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本文适用于mybatis框架初学者,能够经过这个小例子,初识mybatis的简单易用.java
建立一个java工程或者web工程均可以,而后导入mybatis的jar包和依赖包还有数据库的jar包,本人使用Oracle10g数据库 mybatis-3.2.2.jar 核心驱动 asm-3.3.1.jar cglib-2.2.2.jar commons-logging-1.1.1.jar javassist-3.17.1-GA.jar log4j-1.2.17.jar slf4j-api-1.7.5.jar slf4j-log4j12-1.7.5.jar classes12.jar Oracle10g的jar包
在src目录底下,建立sqlMapConfig.xml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> <!--配置数据源,环境--> <!--能够配置多个环境,一个测试时候用的,一个上线时候用的--> <environments default="test"> <!--测试环境--> <environment id="test"> <!--配置事务 : JDBC事务/MANAGED交给容器的事务--> <transactionManager type="JDBC"></transactionManager> <!--数据源 : POOLED池化/UNPOOLED非池化/JNDI密码加密,安全性高--> <dataSource type="POOLED"> <property name="driver" value="oracle.jdbc.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/> <property name="username" value="scott"/> <property name="password" value="luogg"/> </dataSource> </environment> <!--服务器环境--> <environment id="deploy"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="oracle.jdbc.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/> <property name="username" value="scott"/> <property name="password" value="luogg"/> </dataSource> </environment> </environments> <mappers> <mapper resource="com/luogg/mapper/PersonMapper.xml"/> </mappers> </configuration>
package test; import com.luogg.domain.Person; 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 org.junit.Test; import java.io.IOException; import java.io.InputStream; import java.util.List; /** * Created by luogg on 2017/2/17. */ public class TestMybatis { @Test public void init() throws IOException { /** * 测试数据库的链接 * 1.定义一个String类型的变量resource,指向刚才配置的链接数据库的xml文件 * 2.建立一个输入流,来读取咱们的数据库配置文件 * 3.输入流建立工厂. * 4.有了工厂以后open工厂 */ String resource = "sqlMapConfig.xml"; InputStream is = Resources.getResourceAsStream(resource); SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is); SqlSession session = factory.openSession(); }
此时,咱们能够进行单元测试了,看看session有没有被建立,绿色表示建立成功,那么咱们接下来建立数据库表,而且写sql语句web
CREATE TABLE person( ID NUMBER(2), NAME VARCHAR2(20), sex NUMBER(2), age NUMBER(3) ) -- 写入数据,点击下方锁子按钮,而后点击+ SELECT * FROM person FOR UPDATE
package com.luogg.domain; /** * Created by luogg on 2017/2/17. */ public class Person { private String name; private int sex; private int age; private int id; @Override public String toString() { return "Person{" + "name='" + name + '\'' + ", sex=" + sex + ", age=" + age + ", id=" + id + '}'; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getSex() { return sex; } public void setSex(int sex) { this.sex = sex; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
<?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"> <!--配置命名空间,命名空间+ .id 是惟一的sql语句标示符--> <mapper namespace="com.luogg.mapper.PersonMapper"> <!--查询全部数据,参数有id,resultType结果集,parameterType参数--> <!--注意 : sql语句中若是有要填写集合的,好比查询全部数据,返回一个Person的结果集,那么resultType参数直接写 路径+集合的类型 好比: 返回一个Person集合,那么就填写Person Bean所在的路径+Person--> <select id="find" resultType="com.luogg.domain.Person"> SELECT * from person </select> </mapper>
<?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> <!--配置数据源,环境--> <!--能够配置多个环境,一个测试时候用的,一个上线时候用的--> <environments default="test"> <!--测试环境--> <environment id="test"> <!--配置事务 : JDBC事务/MANAGED交给容器的事务--> <transactionManager type="JDBC"></transactionManager> <!--数据源 : POOLED池化/UNPOOLED非池化/JNDI密码加密,安全性高--> <dataSource type="POOLED"> <property name="driver" value="oracle.jdbc.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/> <property name="username" value="scott"/> <property name="password" value="luogg"/> </dataSource> </environment> <!--服务器环境--> <environment id="deploy"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="oracle.jdbc.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/> <property name="username" value="scott"/> <property name="password" value="luogg"/> </dataSource> </environment> </environments> <!--映射文件mapper--> <mappers> <mapper resource="com/luogg/mapper/PersonMapper.xml"/> </mappers> </configuration>
package test; import com.luogg.domain.Person; 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 org.junit.Test; import java.io.IOException; import java.io.InputStream; import java.util.List; /** * Created by luogg on 2017/2/17. */ public class TestMybatis { @Test public void init() throws IOException { /** * 测试数据库的链接 * 1.定义一个String类型的变量resource,指向刚才配置的链接数据库的xml文件 * 2.建立一个输入流,来读取咱们的数据库配置文件 * 3.输入流建立工厂. * 4.有了工厂以后open工厂 * 5.经过session访问配置文件中的sql语句 */ String resource = "sqlMapConfig.xml"; InputStream is = Resources.getResourceAsStream(resource); SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is); SqlSession session = factory.openSession(); //如何访问PersonMapper.xml中的sql语句呢? 命名空间+ .id List<Person> list = session.selectList("com.luogg.mapper.PersonMapper.find"); System.out.println(list.size()); for(Person p : list){ System.out.println(p); } } }