mybatis篇一、mybatis简单搭建demo

mybatis

为防止mapper.xml文件找不到时会报错 可在pom.xml中写入 文件过滤配置，文件过滤xml配置如下：

 <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

1 、mybatis基础搭建demo

一 、配置maven 依赖

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.3</version>
    <scope>compile</scope>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.18</version>
</dependency>

二、配置mybatis-config.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>
    <environments default="development">
        <environment id="development">
            <!-- 事务管理 -->
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost/mybatis?useUnicode=True&amp;serverTimezone=UTC&amp;
                characterEncoding=UTF-8&amp;useSSL=true"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
<!-- 每一个mapper.xml都需要到这里来注册-->
    <mappers>
        <mapper resource="com/hq/dao/UserMapper.xml"></mapper>
    </mappers>
</configuration>

三、配置mybatis工具类

private static SqlSessionFactory sqlSessionFactory=null;
static {
    String resource = "mybatis-config.xml";
    InputStream inputStream = null;
    try {
        inputStream = Resources.getResourceAsStream(resource);
    } catch (IOException e) {
        e.printStackTrace();
    }
    sqlSessionFactory= new SqlSessionFactoryBuilder().build(inputStream);
}
//从sqlSessionFactory 中获取sqlsession的实例
//sqlsession 完全包含了面向数据库执行sql命令的所有方法
public static SqlSession getSqlSession(){

    return  sqlSessionFactory.openSession();
}

四、pojo实体类

public class User {

    private  int id;
    private String name;
    private String password;

    public User(){}
    public User(int id, String name, String password) {
        this.id = id;
        this.name = name;
        this.password = password;
    }

    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 String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
} 

五、配置dao层接口及相应mapper.xml

public interface UserDao {
     List<User> getUserList();
}

<mapper namespace="com.hq.dao.UserDao">
    <select id="getUserList" resultType="com.hq.pojo.User">
                select * from user
    </select>
</mapper>

六 测试类

@Test
public void test(){
        //获取sqlsession对象
        SqlSession  sqlSession = MybatisUtils.getSqlSession();
        //方式一 执行
        try {
            UserDao userDao = sqlSession.getMapper(UserDao.class);
            List<User> userList = userDao.getUserList();
            for (User user : userList) {
                System.out.println(user.getName());
            }
        }catch (Exception e){

        }finally {
            sqlSession.close();
        }
    }