Mybatis的使用（实现一个简单的查询功能）

1.使用IDEA创建一个maven项目。 2.在src/main/java路径下建两个包，一个放实体类，一个放mapper接口及映射文件。 3.在pom.xml文件中导包 ps:sql server包需要先下载jar包，然后用命令行安装，才能在文件中导入。 pom.xml:

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>gbv</groupId> <artifactId>bkj</artifactId> <version>1.0-SNAPSHOT</version> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.0</version> </dependency> <dependency> <groupId>com.microsoft.sqlserver</groupId> <artifactId>sqljdbc4</artifactId> <version>4.2</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> </resources> </build> </project>

4.新建核心配置文件并编写。 SqlMapConfig.xml:

<?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> <typeAliases><!-- 配置实体类的别名--> <package name="orm.entity"/> </typeAliases> <environments default="MySQLDevelopment"> <environment id="MySQLDevelopment"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/> <property name="url" value="jdbc:sqlserver://127.0.0.1:1433;databasename=stu1"/> <property name="username" value="lwl"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <package name="mapper"/> </mappers> </configuration>

5.根据表编写实体类： Stu.java:

package entity; public class Stu { private int Cid; private String Cname; private int Tid; public int getCid() { return Cid; } public void setCid(int cid) { Cid = cid; } public String getCname() { return Cname; } public void setCname(String cname) { Cname = cname; } public int getTid() { return Tid; } public void setTid(int tid) { Tid = tid; } @Override public String toString() { return "Stu{" + "Cid=" + Cid + ", Cname='" + Cname + '\'' + ", Tid=" + Tid + '}'; } }

6.编写mapper接口： 7.新建配置文件（名字与接口名保持一致）：

8.编写测试类，实现查询功能： StuTest.java:

import entity.Stu; import mapper.StuMapper; 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.InputStream; import java.util.List; public class StuTest { @Test public void getsum() throws Exception { //1.加载核心配置文件 SqlSessionFactoryBuilder s = new SqlSessionFactoryBuilder(); InputStream is = Resources.getResourceAsStream("SqlMapConfig.xml"); //2.解析核心配置文件并创建SqlSessionFactor对象 SqlSessionFactory sf = s.build(is); //3.创建核心对象 SqlSession sqlSession = sf.openSession(); //4.得到Mapper代理对象 StuMapper sm = sqlSession.getMapper(StuMapper.class); //5.调用自定义的方法实现查询功能 List<Stu> ss = sm.getsum(); for (Stu s1:ss) { System.out.println(s1); } //6.关闭sqlSession sqlSession.close(); } }