ssm简单整合mybatis-plus（详细步骤分享）

ssm整合mybatis-plus

• 一、准备工作
• • 1、创建表
  • 2、加入依赖
  • 3、加入各种配置文件
  • • ①工程目录
    • ②、编写配置文件
• 二、正式代码开发
• • 1、编写各层
  • • ①项目工程目录
    • ②java代码
  • 2、代码测试
  • 小结：
  • 结语：

一、准备工作

开发工具：idea
数据库版本：MySQL8
技术：ssm+mybatisPlus

1、创建表

	CREATE TABLE `emp` (
  `empno` int NOT NULL AUTO_INCREMENT,
  `ename` varchar(10) DEFAULT NULL,
  `job` varchar(9) DEFAULT NULL,
  `mgr` int DEFAULT NULL COMMENT '雇佣的领导编号',
  `hiredate` date DEFAULT NULL COMMENT '雇佣日期',
  `sal` int DEFAULT NULL,
  `comm` int DEFAULT NULL COMMENT '月薪',
  `deptno` int DEFAULT NULL,
  PRIMARY KEY (`empno`),
  KEY `fk_deptno` (`deptno`),
  CONSTRAINT `fk_deptno` FOREIGN KEY (`deptno`) REFERENCES `dept` (`deptno`)
) ENGINE=InnoDB AUTO_INCREMENT=7784 DEFAULT CHARSET=utf8;

2、加入依赖

pom.xml

	<build>
	<!--同步target目录-->
    <resources>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.*</include>
        </includes>
      </resource>
      <resource>
        <directory>src/main/resources</directory>
        <includes>
          <include>**/*.*</include>
        </includes>
      </resource>
    </resources>
  </build>
	<!--spring版本-->
  <properties>
    <spring-version>5.1.6.RELEASE</spring-version>
  </properties>
  <dependencies>
    <!--mysql-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.13</version>
    </dependency>
    <!--spring-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring-version}</version>
    </dependency>
    <!--mybatisPlus-->
    <dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus</artifactId>
      <version>2.3</version>
    </dependency>
    <!--c3p0-->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
    </dependency>
    <!--log4j-->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.12</version>
    </dependency>
    <!-- 支持jstl在jsp的应用 -->
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/taglibs/standard -->
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>
  </dependencies>

3、加入各种配置文件

①工程目录

②、编写配置文件

log4j.properties

加入此文件配置，直接放在resource目录即可，不需要其他地方配置，就能输出日志。（加上很容易找出项目的问题）

log4j.rootLogger=DEBUG, Console 
#Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender 
log4j.appender.Console.layout=org.apache.log4j.PatternLayout 
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n 

log4j.logger.java.sql.ResultSet=INFO 
log4j.logger.org.apache=INFO 
log4j.logger.java.sql.Connection=DEBUG 
log4j.logger.java.sql.Statement=DEBUG 
log4j.logger.java.sql.PreparedStatement=DEBUG 

db.properties

一定注意MySQL8版本数据库得设置时区

jdbc.driver=com.mysql.cj.jdbc.Driver
#连接后面加上设置时区
jdbc.url=jdbc:mysql:///ssm_mp?serverTimezone=UTC
jdbc.user=root
jdbc.password=root

mybatis的核心配置文件：mybati-config.xml

这里的配置是用于控制台输出SQL语句的。其它配置都被放入了spring的核心配置文件统一管理。

<?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="logImpl" value="LOG4J"/>
    </settings>
</configuration>

spring核心配置文件：applicationContext.xml

mybatis的sqlSessionFactory：

    <bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sqlSessionFactory">
        <property name="dataSource" ref="dataSource"/>
        <property name="typeAliasesPackage" value="com.ssm.entity"/>
        <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/>
    </bean>

注意：mybatisPlus最明显的配置改变就是这里：

<bean class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean" id="sqlSessionFactory">
        <property name="dataSource" ref="dataSource"/>
        <property name="typeAliasesPackage" value="com.ssm.entity"/>
        <property name="configLocation" value="classpath:mybatis/mybatis-config.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"
       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
">
    <!--文件引入-->
    <context:property-placeholder location="classpath:db/db.properties"></context:property-placeholder>
    <!--数据源-->
    <bean class="com.mchange.v2.c3p0.ComboPooledDataSource" id="dataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    <!--mybatisPlus的SqlSessionFactoryBean-->
    <bean class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean" id="sqlSessionFactory">
        <property name="dataSource" ref="dataSource"/>
        <!--别名设置-->
        <property name="typeAliasesPackage" value="com.ssm.entity"/>
    	<!--引入mybatis核心配置文件-->
        <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/>
    </bean>
    <!--mapper接口扫描-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
         <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.ssm.mapper"/>
    </bean>
</beans>

springmvc配置文件：

	<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        ">
        <mvc:annotation-driven></mvc:annotation-driven>
        <!--视图解析器-->
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">			
        	<!--设置前缀-->
            <property name="prefix" value="WEB-INF/jsp/"></property>
            <!--设置后缀-->
            <property name="suffix" value=".jsp"></property>
        </bean>
        <!--注解扫描-->
        <context:component-scan base-package="com.ssm.controller"/>
        <context:component-scan base-package="com.ssm.service"/>
</beans>

web.xml

这里有个地方注意下，idea自动生成的是2.4版本，最好改成4.0版本。2.4版本默认不解析jstl的<c:forEach>标签，还需要手动开启

	<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <!--加入spring核心配置文件-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring/applicationContext.xml</param-value>
    </context-param>
    <!--监听器-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <!--配置前端控制器DispatcherServlet-->
    <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:springmvc/springmvc.xml</param-value>
        </init-param>
        <!--启动顺序，值越小越优先-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <!--注意：这里只有两种你写法：1、【/】2、【/.do】
            不能是.*
        -->
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <!--设置字符集过滤器-->
    <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>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

二、正式代码开发

1、编写各层

①项目工程目录

②java代码

实体类：

package com.ssm.entity;

import java.util.Date;

public class Emp {
    private Integer empno;
    private String ename;
    private String job;
    private Integer mgr;
    private Date hiredate;
    private Integer sal;
    private Integer comm;
    private Integer deptno;


    @Override
    public String toString() {
        return "emp{" +
                "empno=" + empno +
                ", ename='" + ename + '\'' +
                ", job='" + job + '\'' +
                ", mgr=" + mgr +
                ", hiredate=" + hiredate +
                ", sal=" + sal +
                ", comm=" + comm +
                ", deptno=" + deptno +
                '}';
    }

    public Integer getEmpno() {
        return empno;
    }

    public void setEmpno(Integer empno) {
        this.empno = empno;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public Integer getMgr() {
        return mgr;
    }

    public void setMgr(Integer mgr) {
        this.mgr = mgr;
    }

    public Date getHiredate() {
        return hiredate;
    }

    public void setHiredate(Date hiredate) {
        this.hiredate = hiredate;
    }

    public Integer getSal() {
        return sal;
    }

    public void setSal(Integer sal) {
        this.sal = sal;
    }

    public Integer getComm() {
        return comm;
    }

    public void setComm(Integer comm) {
        this.comm = comm;
    }

    public Integer getDeptno() {
        return deptno;
    }

    public void setDeptno(Integer deptno) {
        this.deptno = deptno;
    }
}

Mapper类：EmpMapper

这里就只需要继承BaseMapper接口就能得到父类的大量方法

package com.ssm.mapper;

import com.baomidou.mybatisplus.mapper.BaseMapper;
import com.ssm.entity.Emp;

public interface EmpMapper extends BaseMapper<Emp> {

}

Service类：EmpService

package com.ssm.service;

import com.baomidou.mybatisplus.service.IService;
import com.ssm.entity.Emp;

public interface EmpService extends IService<Emp>{

}

Service实现类：EmpServiceImpl

package com.ssm.service.impl;

import com.baomidou.mybatisplus.service.impl.ServiceImpl;
import com.ssm.entity.Emp;
import com.ssm.mapper.EmpMapper;
import com.ssm.service.EmpService;
import org.springframework.stereotype.Service;

@Service
public class EmpServiceImpl   extends ServiceImpl<EmpMapper, Emp> implements EmpService {

}

Controller:EmpController

由于视图解析器设置了前缀和后缀，这里的setViewName方法，就只需要填写jsp文件名称：emplist。（完整路径是：/WEB-INF/jsp/emplist.jsp）

package com.ssm.controller;

import com.ssm.entity.Emp;
import com.ssm.service.EmpService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import javax.annotation.Resource;
import java.util.List;

@Controller
public class EmpController {
    @Autowired
    private EmpService empService;
    @RequestMapping("/findEmpList")
    public ModelAndView findEmpList(){
        List<Emp> empList = empService.selectList(null);
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("empList",empList);
        modelAndView.setViewName("emplist");
        return modelAndView;
    }

}

Jsp视图：emplist.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <table cellpadding="10" cellspacing="0" border="1">
        <tr>
            <td>雇员编号</td>
            <td>雇员姓名</td>
            <td>雇员工作</td>
            <td>雇员领导</td>
            <td>雇佣日期</td>
            <td>雇员月薪</td>
            <td>雇员奖金</td>
            <td>部门编号</td>
        </tr>
        <c:forEach  items="${empList}" var="li">
            <tr>
                <td>${li.empno}</td>
                <td>${li.ename}</td>
                <td>${li.job}</td>
                <td>${li.mgr}</td>
                <td>${li.hiredate}</td>
                <td>${li.sal}</td>
                <td>${li.comm}</td>
                <td>${li.deptno}</td>
            </tr>
        </c:forEach>
    </table>
</body>
</html>

2、代码测试

页面效果：

控制台输出：
通过页面和控制台输出，可以看出测试通过了。

小结：

		   通过观察代码，能够发现mybatisPlus给我们的编码带来了很
		大便利，单表的各种crud方法都是可以直接拿来就用，而我们只
		需要简单的继承和实现框架提供的父类和接口即可。 

结语：

前天笔记本重装系统，我用U盘拷贝了笔记，结果重装系统的时候手残，不小心把U盘格式化了，辛辛苦苦做的笔记没了，所以以后直接把笔记上传到这儿更方便！????

本文地址：https://blog.csdn.net/qq_41936090/article/details/110232235