Mybatis所需要的jar包：
需要引用两个jar包，一个是mybatis，另一个是MySQL-connector-Java，如果是maven工程的话，pom里如下添加依赖就可以了。
<dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.3</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.26</version> </dependency>
数据准备：
在MySQL中造点数据进行测试用：
CREATE DATABASE mybatis_test; CREATE TABLE user ( age INTEGER NOT NULL, name VARCHAR(64) NOT NULL DEFAULT '' ); insert user values(18,'zhanjindong'); insert user values(20,'zhangsan');
配置文件：
需要两类配置文件，一类是MyBatis的配置文件mybatis-config.xml，示例中是一个很简单配置，详细的配置网上有很多说明。
<?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>
<settings>
<!-- changes from the defaults for testing -->
<setting name="cacheEnabled" value="false" />
<setting name="useGeneratedKeys" value="true" />
<setting name="defaultExecutorType" value="REUSE" />
</settings>
<typeAliases>
<typeAlias alias="User" type="test.mybatis.User"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="jdbc"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://192.168.71.38:3306/mybatis_test"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mappers/UserMapper.xml" />
</mappers>
</configuration>
另一类是数据访问接口映射文件：示例中是UserMapper.xml。这个文件一般放在src/main/resource下面或子目录下mybatis就可以找到了，在mybatis-config.xml中由mappers/mapper节点的resource指定。
<?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="test.mybatis.UserMapper">
<!-- 这里namespace必须是UserMapper接口的路径” -->
<insert id="insertUser" parameterType="User">
insert into user(name,age) values(#{name},#{age})
<!-- 这里sql结尾不能加分号，否则报“ORA-00911”的错误 -->
</insert>
<!-- 这里的id必须和UserMapper接口中的接口方法名相同 -->
<select id="getUser" resultType="User" parameterType="java.lang.String">
select * from user where name=#{name}
</select>
</mapper>
对应这个映射文件就是test.mybatis这个命名空间下的UserMapper这个接口，只是定义了访问数据表的接口：
package test.mybatis;
public interface UserMapper {
public void insertUser(User user);
public User getUser(String name);
}
需要一个POJO:User.java
package test.mybatis;
public class User {
private String name;
private Integer age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public User(String name, Integer age) {
super();
this.name = name;
this.age = age;
}
public User() {
super();
}
}
测试：
通过MyBatis操作数据库用到的是一个叫SqlSession的类，这个类是通过SqlSessionFactory产生的，一般建议在全局维护一个SqlSessionFactory就可以了。
TestMyBatis.java
package test.mybatis;
import java.io.IOException;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class MyBatisUtil {
private final static SqlSessionFactory sqlSessionFactory;
static {
String resource = "mybatis-config.xml";
Reader reader = null;
try {
reader = Resources.getResourceAsReader(resource);
} catch (IOException e) {
System.out.println(e.getMessage());
}
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
}
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}
测试代码如下：
TestMyBatis.java
package test.mybatis;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
public class TestMyBatis {
static SqlSessionFactory sqlSessionFactory = null;
static {
sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
}
public static void main(String[] args) {
testAdd();
getUser();
}
public static void testAdd() {
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = new User("lisi", new Integer(25));
userMapper.insertUser(user);
sqlSession.commit();// 这里一定要提交，不然数据进不去数据库中
} finally {
sqlSession.close();
}
}
public static void getUser() {
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.getUser("zhangsan");
System.out.println("name: " + user.getName() + "|age: "
+ user.getAge());
} finally {
sqlSession.close();
}
}
}
1、mybatis会用log4j记录日志，但是开启debug模式貌似对性能影响非常厉害。
2、mybatis的查询缓存对性能的影响非常大，启用和不启用差距非常大
以上所述是小编给大家介绍的Mybatis的详细使用教程，希望对大家有所帮助，如果大家有任何疑问欢迎给我留言，小编会及时回复大家的！
