MyBatis——第一个程序
MyBatis1:初识
MyBatis第一个程序
流程:搭建环境–》导入MyBatis–》编写代码–》测试
1、创建一张User表。
关键字id、username、pwd
2、导入相关jar包
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.23</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.6</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
</dependency>
</dependencies>
3、编写MyBatis核心配置文件
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?userSSL=true&useUnicode=true&characterEncoding=UTF8&serverTimezone=GMT"/>
<property name="username" value="root"/>
<property name="password" value="Su190419.."/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="UserMapper.xml"/>
</mappers>
</configuration>
4、编写工具类
public class MyBatiUtil {
private static SqlSessionFactory sqlSessionFactory;
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
static{
String resource = "mybatis-config.xml";
try {
InputStream resourceAsStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
} catch (IOException e) {
e.printStackTrace();
}
}
}
5、实体类
package com.pp.pojo;
@Data
public class User {
private int id;
private String name;
private String pwd;
}
6、编写Mapper(DAO)接口类
public interface UserDao {
List<User> getUserLike(String value);
List<User> getUserList();
User getUserById(int id);
int addUser(User user);
int updateUser(User user);
int deleteUser(int id);
}
7、编写Mapper.xml配置文件
namespace十分重要,不能写错
<?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.pp.dao.UserDao">
<select id="getUserLike" resultType="com.pp.pojo.User">
select * from mybatis.user where name like #{value}
</select>
</mapper>
8、编写测试类
- Junit包测试
public class MyTest {
@Test
public void selectUser() {
SqlSession session = MybatisUtils.getSession();
//方法一:
//List<User> users = session.selectList("com.kuang.mapper.UserMapper.selectUser");
//方法二:
UserMapper mapper = session.getMapper(UserMapper.class);
List<User> users = mapper.selectUser();
for (User user: users){
System.out.println(user);
}
session.close();
}
}
9、db.properties
driver = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3306/mybatis?userSSL=true&useUnicode=true&characterEncoding=UTF8&serverTimezone=GMT
username = root
password = Su190419..
10、log4j.properties
#将等级为DEBUG的日志信息输出到console和file这两个目的地,console和file的定义在下面的代码
log4j.rootLogger = DEBUG,console ,file
#控制台输出的相关设置
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.Threshold = DEBUG
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern = [%c]-%m%n
#文件输出的相关设置
log4j.appender.file = org.apache.log4j.RollingFileAppender
log4j.appender.file.File = ./log/pp.log
log4j.appender.file.MaxFileSize = 10mb
log4j.appender.file.Threshold = DEBUG
log4j.appender.file.layout = org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern = [%p][%d{yy-MM-dd}][%c]%m%n
#日志输出级别
log4j.logger.org.mybatis=DEBUG
log4j.logger.java.sql=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.ResultSet=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG
posted on 2021-04-05 22:23 JavaCoderPan 阅读(7) 评论(0) 编辑 收藏 举报 来源