本文介绍了两种在Mybatis中批量插入数据的方法：一种是使用foreach标签进行批量操作，另一种是利用ExecutorType.BATCH执行批处理。通过具体的实体类Teacher、DAO接口、配置文件以及工具类的设置，详细阐述了这两种方式的实现过程，旨在提高数据库操作效率。
Mybatis批量插入数据到数据库
常规方式(foreach)批量插入
数据库里的Teacher表有如下字段：id，tname,age。
创建与数据库表对应的实体类Teacher.java
package com.lanou3g.mybatis.bean;
import lombok.Getter;
import lombok.Setter;
import java.util.List;
@Getter
@Setter
public class Teacher {
private Integer id;
private String tname;
private Integer age;
public Teacher (){}
public Teacher(String tname) {
this.tname = tname;
}
@Override
public String toString() {
return "{" +
"id:" + id +
", tname:'" + tname + '\'' +
", age:'" + age + '\'' +
"]}\n";
}
}
dao层接口TeacherDao
package com.lanou3g.mybatis.dao;
import com.lanou3g.mybatis.bean.Teacher;
import java.util.List;
public interface TeacherDao {
int batchInsertByNormal(List<Teacher> teacherList);
}
数据库相关外部配置文件jdbc.properties
jdbc.url=jdbc:mysql://localhost:3306/yanfa5?characterEncoding=utf8
jdbc.driver=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=root
Mybatis的全局配置文件mybatis_conf.xml
主要用于配置Mybatis的运行环境（事务管理器、数据源等）。
<?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>
<!-- 引入外部的properties文件，只能引入一个 -->
<properties resource="jdbc.properties" />
<settings>
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<!-- 定义类型别名（全局），在所有的Mapper.xml中都可以用 -->
<typeAliases>
<typeAlias type="com.lanou3g.mybatis.bean.Teacher" alias="Teacher" />
</typeAliases>
<!-- 配置多套环境的数据库连接参数（如：开发环境、生产环境） -->
<environments default="yanfa5">
<environment id="yanfa5">
<!-- 事务管理器：
MANAGED: 这个配置就是告诉mybatis不要干预事务，具体行为依赖于容器本身的事务处理逻辑。
JDBC: 这个配置就是直接使用了 JDBC 的提交和回滚设置，它依赖于从数据源得到的连接来管理事务作用域。
-->
<transactionManager type="MANAGED"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.user}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mapper/TeacherMapper.xml" />
</mappers>
</configuration>
SQL配置文件TeacherMapper.xml
<?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">
<!-- namespace对应空Dao接口的全名 -->
<mapper namespace="com.lanou3g.mybatis.dao.TeacherDao">
<resultMap id="teacher" type="Teacher">
<id column="t_id" property="id" />
<result column="tname" property="tname" />
<result column="age" property="age" />
</resultMap>
<!-- 常规方式批量插入 -->
<insert id="batchInsertByNormal" parameterType="Teacher">
insert into teacher (tname, age) values
<!--open属性表示在拼接的SQL语句前加"xx",separator属性表示在拼接的SQL语句之间加"xx"，close属性表示在拼接的SQL语句后加"xx"-->
<foreach collection="list" item="teacher" separator="," close=";">
(#{teacher.tname}, #{teacher.age})
</foreach>
</insert>
</mapper>
工具类MyBatisTools.java
封装Mybatis初始化操作
package com.lanou3g.mybatis;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.BatchResult;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.InputStream;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
/**
* 封装Mybatis初始化操作
* 支持创建多env sqlSessionFactory
* 整个应用生命周期内相同env的sqlSessionFactory对象只有一个
*/
@Slf4j
public class MyBatisTools {
private static ConcurrentHashMap<String, SqlSessionFactory> factoryMap = new MyConcurrentHashMap();
private static MyBatisTools myBatisTools;
private MyBatisTools() {}
public static MyBatisTools getInstance() {
if(myBatisTools == null) {
synchronized (MyBatisTools.class) {
if(myBatisTools == null) {
myBatisTools = new MyBatisTools();
}
}
}
log.debug("当前一共有: " + factoryMap.size() +"个SqlSessionFactory实例");
log.debug("他们分别是: " + factoryMap);
return myBatisTools;
}
public SqlSessionFactory getSessionFactory() {
return getSessionFactory(null);
}
public SqlSessionFactory getSessionFactory(String env) {
try {
// 1. 读入配置文件
InputStream in = Resources.getResourceAsStream("mybatis_conf.xml");
// 2. 构建SqlSessionFactory(用于获取sqlSession)
SqlSessionFactory sessionFactory = null;
synchronized (factoryMap) {
if(factoryMap.containsKey(env)) {
return factoryMap.get(env);
} else {
sessionFactory = new SqlSessionFactoryBuilder().build(in, env);
factoryMap.put(env, sessionFactory);
}
}
return sessionFactory;
} catch (Exception e) {
log.error("初始化SqlSessionFactory失败", e);
return null;
}
}
public SqlSession openSession() {
return getSessionFactory(null).openSession();
}
public SqlSession openSession(boolean autoCommit) {
return getSessionFactory(null).openSession(autoCommit);
}
public SqlSession openSession(ExecutorType executorType, boolean autoCommit) {
return getSessionFactory(null).openSession(executorType, autoCommit);
}
public static int flushStatement(SqlSession sqlSession) {
int effectRows = 0;
List<BatchResult> batchResults = sqlSession.flushStatements();
if(batchResults == null || batchResults.size() < 1) {
return effectRows;
}
int[] effectArr = batchResults.get(0).getUpdateCounts();
for(int effectRow : effectArr) {
effectRows += effectRow;
}
return effectRows;
}
}
/**
* 继承原生ConcurrentHashMap，处理null key问题
*/
class MyConcurrentHashMap extends ConcurrentHashMap {
@Override
public Object put(Object key, Object value) {
if(key == null) {
key = "null";
}
return super.put(key, value);
}
@Override
public boolean containsKey(Object key) {
if(key == null) {
key = "null";
}
return super.containsKey(key);
}
@Override
public Object get(Object key) {
if(key == null) {
key = "null";
}
return super.get(key);
}
}
入口类AppTest.java
@Slf4j
public class AppTest {
TeacherDao teacherDao = null;
List<Teacher> testData = new ArrayList<>();
String[] tnameArr = new String[]{"四火", "四水", "四金", "四木", "四土"};
<!--@Before注解表示下面的test单元测试在执行之前都会先执行添加@Before注解的方法-->
@Before
public void setUp() {
teacherDao = MyBatisTools.getInstance().openSession().getMapper(TeacherDao.class);
Random random = new Random();
// 构造测试数据
for(int i = 0; i < 10000; i++) {
Teacher teacher = new Teacher();
int idx = random.nextInt(tnameArr.length);
teacher.setTname(tnameArr[idx] +"_"+ (i + 1));
teacher.setAge(i+1);
testData.add(teacher);
}
}
/**
* 常规批量插入。（通过foreach，生成很长的SQL）
*/
@Test
public void testBatchInsertByNormal() {
long start = System.currentTimeMillis();
int rows = teacherDao.batchInsertByNormal(testData);
log.info("插入数据行数： " + rows+", 耗时： " + (System.currentTimeMillis() - start));
}
}
使用ExecutorType.BATCH方式执行批量操作
创建与数据库表对应的实体类Teacher.java(与foreach方式批量插入的实体类相同)
dao层接口TeacherDao
package com.lanou3g.mybatis.dao;
import com.lanou3g.mybatis.bean.Teacher;
import java.util.List;
public interface TeacherDao {
int insertTeacher(Teacher teacher);
}
数据库相关外部配置文件jdbc.properties(与foreach方式批量插入的配置文件相同)
Mybatis的全局配置文件mybatis_conf.xml(与foreach方式批量插入的配置文件相同)
主要用于配置Mybatis的运行环境（事务管理器、数据源等）。
SQL配置文件TeacherMapper.xml
<?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">
<!-- namespace对应空Dao接口的全名 -->
<mapper namespace="com.lanou3g.mybatis.dao.TeacherDao">
<resultMap id="teacher" type="Teacher">
<id column="t_id" property="id" />
<result column="tname" property="tname" />
<result column="age" property="age" />
</resultMap>
<insert id="insertTeacher" parameterType="Teacher">
insert into teacher(tname,age) values (#{tname},#{age});
</insert>
</mapper>
工具类MyBatisTools.java(与foreach方式批量插入的工具类相同)
作用：封装Mybatis初始化操作
入口类AppTest.java
@Slf4j
public class AppTest {
TeacherDao teacherDao = null;
List<Teacher> testData = new ArrayList<>();
String[] tnameArr = new String[]{"四火", "四水", "四金", "四木", "四土"};
@Before
public void setUp() {
teacherDao = MyBatisTools.getInstance().openSession().getMapper(TeacherDao.class);
Random random = new Random();
// 构造测试数据
for(int i = 0; i < 10000; i++) {
Teacher teacher = new Teacher();
int idx = random.nextInt(tnameArr.length);
teacher.setTname(tnameArr[idx] +"_"+ (i + 1));
teacher.setAge(i+1);
testData.add(teacher);
}
}
/**
* 使用ExecutorType.BATCH方式执行批量操作
*/
@Test
public void testBatchInsertByExecutorType() {
SqlSessionFactory factory = MyBatisTools.getInstance().getSessionFactory();
SqlSession sqlSession = factory.openSession(ExecutorType.BATCH, false);
TeacherDao teacherDao = sqlSession.getMapper(TeacherDao.class);
long start = System.currentTimeMillis();
int rows = 0;
int batchSize = 100;
int count = 0;
for(Teacher teacher : testData) {
teacherDao.insertTeacher(teacher);
count ++;
if(count % batchSize == 0) {
rows+=MyBatisTools.flushStatement(sqlSession);
}
}
sqlSession.flushStatements();
sqlSession.commit();
sqlSession.close();
log.info("插入数据行数： " + rows+", 耗时： " + (System.currentTimeMillis() - start));
}
}
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