1、了解Mybatis
MyBatis 是一款优秀的持久层框架,它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息,将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。
本节实例采用封装的Mybatis通用Mapper和Spring整合,演示基本的单表CRUD,复杂的SQL建议自定义
tk-mybatis地址: https://github.com/abel533/Mapper
2、User练习
-
新建db_spring数据库,并在库中新建一个表t_user
-
做好准备工作
添加依赖
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<spring.version>5.1.5.RELEASE</spring.version>
<aspectj.version>1.9.2</aspectj.version>
<junit.version>4.12</junit.version>
<log4j.version>1.2.17</log4j.version>
<slf4j.version>1.7.12</slf4j.version>
<hutool.version>4.5.1</hutool.version>
<mysql.version>5.1.47</mysql.version>
<mybatis.version>3.5.0</mybatis.version>
<mybatis-spring.version>2.0.0</mybatis-spring.version>
<tk-mybatis.version>4.1.5</tk-mybatis.version>
<druid.version>1.1.14</druid.version>
<lombok.version>1.18.6</lombok.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>${aspectj.version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${aspectj.version}</version>
</dependency>
<!--spring-test依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<!--junit依赖-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<!-- log4j日志依赖 -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>${hutool.version}</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.3</version>
</dependency>
<!--spring-context依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<!--spring-jdbc依赖 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>${mybatis.version}</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>${mybatis-spring.version}</version>
</dependency>
<dependency>
<groupId>tk.mybatis</groupId>
<artifactId>mapper</artifactId>
<version>${tk-mybatis.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${druid.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
<scope>provided</scope>
</dependency>
</dependencies>
- 配置文件
<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"
xmlns:tx="http://www.springframework.org/schema/tx"
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
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--读入外部数据库连接属性文件-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!--扫描Service包的组件-->
<context:component-scan base-package="com.spring.orm.service"/>
<!--通过druid配置数据源-->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
init-method="init" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<!-- 初始化大小 -->
<property name="initialSize" value="20"/>
<!-- 连接池最大使用连接数量 -->
<property name="maxActive" value="20"/>
<!-- 连接池最小空闲 -->
<property name="minIdle" value="0"/>
<!-- 配置获取连接等待超时的时间 -->
<property name="maxWait" value="60000"/>
<!-- 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="60000"/>
<!-- 配置一个连接在池中最小生存的时间,单位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="300000"/>
<!-- 连接空闲时测试是否有效 -->
<property name="testWhileIdle" value="false"/>
<!-- 获取连接时测试是否有效 -->
<property name="testOnBorrow" value="false"/>
<!-- 归还连接时是否测试有效 -->
<property name="testOnReturn" value="false"/>
<!-- 打开PSCache缓存,并且指定每个连接上PSCache的大小 -->
<property name="poolPreparedStatements" value="true"/>
<property name="maxPoolPreparedStatementPerConnectionSize" value="20"/>
</bean>
<!-- 配置mybatis的Session -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="typeAliasesPackage" value="com.spring.orm.entity"/>
</bean>
<!-- 配置通用Mapper -->
<bean class="tk.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.spring.orm.dao"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
<property name="markerInterface" value="com.spring.orm.dao.BaseDAO"/>
<property name="properties">
<value>
mappers = com.spring.orm.dao.BaseDAO
IDENTITY = MYSQL
</value>
</property>
</bean>
<!--事务管理bean -->
<bean id="manager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- 使用声明式事务 -->
<tx:annotation-driven transaction-manager="manager"/>
</beans>
- User类
import lombok.Data;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* Created by Administrator on 2019/3/11.
*/
@Table(name="t_user")
@Data
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String account;
private String password;
private Integer credits;
}
- DAO类
import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;
public interface BaseDAO<T> extends Mapper<T>,MySqlMapper<T>{
}
import com.spring.orm.entity.User;
/**
* Created by Administrator on 2019/3/11.
* UserDAO,继承通用DAO接口基础的CRUD功能
*/
public interface UserDAO extends BaseDAO<User> {
}
- Service类
import java.util.List;
/**
* Created by Administrator on 2019/3/11.
*/
public interface UserService {
/**
* 新增用户
*
* @param user
* @return
*/
int insertUser(User user);
/**
* 根据id删除用户
*
* @param id
* @return
*/
int deleteUser(long id);
/**
* 更新用户
*
* @param user
* @return
*/
int updateUser(User user);
/**
* 查询所有用户
*
* @return
*/
List<User> selectUsers();
/**
* 根据id查询用户
*
* @param id
* @return
*/
User getUser(long id);
}
- ServiceImpl类
import com.spring.orm.dao.UserDAO;
import com.spring.orm.entity.User;
import com.spring.orm.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
/**
* Created by Administrator on 2019/3/11.
*/
@Service
@Transactional
public class UserServiceImpl implements UserService {
@Autowired
private UserDAO userDAO;
@Override
public int insertUser(User user) {
return userDAO.insert(user);
}
@Override
public int deleteUser(long id) {
return userDAO.deleteByPrimaryKey(id);
}
@Override
public int updateUser(User user) {
return userDAO.updateByPrimaryKey(user);
}
@Override
public List<User> selectUsers() {
return userDAO.selectAll();
}
@Override
public User getUser(long id) {
return userDAO.selectByPrimaryKey(id);
}
}
- Test类
import com.spring.orm.entity.User;
import com.spring.orm.service.UserService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.List;
import static org.junit.Assert.*;
/**
* Created by Administrator on 2019/3/11.
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/spring_mybatis.xml"})
public class UserServiceImplTest {
@Autowired
private UserService userService;
@Test
public void insertUser() throws Exception {
User user=new User();
user.setAccount("test");
user.setPassword("88888888");
user.setCredits(999);
int n=userService.insertUser(user);
assertEquals(1,n);
}
@Test
public void deleteUser() throws Exception {
int n=userService.deleteUser(2);
assertEquals(1,n);
}
@Test
public void updateUser() throws Exception {
User user=userService.getUser(3);
user.setPassword("000000");
user.setCredits(11111);
int n=userService.updateUser(user);
assertEquals(1,n);
}
@Test
public void selectUsers() throws Exception {
List<User> user=userService.selectUsers();
user.forEach(user1 -> System.out.println(user));
}
@Test
public void getUser() throws Exception {
User user=userService.getUser(1);
System.out.println(user);
}
}