---Mybatis3学习笔记(2)

1.先来一个最简单的mybatis操作MySql数据库的例子

　　

//(1)定义一个实体类(com.ggzhang.mybatis.pojo.Student)
package com.ggzhang.mybatis.pojo;public class Student {private Integer id; private String name; private int age; private double score; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public double getScore() { return score; } public void setScore(double score) { this.score = score; } @Override public String toString() { return "Student [id=" + id + ", name=" + name + ", age=" + age + ", score=" + score + "]"; } public Student() { super(); // TODO Auto-generated constructor stub } public Student(Integer id, String name, int age, double score) { super(); this.id = id; this.name = name; this.age = age; this.score = score; } }

生成一个简单的表Student

SET FOREIGN_KEY_CHECKS=0; -- ---------------------------- -- Table structure for `student` -- ---------------------------- DROP TABLE IF EXISTS `student`; CREATE TABLE `student` (`id` int(5) NOT NULL, `name` varchar(20) DEFAULT NULL, `age` int(3) DEFAULT NULL, `score` double DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; 1 package com.ggzhang.mybatis.dao; 2 3 import com.ggzhang.mybatis.pojo.Student; 4 5 /** 6 * 定义dao接口 7 * 8 * @author zhang 9 * 10 */ 11 public interface StudentDao { 12 void insertStudent(Student student); 13 }

定义映射文件:注意:#{}中写入的是Student类的属性名.对于paramterType属性,框架会自定根据用户执行的SqlSession方法中的参数自动检测到,所以也可以不用指定parameterType属性

<?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.ggzhang.myabtis.dao.StudentDao"> <insert id="insertStudent" parameterType="com.ggzhang.mybatis.pojo.Student"> insert into student(id,name,age,score) values(#{id},#{name},#{age},#{score}) </insert> </mapper>

定义主配置文件.mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!-- 主配置文件: 1)数据库连接信息, 事务配置; 2)加载映射文件 --> <!-- 默认使用的环境信息 --> <environments default="developer"> <!-- 开发环境 --> <environment id="developer"> <!-- 事务管理: type:事务类型 JDBC:使用的Connection的事务管理 commit, rollback MANAGED: 由容器管理事务(Spring是容器) --> <transactionManager type="JDBC" /> <!-- 数据源 type:数据源类型 POOLED : 使用数据库连接池 UNPOOLED: 不使用数据库的连接池. 每次操作的创建连接, 使用完毕后关闭连接. JNDI: 外部数据源 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatistest"/> <property name="username" value="root"/> <property name="password" value="root"/> </dataSource> </environment> <!-- 线上环境 --> <environment id="online"> <!-- 事务管理: type:事务类型 JDBC:使用的Connection的事务管理 commit, rollback MANAGED: 由容器管理事务(Spring是容器) --> <transactionManager type="JDBC" /> <!-- 数据源配置 type:数据源类型 POOLED : 使用数据库连接池 UNPOOLED: 不使用数据库的连接池. 每次操作的创建连接, 使用完毕后关闭连接. JDNI: 外部数据源 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatistest"/> <property name="username" value="root"/> <property name="password" value="root"/> </dataSource> </environment> </environments> <!-- 加载sql映射文件 --> <mappers> <mapper resource="com/ggzhang/mybatis/dao/StudentDao.xml"/> <!-- <mapper url="file:///d:/studentMapper.xml" /> --> </mappers> </configuration>

定义Dao实现类

package com.ggzhang.mybatis.dao;import java.io.IOException; import java.io.InputStream; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import com.ggzhang.mybatis.pojo.Student; public class StudentDaoImpl implements StudentDao { private SqlSession session; @Override public void insertStudent(Student student) { try { // 读取配置文件 InputStream inputStream = Resources .getResourceAsStream("mybatis-config.xml"); // 创建SqlSessionFactory SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder() .build(inputStream); // 创建SqlSession对象 session = sqlSessionFactory.openSession(); session.insert("insertStudent", student); // 提交 session.commit(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if (session != null) { session.close(); } } } }

定义测试类

package com.ggzhang.mybatis.test;import org.junit.Test;import com.ggzhang.mybatis.dao.StudentDao; import com.ggzhang.mybatis.dao.StudentDaoImpl; import com.ggzhang.mybatis.pojo.Student; public class MybatisTest { @Test public void testInsert(){ StudentDao studentDao = new StudentDaoImpl(); Student student = new Student(3,"赵六",26,96.5); studentDao.insertStudent(student); } }

就可以成功的插入数据了,底下是log4j打印出来的信息.包括生成的Sql,

DEBUG [main] - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter. DEBUG [main] - PooledDataSource forcefully closed/removed all connections. DEBUG [main] - PooledDataSource forcefully closed/removed all connections. DEBUG [main] - PooledDataSource forcefully closed/removed all connections. DEBUG [main] - PooledDataSource forcefully closed/removed all connections. DEBUG [main] - Opening JDBC Connection DEBUG [main] - Created connection 1189752912. DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@46ea3050] DEBUG [main] - ==> Preparing: insert into student(id,name,age,score) values(?,?,?,?) DEBUG [main] - ==> Parameters: 3(Integer), 赵六(String), 26(Integer), 96.5(Double) DEBUG [main] - <== Updates: 1 DEBUG [main] - Committing JDBC Connection [com.mysql.jdbc.JDBC4Connection@46ea3050] DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@46ea3050] DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@46ea3050] DEBUG [main] - Returned connection 1189752912 to pool.

 

转载于:https://www.cnblogs.com/ggzhangblog/p/6399510.html

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