mybatis dao 层开发简易版 非整合 spring

同样老习惯，先上项目结构截图

首先 补充上篇文中缺失的 mysql demo 用的 小脚本

drop database  if exists mybatis;
 
CREATE DATABASE `mybatis` DEFAULT CHARACTER SET utf8 ;
 
use mybatis;
/*
SQLyog v10.2
MySQL - 5.1.72-community : Database - mybatis
*********************************************************************
*/
/*Table structure for table `items` */
 
CREATE TABLE `items` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL COMMENT '商品名称',
  `price` float(10,1) NOT NULL COMMENT '商品定价',
  `detail` text COMMENT '商品描述',
  `pic` varchar(64) DEFAULT NULL COMMENT '商品图片',
  `createtime` datetime NOT NULL COMMENT '生产日期',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
 
/*Table structure for table `user` */
 
CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(32) NOT NULL COMMENT '用户名称',
  `birthday` date DEFAULT NULL COMMENT '生日',
  `sex` char(1) DEFAULT NULL COMMENT '性别',
  `address` varchar(256) DEFAULT NULL COMMENT '地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8;
 
/*Table structure for table `orders` */
 
CREATE TABLE `orders` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) NOT NULL COMMENT '下单用户id',
  `number` varchar(32) NOT NULL COMMENT '订单号',
  `createtime` datetime NOT NULL COMMENT '创建订单时间',
  `note` varchar(100) DEFAULT NULL COMMENT '备注',
  PRIMARY KEY (`id`),
  KEY `FK_orders_1` (`user_id`),
  CONSTRAINT `FK_orders_id` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
 
/*Table structure for table `orderdetail` */
 
CREATE TABLE `orderdetail` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `orders_id` int(11) NOT NULL COMMENT '订单id',
  `items_id` int(11) NOT NULL COMMENT '商品id',
  `items_num` int(11) DEFAULT NULL COMMENT '商品购买数量',
  PRIMARY KEY (`id`),
  KEY `FK_orderdetail_1` (`orders_id`),
  KEY `FK_orderdetail_2` (`items_id`),
  CONSTRAINT `FK_orderdetail_1` FOREIGN KEY (`orders_id`) REFERENCES `orders` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `FK_orderdetail_2` FOREIGN KEY (`items_id`) REFERENCES `items` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

mysql 数据库及表结构

/*
SQLyog v10.2
MySQL - 5.1.72-community : Database - mybatis
*********************************************************************
*/
/*Data for the table `items` */
 
insert  into `items`(`id`,`name`,`price`,`detail`,`pic`,`createtime`) values (1,'台式机',3000.0,'该电脑质量非常好！！！！',NULL,'2016-02-03 13:22:53'),(2,'笔记本',6000.0,'笔记本性能好，质量好！！！！！',NULL,'2015-02-09 13:22:57'),(3,'背包',200.0,'名牌背包，容量大质量好！！！！',NULL,'2016-02-06 13:23:02');
 
/*Data for the table `user` */
 
insert  into `user`(`id`,`username`,`birthday`,`sex`,`address`) values (1,'王五',NULL,'',NULL),(10,'张三','2016-07-10','','北京市'),(16,'张小明',NULL,'','河南郑州'),(22,'陈小明',NULL,'','河南郑州'),(24,'张三丰',NULL,'','河南郑州'),(25,'陈小明',NULL,'','河南郑州'),(26,'王五',NULL,NULL,NULL);
 
/*Data for the table `orders` */
 
insert  into `orders`(`id`,`user_id`,`number`,`createtime`,`note`) values (3,1,'','2016-02-04 13:22:35',NULL),(4,1,'','2016-02-03 13:22:41',NULL),(5,10,'','2016-02-12 16:13:23',NULL);
 
/*Data for the table `orderdetail` */
 
insert  into `orderdetail`(`id`,`orders_id`,`items_id`,`items_num`) values (1,3,1,1),(2,3,2,3),(3,4,3,4),(4,4,2,3);

mysql 插入测试数据脚本

工程采用 maven 管理，pom.xml 内容如下

<?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>com.ghc</groupId>
  <artifactId>mybatisdao</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>
 
  <name>mybatisdao Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>
 
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>
 
  <dependencies>
    <!-- https://mvnrepository.com/artifact/junit/junit -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
 
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.6</version>
    </dependency>
 
    <!-- https://mvnrepository.com/artifact/log4j/log4j -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
 
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.18</version>
    </dependency>
 
  </dependencies>
 
  <build>
    <finalName>mybatisdao</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.7.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.20.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

pom.xml

接下来就是 四个 配置文件了， 其中 db.properties 里的 key 到 SqlMappingConfig.xml 里就引用不到，这点作为初学者也觉得无奈，暂且就硬编码吧

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=UTF-8
jdbc.username=root
jdbc.password=Mede645

db.properties 引用不到显得可有可无

log4j.rootLogger=DEBUG,A1
log4j.logger.org.springframework=debug
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d %5p [%t] (%F:%L) - %m%n

log4j.properties 不用重点关注

下面这个很重要很重要，是入口配置文件

<?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>
 
    <!-- 加载属性文件 -->
    <properties resource="db.properties">
        <!--properties中还可以配置一些属性名和属性值 -->
        <!-- <property name="jdbc.driver" value=""/> -->
    </properties>
 
    <typeAliases>
 
        <typeAlias type="com.ghc.pojo.User" alias="user" />
 
    </typeAliases>
 
    <!-- 和spring整合后 environments配置将废除 -->
    <environments default="development">
        <environment id="development">
            <!-- 使用jdbc事务管理，事务控制由mybatis -->
            <transactionManager type="JDBC" />
            <!-- 数据库连接池，由mybatis管理 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=UTF-8" />
                <property name="username" value="root" />
                <property name="password" value="Mede645" />
            </dataSource>
        </environment>
    </environments>
 
    <mappers>
        <mapper resource="User.xml"/>
    </mappers>
 
</configuration>

SqlMappingConfig.xml 很重要很重要

<?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.ghc.dao.UserDao">
    <select id="findUserById" parameterType="java.lang.Integer" resultType="user">
        SELECT * FROM user WHERE id =#{userid} <!--简单类型 随意取名-->
    </select>
 
</mapper>

User.xml 这个配置文件也比较重要

<select id="findUserLike" parameterType="java.lang.String" resultType="user">
        SELECT * FROM user WHERE username LIKE '%${value}%'
    </select>
    <insert id="addUser" parameterType="user">
        INSERT INTO user(username,birthday,sex,address) values(#{userName},#{birthday},#{sex},#{address})
    </insert>
    <delete id="deleteUserById" parameterType="int">
        DELETE FROM user WHERE id=#{id}
    </delete>
    <update id="updateUserById" parameterType="user">
        UPDATE user set username=#{userName},birthday= #{birthday},sex=#{sex},address=#{address} WHERE id = #{id}
    </update>
 
上面是新增的 部分，下面请拷贝如有需要
 
<?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.ghc.dao.UserDao">
    <select id="findUserById" parameterType="java.lang.Integer" resultType="user">
        SELECT * FROM user WHERE id =#{userid} <!--简单类型 随意取名-->
    </select>
 
    <select id="findUserLike" parameterType="java.lang.String" resultType="user">
        SELECT * FROM user WHERE username LIKE '%${value}%'
    </select>
    <insert id="addUser" parameterType="user">
        INSERT INTO user(username,birthday,sex,address) values(#{userName},#{birthday},#{sex},#{address})
    </insert>
    <delete id="deleteUserById" parameterType="int">
        DELETE FROM user WHERE id=#{id}
    </delete>
    <update id="updateUserById" parameterType="user">
        UPDATE user set username=#{userName},birthday= #{birthday},sex=#{sex},address=#{address} WHERE id = #{id}
    </update>
</mapper>

修改后的 User.xml

与持久层映射的 pojo 对象 ， 就是 简单java 对象的意思，没事儿别整高大上，故作高深。。。。

package com.ghc.pojo;
 
import java.util.Date;
 
public class User {
    private int id;
    private String userName;
    private Date birthday;
    private String sex;
    private String address;
 
    public int getId() {
        return id;
    }
 
    public void setId(int id) {
        this.id = id;
    }
 
    public String getUserName() {
        return userName;
    }
 
    public void setUserName(String userName) {
        this.userName = userName;
    }
 
    public Date getBirthday() {
        return birthday;
    }
 
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
 
    public String getSex() {
        return sex;
    }
 
    public void setSex(String sex) {
        this.sex = sex;
    }
 
    public String getAddress() {
        return address;
    }
 
    public void setAddress(String address) {
        this.address = address;
    }
}

com.ghc.pojo.User

第一种方法采用 原始 dao 开发方法即先写 dao 接口，再写其实现类

package com.ghc.dao;
import com.ghc.pojo.User;
public interface UserDao{
    public User findUserById(int id) throws Exception;
}

com.ghc.dao.UserDao 接口

package com.ghc.dao;
 
import com.ghc.pojo.User;
import org.apache.ibatis.jdbc.SQL;
import org.apache.ibatis.session.SqlSessionFactory;
 
import java.io.IOException;
 
public class UserDaoImp implements UserDao {
    // 由于没有整合，这里无法使用spring容器自动注入，手动采取构造函数注入
    // SqlSessionFactoryBuilder 看做工具类，而 SqlSessionFactor 做成单例
    //private SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
    private SqlSessionFactory sqlSessionFactory;
    public UserDaoImp(SqlSessionFactory sqlSessionFactory){
        this.sqlSessionFactory = sqlSessionFactory;
    }
    @Override
    public User findUserById(int id) throws IOException {
           return sqlSessionFactory.openSession().selectOne("com.ghc.dao.UserDao.findUserById",id);
    }
}

com.ghc.UserDaoImp 接口实现类

package com.ghc.dao;
import com.ghc.pojo.User;
 
import java.util.List;
 
public interface UserDao{
    User findUserById(int id) throws Exception;
    List<User> findUserLike(String userName) throws Exception;
    void addUser(User user) throws Exception;
    void deleteUserById(int id) throws Exception;
    void updateUserById(User user) throws Exception;
}

添加新功能的dao层接口

package com.ghc.dao;
 
import com.ghc.pojo.User;
import org.apache.ibatis.jdbc.SQL;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
 
import java.io.IOException;
import java.util.List;
 
public class UserDaoImp implements UserDao {
    // 由于没有整合，这里无法使用spring容器自动注入，手动采取构造函数注入
    // SqlSessionFactoryBuilder 看做工具类，而 SqlSessionFactor 做成单例
    //private SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
    private SqlSessionFactory sqlSessionFactory;
    public UserDaoImp(SqlSessionFactory sqlSessionFactory){
        this.sqlSessionFactory = sqlSessionFactory;
    }
    @Override
    public User findUserById(int id) throws IOException {
           return sqlSessionFactory.openSession().selectOne("com.ghc.dao.UserDao.findUserById",id);
    }
 
    @Override
    public List<User> findUserLike(String userName) throws Exception {
        return sqlSessionFactory.openSession().selectList("com.ghc.dao.UserDao.findUserLike",userName);
    }
 
    @Override
    public void addUser(User user) throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        sqlSession.insert("com.ghc.dao.UserDao.addUser",user);
        sqlSession.commit();
    }
 
    @Override
    public void deleteUserById(int id) throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        sqlSession.delete("com.ghc.dao.UserDao.deleteUserById",id );
        sqlSession.commit();
    }
 
    @Override
    public void updateUserById(User user) throws Exception {
        SqlSession sqlSession= sqlSessionFactory.openSession();
        sqlSession.update("com.ghc.dao.UserDao.updateUserById",user);
        sqlSession.commit();
    }
 
}

添加新功能后的dao层实现类

既然第一个 UserDao 开发好了，我们就可以直接拿来测试一波了

import com.ghc.dao.UserDao;
import com.ghc.dao.UserDaoImp;
import com.ghc.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
 
public class UserDaoTest {
    @Test
    public void testUserDao() throws Exception{
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("SqlMappingConfig.xml"));
        UserDao userDao = new UserDaoImp(sqlSessionFactory);
        User user = userDao.findUserById(1);
        System.out.println(user.getUserName());
    }
}

junit测试一波咯

import com.ghc.dao.UserDao;
import com.ghc.dao.UserDaoImp;
import com.ghc.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
 
import java.util.List;
import java.util.Date;
 
public class UserDaoTest {
    @Test
    public void testUserDao() throws Exception{
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("SqlMappingConfig.xml"));
        UserDao userDao = new UserDaoImp(sqlSessionFactory);
        User user = userDao.findUserById(1);
        System.out.println(user.getUserName());
        List<User> userList = userDao.findUserLike("小明");
        for(User u:userList){
            System.out.println(u.getUserName());
        }
 
        User user1 = new User();
        user1.setUserName("孔方兄");
        user1.setSex("某");
        user1.setBirthday(new Date());
        user1.setAddress("麓谷");
        userDao.addUser(user1);
 
       // userDao.deleteUserById(1);  因为主外键的问题所以暂注释掉
 
        // update 方法
        User user2 = new User();
        user2.setId(43);
        user2.setUserName("黑钻石王老五");
        user2.setBirthday(new Date());
        user2.setSex("南");
        user2.setAddress("北京天安门");
        userDao.updateUserById(user2);
    }
}

添加新功能后的测试文件

测试结果：

待续 第二种 只写接口方法。。。