SSM（Spring+SpringMVC+MyBatis）框架集由Spring、MyBatis两个开源框架整合而成.为了加深记忆学习,也为了后续资源方便使用.所以决定就对SSM做一个整合,首先是Mybatis层。

思路：

1.开发环境

基本环境：

IDEA
MySQL 8.0.22
Tomcat 9
Maven 3.6

2.数据库环境

创建一个存放书籍数据的数据库表

CREATE DATABASE `ssmbuild`;USE `ssmbuild`;DROP TABLE IF EXISTS `books`;CREATE TABLE `books` (
`bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` VARCHAR(100) NOT NULL COMMENT '书名',
`bookCounts` INT(11) NOT NULL COMMENT '数量',
`detail` VARCHAR(200) NOT NULL COMMENT '描述',
KEY `bookID` (`bookID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8INSERT  INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES
(1,'Java',1,'Java核心技术卷'),
(2,'MySQL',10,'MySQL入门到跑路'),
(3,'Linux',5,'Linux实用教程');

3.基本环境搭建

1、新建一Maven项目--->ssmbuild ，添加web的支持

2、导入相关的pom依赖.

常用的依赖也就是：Junit，数据库驱动，数据库连接池，Servlet ， JSP，Mybatis，Spring


<dependencies><!--Junit--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><!--数据库驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.22</version></dependency><!-- 数据库连接池 --><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency><!--Servlet - JSP --><dependency><groupId>javax.servlet</groupId><artifactId>servlet-api</artifactId><version>2.5</version></dependency><dependency><groupId>javax.servlet.jsp</groupId><artifactId>jsp-api</artifactId><version>2.2</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>jstl</artifactId><version>1.2</version></dependency><!--Mybatis--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.2</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.2</version></dependency><!--Spring--><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.1.9.RELEASE</version></dependency>
</dependencies>

tips:如果mybatis用的是3.5以上的，spring用的5.0以上的，mybatis-spring必须使用2.0以上版本

3、Maven资源过滤设置


<build><resources><resource><directory>src/main/java</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource><resource><directory>src/main/resources</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource></resources>
</build>

4、IDEA连接数据库

这里提及一下如若有报serverTimezone错误的，这是因为MySQL在8.0以上，所导致的时区错误。直接在在Advanced中将serverTimezone设置成Hongkong即可。

然后再Schemas下选择数据库ssmbuild，点击应用!做完这些基本准备工作。

4.建包和配置框架

com.kuang.pojo(实体类)
com.kuang.dao（数据访问层）
com.kuang.service（业务层）
com.kuang.controller（控制层）
mybatis-config.xml（这是mybatis核心配置文件）


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration></configuration>

applicationContext.xml（这是spring核心配置文件）


<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd"></beans>

5.Mybatis层编写

1、在resource下新建数据库配置文件 database.properties（用来关联数据库）


jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=123456

2、编写MyBatis的核心配置文件


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><typeAliases><package name="com.orange.pojo"/></typeAliases><mappers><mapper resource="com/orange/dao/BookMapper.xml"/></mappers></configuration>

3、编写数据库对应的实体类 com.orange.pojo.Books


package com.orange.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {//这里的变量应和数据库保持一致private int bookID;private String bookName;private int bookCounts;private String detail;}

(这里为了方便也是使用到了注解，lombok插件，当然也可以选择不用)

导入依赖:


<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.16.0</version>
</dependency>

4、编写Dao层的 Mapper接口！


import java.util.List;public interface BookMapper {//增加一个Bookint addBook(Books book);//根据id删除一个Bookint deleteBookById(int id);//更新Bookint updateBook(Books books);//根据id查询,返回一个BookBooks queryBookById(int id);//查询全部Book,返回list集合List<Books> queryAllBook();}

5、编写接口对应的 Mapper.xml 文件。(需要导入MyBatis的包)

一个Mapper对应一个接口


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.orange.dao.BookMapper"><!--增加一个Book--><insert id="addBook" parameterType="Books">insert into ssmbuild.books(bookName,bookCounts,detail)values (#{bookName}, #{bookCounts}, #{detail})</insert><!--根据id删除一个Book--><delete id="deleteBookById" parameterType="int">delete from ssmbuild.books where bookID=#{bookID}</delete><!--更新Book--><update id="updateBook" parameterType="Books">update ssmbuild.booksset bookName = #{bookName},bookCounts = #{bookCounts},detail = #{detail}where bookID = #{bookID}</update><!--根据id查询,返回一个Book--><select id="queryBookById" resultType="Books">select * from ssmbuild.bookswhere bookID = #{bookID}</select><!--查询全部Book--><select id="queryAllBook" resultType="Books">SELECT * from ssmbuild.books</select></mapper>

6、编写Service层的接口和实现类

BookService接口


package com.orange.service;
import com.orange.pojo.Books;import java.util.List;//BookService:底下需要去实现,调用dao层
public interface BookService {//增加一个Bookint addBook(Books book);//根据id删除一个Bookint deleteBookById(int id);//更新Bookint updateBook(Books books);//根据id查询,返回一个BookBooks queryBookById(int id);//查询全部Book,返回list集合List<Books> queryAllBook();
}

再去写它的实现类BookServiceImpl


package com.orange.service;import com.orange.dao.BookMapper;
import com.orange.pojo.Books;import java.util.List;public class BookServiceImpl implements BookService {//调用dao层的操作，设置一个set接口，方便Spring管理private BookMapper bookMapper;public void setBookMapper(BookMapper bookMapper) {this.bookMapper = bookMapper;}public int addBook(Books book) {return bookMapper.addBook(book);}public int deleteBookById(int id) {return bookMapper.deleteBookById(id);}public int updateBook(Books books) {return bookMapper.updateBook(books);}public Books queryBookById(int id) {return bookMapper.queryBookById(id);}public List<Books> queryAllBook() {return bookMapper.queryAllBook();}
}

Mybatis部分整合完毕!在学习过程中总结的并加上一些容易遇到的错误,后续跟进Spring整合Mybatis~