否则失败，分别跳转到相应页面。
package com.MoonShine.controller;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;
import org.springframework.beans.factory.annotation.Autowired;

import com.MoonShine.inter.IUserOperation;
import com.MoonShine.model.User;

public class LoginController extends AbstractController {
//成功与失败字段
private String successView;
private String failView;

@Autowired
IUserOperation userMapper;

public String getSuccessView() {
return successView;
}

public void setSuccessView(String successView) {
this.successView = successView;
}

public String getFailView() {
return failView;
}

public void setFailView(String failView) {
this.failView = failView;
}

@Override
protected ModelAndView handleRequestInternal(HttpServletRequest request,
HttpServletResponse response) throws Exception {
//不应该是这样写，但是这样看起来比较容易理解
response
9354
.setContentType("text/html");
response.setCharacterEncoding("GBK");

String userId = request.getParameter("userId");
String password = request.getParameter("password");
User user = null;

try{
user = userMapper.selectUserByID(userId);
System.out.println(user.getUserId());
<span style="white-space:pre"> </span>System.out.println(user.getPassword());
<span style="white-space:pre"> </span>System.out.println(user.getUserName());
}
catch(Exception e){
user = null;
}

//保存相应的参数，通过ModelAndView返回
Map<String ,Object> model=new HashMap<String,Object>();
if(user!=null && user.getPassword().equals(password)){
model.put("user", user);
return new ModelAndView(getSuccessView(),model);
}else{
model.put("error", "用户名或密码输入错误！！！");
return new ModelAndView(getFailView(),model);
}
}

}