第一步:創建Maven項目
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<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>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.4</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
第二步:創建log4j.properties
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
第三步:MySQL配置文件
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1/db_test?useSSL=false&serverTimezone=CST
username=root
password=root
第四步:MyBatis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>
<!--引入外部properties文件 -->
<properties resource="mysql.properties"></properties>
<settings>
<!-- 打印查詢語句 -->
<setting name="logImpl" value="STDOUT_LOGGING" />
</settings>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED"> <!-- 數據源的配置,連接到數據庫 -->
<property name="driver" value="${driver}" />
<property name="url" value="${url}"/>
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper class="com.hc.mapper.EmpDao"/>
</mappers>
</configuration>
注意:定義mapper時使用的class
第五步:實體類
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Emp implements Serializable {
private Integer empno;
private String ename;
private String job;
private Integer mgr;
private Date hiredate;
private double sal;
private double comm;
private int deptno;
}
第六步:EmpDao
public interface EmpDao {
@Insert("insert into tb_emp(empno,ename,job,mgr,hiredate,sal,comm,deptno) values(#{empno},#{ename},#{job},#{mgr},#{hiredate},#{sal},#{comm},#{deptno});")
public void addEmp(Emp emp);
@Delete("delete from tb_emp where empno=#{empno};")
public void deleteEmpById(int empno);
@Update("update tb_emp set ename=#{ename},job=#{job},mgr=#{mgr},hiredate=#{hiredate},sal=#{sal},comm=#{comm},deptno=#{deptno} where empno=#{empno};")
public void updateEmp(Emp emp);
@Select("Select * from tb_emp where empno=#{empno}")
public Emp findEmpById(int empno);
@Select("select * from tb_emp")
public List<Emp> findAllEmps();
}
第七步:工具類MyBatisUtil
public class MyBatisUtil {
private static String CONFIG_FILE_LOCATION = "mybatis-config.xml";
private static final ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();
private static SqlSessionFactory sessionFactory;
static {
try {
Reader reader = Resources.getResourceAsReader(CONFIG_FILE_LOCATION);
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
sessionFactory = builder.build(reader);
} catch (Exception e) {
e.printStackTrace();
}
}
public static SqlSession getSession() {
SqlSession session = threadLocal.get();
if (session == null) {
session = (sessionFactory != null) ? sessionFactory.openSession() : null;
threadLocal.set(session);
}
return session;
}
public static void closeSession() {
SqlSession session = threadLocal.get();
if (session != null) {
session.close();
threadLocal.set(null);
}
}
}
第八步:測試代碼
public class EmpDaoTest {
@Test
public void addEmp() {
Emp emp = new Emp(123, "123", "123", 7788, new Date(), 123d, 123d, 20);
SqlSession session = null;
try {
session = MyBatisUtil.getSession();
EmpDao mapper = session.getMapper(EmpDao.class);
mapper.addEmp(emp);
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
MyBatisUtil.closeSession();
}
}
@Test
public void deleteEmpById() {
int empno = 123;
SqlSession session = null;
try {
session = MyBatisUtil.getSession();
EmpDao mapper = session.getMapper(EmpDao.class);
mapper.deleteEmpById(empno);
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
MyBatisUtil.closeSession();
}
}
@Test
public void updateEmp() {
Emp emp = new Emp(123, "aaa", "aaa", 7788, new Date(), 123d, 123d, 20);
SqlSession session = null;
try {
session = MyBatisUtil.getSession();
EmpDao mapper = session.getMapper(EmpDao.class);
mapper.updateEmp(emp);
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
MyBatisUtil.closeSession();
}
}
@Test
public void findEmpById() {
int empno = 123;
Emp emp = null;
SqlSession session = null;
try {
session = MyBatisUtil.getSession();
EmpDao mapper = session.getMapper(EmpDao.class);
emp = mapper.findEmpById(empno);
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
MyBatisUtil.closeSession();
}
System.out.println(emp);
}
@Test
public void findAllEmps() {
List<Emp> res = null;
SqlSession session = null;
try {
session = MyBatisUtil.getSession();
EmpDao mapper = session.getMapper(EmpDao.class);
res = mapper.findAllEmps();
session.commit();
} catch (Exception e) {
session.rollback();
e.printStackTrace();
} finally {
MyBatisUtil.closeSession();
}
for (Emp emp : res) {
System.out.println(emp);
}
}
}