创建环境
- 系统:macOS
- Java:1.8
- 软件:eclipse,maven,mysql
创建步骤
本例:创建一个Maven项目(SpringMVC+Spring+Mybatis),页面上展示员工列表(页面发起请求-访问web项目-查询数据库)
创建数据库
1、创建数据库和表,如下:
创建sql如下:
1 CREATE DATABASE test_mybatis; 2 USE test_mybatis; 3 4 -- ---------------------------- 5 -- Table structure for employee 6 -- ---------------------------- 7 DROP TABLE IF EXISTS `employee`; 8 CREATE TABLE `employee` ( 9 `id` int(11) NOT NULL AUTO_INCREMENT, 10 `last_name` varchar(255) DEFAULT NULL, 11 `gender` char(1) DEFAULT NULL, 12 `email` varchar(255) DEFAULT NULL, 13 `dept_id` int(11) DEFAULT NULL COMMENT '部门ID', 14 PRIMARY KEY (`id`) 15 ) ENGINE=InnoDB AUTO_INCREMENT=36 DEFAULT CHARSET=utf8; 16 17 -- ---------------------------- 18 -- Records of employee 19 -- ---------------------------- 20 BEGIN; 21 INSERT INTO `employee` VALUES (1, '大白', '1', 'dabai@163.com', 1); 22 INSERT INTO `employee` VALUES (2, '小明', '1', 'xiaoming@163.com', 1); 23 INSERT INTO `employee` VALUES (3, '小红', '1', 'xiaohong@163.com', 1); 24 COMMIT;
创建web项目
1、创建一个Maven Web项目,可以参照:【Maven】Eclipse 使用Maven创建Java Web项目
2、编辑pom文件,添加SpringMVC+Spring+Mybatis的相关依赖
1 <project xmlns="http://maven.apache.org/POM/4.0.0" 2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <groupId>com.hd</groupId> 6 <artifactId>test-spring-mybatis</artifactId> 7 <packaging>war</packaging> 8 <version>1.0.0-SNAPSHOT</version> 9 <url>http://maven.apache.org</url> 10 11 <!-- 定义maven变量 --> 12 <properties> 13 <!-- spring --> 14 <spring.version>5.1.4.RELEASE</spring.version> 15 16 <!-- Mybatis --> 17 <mybatis.version>3.5.0</mybatis.version> 18 <!-- Mybatis 整合 Spring --> 19 <mybatis-spring.version>2.0.0</mybatis-spring.version> 20 21 <!-- mysql --> 22 <mysql.version>8.0.13</mysql.version> 23 24 <!-- c3p0 连接池 --> 25 <c3p0.version>0.9.5.4</c3p0.version> 26 27 <!-- logback --> 28 <slf4j-api.version>1.7.5</slf4j-api.version> 29 <logback.version>0.9.30</logback.version> 30 31 <!-- Servlet --> 32 <servlet.version>3.0.1</servlet.version> 33 <jsp-api.version>2.2</jsp-api.version> 34 35 <!-- jstl --> 36 <jstl.version>1.2</jstl.version> 37 <standard.version>1.1.2</standard.version> 38 39 <!-- test junit --> 40 <junit.version>3.8.1</junit.version> 41 42 <!-- jdk --> 43 <jdk.version>1.8</jdk.version> 44 <maven.compiler.plugin.version>2.3.2</maven.compiler.plugin.version> 45 </properties> 46 47 48 <dependencies> 49 50 <!-- Spring IOC 核心容器 --> 51 <dependency> 52 <groupId>org.springframework</groupId> 53 <artifactId>spring-core</artifactId> 54 <version>${spring.version}</version> 55 </dependency> 56 57 <dependency> 58 <groupId>org.springframework</groupId> 59 <artifactId>spring-beans</artifactId> 60 <version>${spring.version}</version> 61 </dependency> 62 63 <dependency> 64 <groupId>org.springframework</groupId> 65 <artifactId>spring-context</artifactId> 66 <version>${spring.version}</version> 67 </dependency> 68 69 <dependency> 70 <groupId>org.springframework</groupId> 71 <artifactId>spring-expression</artifactId> 72 <version>${spring.version}</version> 73 </dependency> 74 75 <!-- Spring AOP 切面 模块 --> 76 <dependency> 77 <groupId>org.springframework</groupId> 78 <artifactId>spring-aop</artifactId> 79 <version>${spring.version}</version> 80 </dependency> 81 82 <!-- Spring WEB MVC 模块 --> 83 <dependency> 84 <groupId>org.springframework</groupId> 85 <artifactId>spring-web</artifactId> 86 <version>${spring.version}</version> 87 </dependency> 88 89 <dependency> 90 <groupId>org.springframework</groupId> 91 <artifactId>spring-webmvc</artifactId> 92 <version>${spring.version}</version> 93 </dependency> 94 95 <!-- Spring 事物 模块 --> 96 <dependency> 97 <groupId>org.springframework</groupId> 98 <artifactId>spring-tx</artifactId> 99 <version>${spring.version}</version> 100 </dependency> 101 102 <!-- Spring ORM 对象关系映射 模块 --> 103 <dependency> 104 <groupId>org.springframework</groupId> 105 <artifactId>spring-orm</artifactId> 106 <version>${spring.version}</version> 107 </dependency> 108 109 <!-- Spring JDBC 模块 --> 110 <dependency> 111 <groupId>org.springframework</groupId> 112 <artifactId>spring-jdbc</artifactId> 113 <version>${spring.version}</version> 114 </dependency> 115 116 <!-- Mybatis --> 117 <dependency> 118 <groupId>org.mybatis</groupId> 119 <artifactId>mybatis</artifactId> 120 <version>${mybatis.version}</version> 121 </dependency> 122 123 <!-- Mybatis 整合 Spring --> 124 <dependency> 125 <groupId>org.mybatis</groupId> 126 <artifactId>mybatis-spring</artifactId> 127 <version>${mybatis-spring.version}</version> 128 </dependency> 129 130 <!-- mysql --> 131 <dependency> 132 <groupId>mysql</groupId> 133 <artifactId>mysql-connector-java</artifactId> 134 <version>${mysql.version}</version> 135 </dependency> 136 137 <!-- c3p0 连接池 --> 138 <!-- https://mvnrepository.com/artifact/c3p0/c3p0 --> 139 <dependency> 140 <groupId>com.mchange</groupId> 141 <artifactId>c3p0</artifactId> 142 <version>${c3p0.version}</version> 143 </dependency> 144 145 146 <!-- logback --> 147 <dependency> 148 <groupId>org.slf4j</groupId> 149 <artifactId>slf4j-api</artifactId> 150 <version>${slf4j-api.version}</version> 151 <type>jar</type> 152 <scope>compile</scope> 153 </dependency> 154 155 <dependency> 156 <groupId>ch.qos.logback</groupId> 157 <artifactId>logback-core</artifactId> 158 <version>${logback.version}</version> 159 <type>jar</type> 160 </dependency> 161 162 <dependency> 163 <groupId>ch.qos.logback</groupId> 164 <artifactId>logback-classic</artifactId> 165 <version>${logback.version}</version> 166 <type>jar</type> 167 </dependency> 168 169 <dependency> 170 <groupId>ch.qos.logback</groupId> 171 <artifactId>logback-access</artifactId> 172 <version>${logback.version}</version> 173 </dependency> 174 175 176 <!-- Servlet --> 177 <dependency> 178 <groupId>javax.servlet</groupId> 179 <artifactId>javax.servlet-api</artifactId> 180 <version>${servlet.version}</version> 181 <scope>provided</scope> 182 </dependency> 183 <dependency> 184 <groupId>javax.servlet.jsp</groupId> 185 <artifactId>jsp-api</artifactId> 186 <version>${jsp-api.version}</version> 187 <scope>provided</scope> 188 </dependency> 189 190 <!-- jstl --> 191 <dependency> 192 <groupId>javax.servlet</groupId> 193 <artifactId>jstl</artifactId> 194 <version>${jstl.version}</version> 195 </dependency> 196 197 <dependency> 198 <groupId>taglibs</groupId> 199 <artifactId>standard</artifactId> 200 <version>${standard.version}</version> 201 </dependency> 202 203 <!-- test --> 204 <dependency> 205 <groupId>junit</groupId> 206 <artifactId>junit</artifactId> 207 <version>${junit.version}</version> 208 <scope>test</scope> 209 </dependency> 210 211 </dependencies> 212 213 <build> 214 <plugins> 215 <!-- define the project compile level --> 216 <plugin> 217 <groupId>org.apache.maven.plugins</groupId> 218 <artifactId>maven-compiler-plugin</artifactId> 219 <version>${maven.compiler.plugin.version}</version> 220 <configuration> 221 <source>${jdk.version}</source> 222 <target>${jdk.version}</target> 223 </configuration> 224 </plugin> 225 </plugins> 226 <finalName>test_spring_mybatis</finalName> 227 </build> 228 </project>
3、编辑web.xml文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 5 6 <display-name>test_spring_mybatis</display-name> 7 8 <!--指定Spring的配置在文件所在的目录,默认配置在WEB-INF目录下--> 9 <context-param> 10 <param-name>contextConfigLocation</param-name> 11 <param-value>classpath:spring-context.xml</param-value> 12 </context-param> 13 14 <!-- Spring配置:needed for ContextLoaderListener --> 15 <!-- Bootstraps the root web application context before servlet initialization --> 16 <listener> 17 <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 18 </listener> 19 20 <!-- Spring MVC配置 --> 21 <!-- The front controller of this Spring Web application, responsible for 22 handling all application requests --> 23 <servlet> 24 <servlet-name>spring</servlet-name> 25 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 26 <!-- 可以自定义servlet.xml配置文件的位置和名称,默认为WEB-INF目录下,名称为[<servlet-name>]-servlet.xml,如spring-servlet.xml --> 27 <init-param> 28 <param-name>contextConfigLocation</param-name> 29 <param-value>classpath:spring-mvc.xml</param-value> 30 </init-param> 31 <load-on-startup>1</load-on-startup> 32 </servlet> 33 34 <!-- Map all requests to the DispatcherServlet for handling --> 35 <servlet-mapping> 36 <servlet-name>spring</servlet-name> 37 <url-pattern>/</url-pattern> 38 </servlet-mapping> 39 40 <!-- 中文过滤器 --> 41 <filter> 42 <filter-name>CharacterEncodingFilter</filter-name> 43 <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> 44 <init-param> 45 <param-name>encoding</param-name> 46 <param-value>UTF-8</param-value> 47 </init-param> 48 <init-param> 49 <param-name>forceEncoding</param-name> 50 <param-value>true</param-value> 51 </init-param> 52 </filter> 53 <filter-mapping> 54 <filter-name>CharacterEncodingFilter</filter-name> 55 <url-pattern>/*</url-pattern> 56 </filter-mapping> 57 58 </web-app>
4、在src/main/resources,新建一个spring-mvc.xml的配置文件,进行Spring-MVC相关配置
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xmlns:mvc="http://www.springframework.org/schema/mvc" 6 xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd 7 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> 9 10 <!--SpringMVC只是控制网站跳转逻辑 --> 11 <!-- 只扫描控制器 --> 12 <context:component-scan base-package="com.test.mybatis" use-default-filters="false"> 13 <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> 14 </context:component-scan> 15 16 <!-- 视图解析器 --> 17 <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 18 <property name="prefix" value="/WEB-INF/pages/"></property> 19 <property name="suffix" value=".jsp"></property> 20 </bean> 21 22 <!-- 默认的注解映射的支持 --> 23 <mvc:annotation-driven></mvc:annotation-driven> 24 25 <!-- 对静态资源文件的访问 --> 26 <mvc:default-servlet-handler/> 27 28 </beans>
5、在src/main/resources,新建一个spring-context.xml的配置文件,进行Spring相关配置
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring" 6 xmlns:tx="http://www.springframework.org/schema/tx" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd 9 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd 10 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> 11 12 <!-- Sprin望管理所有的业务逻辑组件等 --> 13 <context:component-scan base-package="com.test.mybatis"> 14 <context:exclude-filter type="annotation" 15 expression="org.springframework.stereotype.Controller" /> 16 </context:component-scan> 17 18 <!-- 导入spring整合mybatis配置文件 --> 19 <import resource="classpath:spring-mybatis.xml" /> 20 </beans>
6、在src/main/resources,新建一个spring-mybatis.xml的配置文件,进行Spring与Mybatis整合相关配置
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring" 6 xmlns:tx="http://www.springframework.org/schema/tx" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans 8 http://www.springframework.org/schema/beans/spring-beans.xsd 9 http://mybatis.org/schema/mybatis-spring 10 http://mybatis.org/schema/mybatis-spring.xsd 11 http://www.springframework.org/schema/tx 12 http://www.springframework.org/schema/tx/spring-tx-4.0.xsd 13 http://www.springframework.org/schema/context 14 http://www.springframework.org/schema/context/spring-context-4.0.xsd"> 15 16 <!-- 引入数据库的配置文件 --> 17 <context:property-placeholder location="classpath:dbconfig.properties" /> 18 19 <!-- 数据源:Spring用来控制业务逻辑。数据源、事务控制、aop --> 20 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 21 <property name="jdbcUrl" value="${jdbc.url}"></property> 22 <property name="driverClass" value="${jdbc.driver}"></property> 23 <property name="user" value="${jdbc.username}"></property> 24 <property name="password" value="${jdbc.password}"></property> 25 </bean> 26 <!-- spring事务管理 --> 27 <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> 28 <property name="dataSource" ref="dataSource"></property> 29 </bean> 30 31 <!-- 开启基于注解的事务 --> 32 <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/> 33 34 <!-- 35 整合mybatis 36 目的:1、spring管理所有组件。mapper的实现类。 37 service==>Dao @Autowired:自动注入mapper; 38 2、spring用来管理事务,spring声明式事务 39 --> 40 <!--创建出SqlSessionFactory对象 --> 41 <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean"> 42 <property name="dataSource" ref="dataSource"></property> 43 <!-- configLocation指定全局配置文件的位置 --> 44 <property name="configLocation" value="classpath:mybatis-config.xml"></property> 45 <!--mapperLocations: 指定mapper文件的位置--> 46 <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml"></property> 47 </bean> 48 49 <!--配置一个可以进行批量执行的sqlSession --> 50 <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"> 51 <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"></constructor-arg> 52 <constructor-arg name="executorType" value="BATCH"></constructor-arg> 53 </bean> 54 55 <!-- 扫描所有的mapper接口的实现,让这些mapper能够自动注入; 56 base-package:指定mapper接口的包名 57 --> 58 <mybatis-spring:scan base-package="com.test.mybatis.dao"/> 59 60 </beans>
7、在src/main/resources,新建一个mybatis-config.xml的配置文件,相当于mybatis的全局配置文件,进行Mybatis相关配置
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE configuration 3 PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-config.dtd"> 5 <configuration> 6 <!-- 7 2、settings包含含多重要的设置项 8 setting:用来设置每一个设置项 9 name:设置项名字 10 values:设置项取值 11 --> 12 <settings> 13 <setting name="mapUnderscoreToCamelCase" value="true"/> 14 15 <!--显示的指定每个我们需要更改的配置的值,即使他是默认的。防止版本更新带来的问题 --> 16 <!-- <setting name="lazyloadingenabled" value="true"/> 17 <setting name="aggressivelazyloading" value="false"/> --> 18 19 <!-- 设置二级缓存,默认是true --> 20 <setting name="cacheEnabled" value="true"/> 21 </settings> 22 23 </configuration>
8、在src/main/resources,新建一个dbconfig.properties的配置文件,配置数据库连接的相关信息
jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://127.0.0.1:3306/test_mybatis?allowPublicKeyRetrieval=true
jdbc.username = admin
jdbc.password = 123456
代码编写
1、在src/main/java的com.test.mybatis.controller,新建一个类TestController.java
1 package com.test.mybatis.controller; 2 3 import java.util.List; 4 import java.util.Map; 5 6 import org.springframework.beans.factory.annotation.Autowired; 7 import org.springframework.stereotype.Controller; 8 import org.springframework.web.bind.annotation.RequestMapping; 9 10 import com.test.mybatis.pojo.Employee; 11 import com.test.mybatis.service.EmployeeService; 12 13 @Controller 14 public class TestController { 15 16 17 @Autowired 18 EmployeeService employeeService; 19 20 @RequestMapping("/getEmps") 21 public String emps(Map<String,Object> map){ 22 List<Employee> emps = employeeService.getEmps(); 23 System.out.println(emps.size()); 24 map.put("allEmps", emps); 25 return "list"; 26 } 27 28 }
2、在src/main/java的com.test.mybatis.service,新建一个类EmployeeService.java
1 package com.test.mybatis.service; 2 3 import java.util.List; 4 5 import org.springframework.beans.factory.annotation.Autowired; 6 import org.springframework.stereotype.Service; 7 import org.springframework.transaction.annotation.Transactional; 8 9 import com.test.mybatis.dao.EmployeeMapper; 10 import com.test.mybatis.pojo.Employee; 11 12 @Service 13 @Transactional 14 public class EmployeeService { 15 16 @Autowired 17 private EmployeeMapper employeeMapper; 18 19 public List<Employee> getEmps() { 20 return employeeMapper.getEmployee(); 21 } 22 23 }
3、在src/main/java的com.test.mybatis.dao,新建一个类EmployeeMapper.java
package com.test.mybatis.dao; import java.util.List; import java.util.Map; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.Select; import org.springframework.stereotype.Repository; import com.test.mybatis.pojo.Employee; @Repository public interface EmployeeMapper { public List<Employee> getEmployee(); }
4、在src/main/java的com.test.mybatis.pojo,新建一个类Employee.java
1 package com.test.mybatis.pojo; 2 3 import java.io.Serializable; 4 5 6 public class Employee implements Serializable{ 7 8 private Integer id; 9 private String lastName; 10 private String gender; 11 private String email; 12 13 14 public Employee() { 15 // TODO Auto-generated constructor stub 16 } 17 18 19 public Employee(String lastName, String gender, String email) { 20 super(); 21 this.lastName = lastName; 22 this.gender = gender; 23 this.email = email; 24 } 25 26 27 28 public Employee(Integer id, String lastName, String gender, String email) { 29 super(); 30 this.id = id; 31 this.lastName = lastName; 32 this.gender = gender; 33 this.email = email; 34 } 35 36 37 public Integer getId() { 38 return id; 39 } 40 public void setId(Integer id) { 41 this.id = id; 42 } 43 public String getLastName() { 44 return lastName; 45 } 46 public void setLastName(String lastName) { 47 this.lastName = lastName; 48 } 49 public String getGender() { 50 return gender; 51 } 52 public void setGender(String gender) { 53 this.gender = gender; 54 } 55 public String getEmail() { 56 return email; 57 } 58 public void setEmail(String email) { 59 this.email = email; 60 } 61 @Override 62 public String toString() { 63 return "Employee [id=" + id + ", lastName=" + lastName + ", gender=" + gender + ", email=" + email + "]"; 64 } 65 66 67 }
5、在src/main/resources/mybatis/mapper,新增EmployeeMapper.xml文件
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 3 <!-- namespace:名称空间 id:唯一标识 resultType:返回值类型 #{id}:从传过来的参数中取出id值 --> 4 <mapper namespace="com.test.mybatis.dao.EmployeeMapper"> 5 <!-- 6 <cache eviction="FIFO" flushInterval="60000" readOnly="false" size="1024"></cache> 7 --> 8 <select id="getEmployee" 9 resultType="com.test.mybatis.pojo.Employee"> 10 select id, last_name lastName, gender, email from employee 11 </select> 12 13 </mapper>
6、编辑首页index.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <html> 4 5 <body> 6 <h2>Hello World!</h2> 7 <a href="getEmps">获取员工列表</a> 8 </body> 9 </html>
7、在webapp/WEB-INF/pages,中新增用户列表页list.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 4 <!DOCTYPE html> 5 <html> 6 <head> 7 <meta charset="UTF-8"> 8 <title>Insert title here</title> 9 </head> 10 <body> 11 员工列表 12 <table> 13 <tr> 14 <th>id</th> 15 <th>lastName</th> 16 <th>gender</th> 17 <th>email</th> 18 </tr> 19 <c:forEach items="${allEmps }" var="emp"> 20 <tr> 21 <td>${emp.id }</td> 22 <td>${emp.lastName }</td> 23 <td>${emp.gender }</td> 24 <td>${emp.email}</td> 25 </tr> 26 </c:forEach> 27 </table> 28 </body> 29 </html>
测试
项目最终的目录结构
1、启动web项目
2、在浏览器中访问,地址:localhost:8080/test_spring_mybatis,点击员工列表