Mybatis注解方法操作数据库

Java中使用Mybatis操作数据库主要有两种方法：注解和xml配置，注解相对比较简单和方便，两种方式的效果一致。本文以注解的方式说明用Mybatis访问数据库的方法

一、创建数据表(MySql)

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-- ---------------------------- -- Table structure for admininfo -- ---------------------------- DROP TABLE IF EXISTS `admininfo`; CREATE TABLE `admininfo` (   `ID` int(11) NOT NULL AUTO_INCREMENT,   `AdminName` varchar(20) NOT NULL,   PRIMARY KEY (`ID`) ) ENGINE=InnoDB AUTO_INCREMENT=25 DEFAULT CHARSET=latin1;

二、创建mybatis的配置文件：mybatisConf.xml，由于使用maven进行管理，所以放在java-->resources文件夹下，其它位置也可以，只有最终在\target\classes\mybatisConf.xml生成文件即可

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<?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>     <environments default="development">         <environment id="development">             <transactionManager type="JDBC" />             <!-- 配置数据库连接信息 -->             <dataSource type="POOLED">                 <property name="driver" value="com.mysql.jdbc.Driver" />                 <property name="url" value="jdbc:mysql://127.0.0.1/test" />                 <property name="username" value="root" />                 <property name="password" value="root" />             </dataSource>         </environment>     </environments>     <mappers>         <!-- 注册映射接口，该接口文件包含了数据访问方法和SQL -->         <mapper class="dal.dataaccess.IAdminInfoMapper" />     </mappers> </configuration>

三、创建IAdminInfoMapper文件（本文中包名为dal.dataaccess)

    该接口的功能主要是提供对AdminInfo表的数据操作

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package dal.dataaccess;   import java.util.List; import org.apache.ibatis.annotations.Delete; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.annotations.Update; import dal.beans.AdminInfo; import dal.beans.AdminRightInfo;   public interface IAdminInfoMapper {           //使用@Select注解指明getById方法要执行的SQL     @Select("select * from admininfo where id=#{id}")     public AdminInfo getById(int id);           //使用@Select注解指明getAll方法要执行的SQL     @Select("select * from admininfo")     public List<AdminInfo> getAll();           //使用@Insert注解指明add方法要执行的SQL     @Insert("insert into admininfo(adminName) values(#{adminName})")     public int add(AdminInfo user);           //使用@Update注解指明update方法要执行的SQL     @Update("update admininfo set adminName=#{adminName} where id=#{id}")     public int update(AdminInfo user);           //使用@Delete注解指明deleteById方法要执行的SQL     @Delete("delete from admininfo where id=#{id}")     public int deleteById(int id); }

四、定义操作数据库的公共方法

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package framework.utils;   import java.io.InputStream;   import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder;   public class MyBatisUtil {     /**      * 获取SqlSessionFactory      *      * @return SqlSessionFactory      */     public static SqlSessionFactory getSqlSessionFactory() {         String resource = "mybatisConf.xml";         InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream(resource);         SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);         return factory;     }       /**      * 获取SqlSession      *      * @return SqlSession      */     public static SqlSession getSqlSession() {         return getSqlSessionFactory().openSession();     }       /**      * 获取SqlSession      *      * @param isAutoCommit      *            true 表示创建的SqlSession对象在执行完SQL之后会自动提交事务 false      *            表示创建的SqlSession对象在执行完SQL之后不会自动提交事务，这时就需要我们手动调用sqlSession.      *            commit()提交事务      * @return SqlSession      */     public static SqlSession getSqlSession(boolean isAutoCommit) {         return getSqlSessionFactory().openSession(isAutoCommit);     } }

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五、对adminInfo表进行增删改查

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package test;   import java.util.List; import org.apache.ibatis.session.SqlSession; import org.junit.Test; import dal.beans.*; import framework.utils.MyBatisUtil; import dal.dataaccess.*;   public class MybatisAnnotationTest {       // http://www.cnblogs.com/xdp-gacl/p/4261895.html     @Test     public void Select() {         SqlSession sqlSession = MyBatisUtil.getSqlSession();         // 得到AdminInfoMapper接口的实现类对象，IAdminInfoMapper接口的实现类对象由sqlSession.getMapper(IAdminInfoMapper.class)动态构建出来         IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);         // 执行查询操作，将查询结果自动封装成User返回         AdminInfo bean = mapper.getById(13);         // 使用SqlSession执行完SQL之后需要关闭SqlSession         sqlSession.close();         System.out.println(bean.getId());         System.out.println(bean.getAdminName());     }       @Test     public void SelectAll() {         SqlSession sqlSession = MyBatisUtil.getSqlSession();         IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);         List<AdminInfo> bean = mapper.getAll();         sqlSession.close();           System.out.println(bean.size());     }       @Test     public void Insert() {         SqlSession sqlSession = MyBatisUtil.getSqlSession();         IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);           AdminInfo bean = new AdminInfo();         bean.setAdminName("Admin" + System.currentTimeMillis());           int result = mapper.add(bean);         sqlSession.commit();         sqlSession.close();           System.out.println(result);     }       @Test     public void Update() {         SqlSession sqlSession = MyBatisUtil.getSqlSession();         IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);           AdminInfo bean = new AdminInfo();         bean.setId(12);         bean.setAdminName("Admin" + System.currentTimeMillis());           int result = mapper.update(bean);         sqlSession.commit();         sqlSession.close();           System.out.println(result);     }       @Test     public void Delete() {           SqlSession sqlSession = MyBatisUtil.getSqlSession();         IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);           int result = mapper.deleteById(12);         sqlSession.commit();         sqlSession.close();           System.out.println(result);     } }

六、由于使用了maven进行依赖管理，pom.xml还需要添加

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<dependency>         <groupId>mysql</groupId>         <artifactId>mysql-connector-java</artifactId>         <version>5.1.38</version>     </dependency>     <dependency>         <groupId>org.mybatis</groupId>         <artifactId>mybatis</artifactId>         <version>3.3.0</version>     </dependency>

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