mybaits2-Dao开发
项目结构：
1、创建project，导入相关依赖（前提）。配置db.properties与mybaits-config
#mysql驱动 db.driver=com.mysql.jdbc.Driver #mysql数据库连接信息 #端口号后信息：数据库名字，是否设置数据库编码，字符编码，是否使用SSl #SSL协议提供的服务主要有： #1）认证用户和服务器，确保数据发送到正确的客户机和服务器； #2）加密数据以防止数据中途被窃取； #3）维护数据的完整性，确保数据在传输过程中不被改变。 db.url=jdbc:mysql://localhost:3306/mybatis_wjw?useUnicode=true&characterEncoding=UTF-8&useSSL=false #数据库用户 db.username=root #数据库密码 db.password=xxxx
<?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>
<!--加载db.properties -->
<properties resource="db.properties"></properties>
<!--设置别名 -->
<typeAliases>
<!--单个别名设置 -->
<!-- <typeAlias type="schema.User" alias="user"/> -->
<package name="Dao"/>
</typeAliases>
<!-- mybatis环境变量配置信息 -->
<environments default="development">
<environment id="development">
<!-- jdbc事务控制管理，这里由mybatis管理 -->
<transactionManager type="JDBC"/>
<!-- 数据源配置 -->
<dataSource type="POOLED">
<property name="driver" value="${db.driver}"/>
<property name="url" value="${db.url}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
</dataSource>
</environment>
</environments>
<!--映射文件管理 -->
<mappers>
<!--通过mapper.xml文件配置 -->
<mapper resource="dao/User.xml"/>
<!--通过类名 必需是mapper代理开发 -->
<!--<mapper class="dao.User"/> -->
<!--批量配置，推荐使用 -->
<!--<package name="dao"/>-->
</mappers>
</configuration>
2、创建单例模式SQLSessionFctory 和 SqlSession
package pubfun;
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 java.io.IOException;
public class GetSqlSession {
public static SqlSession getSqlSession(){
return InitSqlSessionFactory.ssf.openSession();
}
private static class InitSqlSessionFactory{
private volatile static SqlSessionFactory ssf = getSqlSessionFaactory();
private static SqlSessionFactory getSqlSessionFaactory(){
try {
if(ssf==null){
ssf = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("SqlMapConfig.xml") );
}
} catch (IOException e) {
e.printStackTrace();
}
return ssf;
}
}
public static void main(String args[]){
for (int i = 0; i < 5; i++) {
new Thread(()->{
SqlSession ss = getSqlSession();
System.out.println("ss:"+ss);
}).start();
}
}
}
3、实现Dao层
<?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="user">
<select id="getByIdSchema" parameterType="int" resultType="schema.User">
select * from t_user where tid = #{value}
</select>
<parameterMap id="UserParameter" type="java.util.Map">
<parameter property="tid" javaType="java.lang.Integer"></parameter>
<parameter property="uname" javaType="java.lang.String" ></parameter>
<parameter property="birthday" javaType="java.util.Date"></parameter>
<parameter property="sex" javaType="java.lang.Character"></parameter>
<parameter property="address" javaType="java.lang.String" ></parameter>
</parameterMap>
<resultMap id="UserResult" type="schema.User">
<id column="id" property="tid"></id>
<result column="name" property="uname"></result>
<result column="birthday" property="birthday"></result>
<result column="sex" property="sex"></result>
<result column="address" property="address"></result>
</resultMap>
<select id="getByConditionListSchema" parameterMap="UserParameter" resultType="schema.User">
select * from t_user where 1=1 and uname like concat('%',#{uname},'%') and address = #{address}
</select>
<!--<insert id="insertUser" parameterMap="schema.User" >-->
<!--insert into t_user values(#{id},#{name},#{birthday},#{sex},#{address})-->
<!--</insert>-->
<!--<delete id="deleteUser" parameterMap="schema.User" >-->
<!--delete from t_user where id = #{id}-->
<!--</delete>-->
<!--<update id="updateUser" parameterMap="schema.User">-->
<!--update from t_user where id = #{id}-->
<!--</update>-->
</mapper>
package dao;
import org.apache.ibatis.session.SqlSessionFactory;
import schema.User;
import java.util.List;
import java.util.Map;
public interface Dao{
public SqlSessionFactory ssf = null;
//使用主键查询
public Object getByIdSchema(int i);
//使用非主键查询返回list
public List getByConditionListSchema(Map map);
}
package dao;
import org.apache.ibatis.session.SqlSession;
import pubfun.GetSqlSession;
import schema.User;
import java.util.List;
import java.util.Map;
public class UserDao implements Dao {
@Override
public Object getByIdSchema(int i) {
SqlSession ss = GetSqlSession.getSqlSession();
User user = ss.selectOne("user.getByIdSchema",i);
ss.close();
return user;
}
@Override
public List getByConditionListSchema(Map map) {
SqlSession ss = GetSqlSession.getSqlSession();
List<User> list= ss.selectList("user.getByConditionListSchema",map);
ss.close();
return list;
}
}
4、测试
import dao.Dao;
import dao.UserDao;
import schema.User;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class Main {
public static void main(String[] args) {
Dao ud = new UserDao();
System.out.println(ud.getByIdSchema(3));
Map user = new HashMap();
user.put("uname","二");
user.put("address","湖南长沙");
List list = ud.getByConditionListSchema(user);
System.out.println(list);
}
}
数据库：
