Mybatis在持久层的一些配置及操作
作者:互联网
一.在一个web项目里建立多个模块,多模块项目的初步了解
- 从maven原型搭建项目
- 父项目pom.xml的配置
- 子模块的Dao层的Mybatis的使用
1.解析pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<!--版本号-->
<modelVersion>4.0.0</modelVersion>
<!--唯一项目ID-->
<groupId>org.example</groupId>
<artifactId>mybatis</artifactId>
<packaging>pom</packaging>
<version>1.0-SNAPSHOT</version>
<!--子模块-->
<modules>
<module>demo01</module>
</modules>
<properties>
<maven.compiler.source>15</maven.compiler.source>
<maven.compiler.target>15</maven.compiler.target>
</properties>
<!--项目依赖-->
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.12</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.25</version>
<scope>compile</scope>
</dependency>
</dependencies>
<!--解决无法读取java包中资源的问题-->
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
2.子模块pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<!--继承父类依赖-->
<parent>
<artifactId>mybatis</artifactId>
<groupId>org.example</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>demo01</artifactId>
<dependencies>
<dependency>
<groupId>io.ktor</groupId>
<artifactId>ktor-utils-jvm</artifactId>
<version>1.3.1</version>
</dependency>
</dependencies>
<properties>
<maven.compiler.source>15</maven.compiler.source>
<maven.compiler.target>15</maven.compiler.target>
</properties>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
3.mybatis-config.xml 的配置
<?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>
<!--dafault可以换成别的,环境可以配置多个,主要用于切换数据库-->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<!--数据库连接池-->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false "/>
<property name="username" value="root"/>
<property name="password" value="1234"/>
</dataSource>
</environment>
</environments>
<!--需要写出配置中所有的Mapper全类名,一定要用"/"分隔-->
<mappers>
<mapper resource="com/demo/dao/UserMapper.xml"/>
</mappers>
</configuration>
这个配置相当于JDBC中的获取驱动后链接数据库获取Connection
4.子模块的Dao层的Mybatis的使用
- 构建dao接口操作数据业务
public interface UserMapper {
//查询全部用户
List<User> getUserList();
//根据id查询用户
User getUserById(int id);
//插入用户
void addUser(User user);
//修改用户
void upDateUser(Map<String,Object> map);
//删除用户
void deleteUser(int id);
}
- 建立对应的Mapper.xml配置文件
<?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">
<!--命名空间填对应的接口全类名-->
<mapper namespace="com.demo.dao.UserMapper">
<!--id表示对应接口中定义的方法,resultType表示对应Mapper操纵sql所产生的结果集类型-->
<select id="getUserList" resultType="com.demo.pojo.User">
select * from mybatis.user;
</select>
<!--parameterType表示需要传入参数的类型,映射到接口方法的参数,类似于JDBC中的通配符--->
<select id="getUserById" resultType="com.demo.pojo.User" parameterType="int">
select * from mybatis.user where id = #{id};
</select>
<insert id="addUser" parameterType="com.demo.pojo.User">
insert into mybatis.user(id, name, pwd) VALUES (#{id},#{name},#{pwd});
</insert>
<update id="upDateUser" parameterType="Map">
update mybatis.user set name=#{userName},pwd=#{password} where id=#{id};
</update>
<delete id="deleteUser" parameterType="int">
delete from mybatis.user where id=#{id};
</delete>
</mapper>
注意 在模糊查询中如
select * from Table where name like "%#{S}%"
模糊查询 name中含有S的行
- 获取sqlSession的标准化方法
package com.demo.Utils;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
//因为只启动一次所以放在静态块里
static {
InputStream resourceAsStream = null;
try {
//从config XML文件中获取SqlSessionFactory
String resource = "mybatis-config.xml";
resourceAsStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (resourceAsStream != null) {
resourceAsStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (resourceAsStream != null) {
resourceAsStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
}
标签:xml,持久,配置,mybatis,resourceAsStream,import,Mybatis,org,id 来源: https://blog.csdn.net/weixin_51060912/article/details/121365286