基于Maven构建的Spring+Mybatis项目

完整的项目结构：

1.基于Maven构建Web项目

参考：基于Maven构建Web项目

2.导入项目依赖

Spring
核心容器（Beans、Core、Context、Context support、Expression）

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-expression</artifactId>
    <version>${springframework.version}</version>
</dependency>

面向切面编程（Aop、Aspects）

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>${springframework.version}</version>
</dependency>

Web调用

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>${springframework.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>${springframework.version}</version>
</dependency>

因为spring-webmvc依赖于spring-web，所以在pom.xml中不需要显式导入spring-web。
数据访问

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>${springframework.version}</version>
</dependency>

mybatis

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.6</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>1.3.2</version>
</dependency>

mysql

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.38</version>
</dependency>

c3p0

<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5.2</version>
</dependency>

JSTL

<dependency>
    <groupId>jstl</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>
<dependency>
    <groupId>taglibs</groupId>
    <artifactId>standard</artifactId>
    <version>1.1.2</version>
</dependency>

最终Maven依赖的包如下图所示：

扫描二维码关注公众号，回复： 4133104 查看本文章

3. 编写配置文件

部署描述符web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>spring5_mybatis3</display-name>
  <!-- needed for ContextLoaderListener -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>

    <!-- Bootstraps the root web application context before servlet initialization -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    
    <filter>
        <filter-name>CharacterEncodingFilter</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>
    </filter>
    
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
  
  <!-- The front controller of this Spring Web application, responsible for handling all application requests -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- Map all requests to the DispatcherServlet for handling -->
    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

Spring的配置文件applicationContext.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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
    xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <context:component-scan base-package="com.mybatis">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    
    <context:property-placeholder location="classpath:dbconfig.properties"/>
    
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <tx:annotation-driven transaction-manager="transactionManager"/>
    
    <!-- 整合mybatis -->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
        <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml"></property>
    </bean>
    
    <mybatis-spring:scan base-package="com.mybatis.dao"/>
    
</beans>

dbconfig.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useSSL=false
jdbc.username=root
jdbc.password=root

Spring MVC的配置文件springmvc.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:context="http://www.springframework.org/schema/context"
    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/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">

    <context:component-scan base-package="com.mybatis" use-default-filters="false">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    
    <mvc:annotation-driven></mvc:annotation-driven>
    <mvc:default-servlet-handler/>
</beans>

Mybatis的配置文件mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <setting name="lazyLoadingEnabled" value="true"/>
        <setting name="aggressiveLazyLoading" value="false"/>
        <!-- 打印查询语句 -->
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
</configuration>

loj4j.properties

#定义LOG输出级别  
log4j.rootLogger=DEBUG,INFO,Console,File  
#定义日志输出目的地为控制台  
log4j.appender.Console=org.apache.log4j.ConsoleAppender  
log4j.appender.Console.Target=System.out  
#可以灵活地指定日志输出格式，下面一行是指定具体的格式  
log4j.appender.Console.layout = org.apache.log4j.PatternLayout  
log4j.appender.Console.layout.ConversionPattern = [%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m  %l%n
 
#文件大小到达指定尺寸的时候产生一个新的文件  
log4j.appender.File = org.apache.log4j.RollingFileAppender  
#指定输出目录  
log4j.appender.File.File = logs/ssm.log  
#定义文件最大大小  
log4j.appender.File.MaxFileSize = 10MB  
#输出所以日志，如果换成DEBUG表示输出DEBUG以上级别日志  
log4j.appender.File.Threshold = ALL  
log4j.appender.File.layout = org.apache.log4j.PatternLayout  
log4j.appender.File.layout.ConversionPattern = [%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m  %l%n
#mybatis日志配置 需要将日志的输出级别调为debug
log4j.logger.com.ibatis=DEBUG
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUG
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=DEBUG
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=DEBUG
#与sql相关
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

两步实现在Eclipse中打印SQL语句

1. 在类路径下添加log4j.properties文件。
2. 在mybatis-config.xml中添加<setting name="logImpl" value="STDOUT_LOGGING"/>。

4. 编写源代码

实体类

public class Employee {
    private Integer id;
    private String lastName;
    private String email;
    private String gender;
    private Department dept;
    
    //setter and getter
    
}

public class Department {
    private Integer id;
    private String departmentName;
    private List<Employee> employees;
    
    //setter and getter
    
}

如果启用了mybatis的缓存，则实体类需要实现Serializable接口。
Mapper

package com.mybatis.dao;

import java.util.List;

import com.mybatis.bean.Employee;

public interface EmployeeMapper {
    
    public Employee getEmpById(Integer id);
    
    public List<Employee> getEmps();
}

<?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.mybatis.dao.EmployeeMapper">
    <!-- public Employee getEmpById(Integer id); -->
    <select id="getEmpById" resultType="com.mybatis.bean.Employee">
        select * from tb_employee where id=#{id}
    </select>
    
    <!--public List<Employee> getEmps();  -->
    <select id="getEmps" resultType="com.mybatis.bean.Employee">
        select * from tb_employee
    </select>
</mapper>

Service

package com.mybatis.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.mybatis.bean.Employee;
import com.mybatis.dao.EmployeeMapper;

@Service
public class EmployeeService {
    
    @Autowired
    private EmployeeMapper employeeMapper;
    
//  @Autowired
//  private SqlSession sqlSession;
    
    public List<Employee> getEmps(){
        //
        //EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);
        return employeeMapper.getEmps();
    }

}

Controller

package com.mybatis.controller;

import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.mybatis.bean.Employee;
import com.mybatis.service.EmployeeService;

@Controller
public class EmployeeController {
    
    @Autowired
    private EmployeeService employeeService;
    
    @RequestMapping("/getemps")
    public String emps(Map<String,Object> map){
        List<Employee> emps = employeeService.getEmps();
        map.put("allEmps", emps);
        return "list";
    }

}

JSP页面

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<html>
    <body>
        <a href="getemps">查询所有员工</a>
    </body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>员工列表</title>
</head>
<body>
    <table>
        <tr>
            <td>id</td>
            <td>lastName</td>
            <td>email</td>
            <td>gender</td>
        </tr>
        <c:forEach items="${allEmps }" var="emp">
            <tr>
                <td>${emp.id }</td>
                <td>${emp.lastName }</td>
                <td>${emp.email }</td>
                <td>${emp.gender }</td>
            </tr>
        </c:forEach>
    </table>
</body>
</html>

启动项目之前，需要在MYSQL中新建数据库和表。

注：这篇随笔的目的在于熟悉使用Maven构建Spring整合MyBatis的Web项目的过程。