Mybatis 注解方式

添加依赖与插件

使用插件解决xml文件不能放入java包下的问题

<!--可以将xml文件建于java包下并且可被映射-->
<build>
    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.xml</include>
            </includes>
        </resource>
    </resources>
</build>

相关依赖

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.44</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>
    <!--帮助pojo快速生成getter和setting-->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.6</version>
    </dependency>

    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>

</dependencies>

配置Mybatis.xml配置文件

使用properties标签导入db.properties的驱动设置,设置environments标签属性

# db.properties文件
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3307/shop_mybatis
username=root
password=970809

<environments default="development">
    <environment id="development">
        <transactionManager type="JDBC"/>
        <!--设置连接池-->
        <dataSource type="POOLED">
            <property name="driver" value="${driver}"/>
            <property name="url" value="${url}"/>
            <property name="username" value="${username}"/>
            <property name="password" value="${password}"/>
        </dataSource>
    </environment>
</environments>

使用settings标签添加第三方LOG4J日志功能

<settings>
    <setting name="logImpl" value="LOG4J"/>
</settings>

# log4j.properties文件,文件名固定不可变
# 全局日志配置
# 日志有四个级别 :error,warn,info,debug
log4j.rootLogger=ERROR, stdout
# MyBatis 日志配置 ,可自行设置追踪路径
log4j.logger.dao=TRACE
# 控制台输出
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

使用typeAliases标签加入别名设置

<typeAliases>s
    <package name="pojo"/>
</typeAliases>

映射器配置,可扫描dao包下的所有接口,如果有同名的映射配置也可扫描
```
 <mappers>
        <package name="dao"/>
 </mappers>
```

完整配置

<?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>
    <properties resource="db.properties"/>

    <!--添加日志功能，STDOUT_LOGGING不需要添加第三方jar包-->
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>
    <typeAliases>
        <package name="pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <!--设置连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    
    <mappers>
<!--        <mapper resource="com/mapper/OrderMapper.xml"/>-->
<!--        <mapper resource="com/mapper/UserMapper.xml"/>-->
<!--        <mapper resource="com/mapper/DetailMapper.xml"/>-->
<!--        <mapper resource="com/mapper/ProductMapper.xml"/>-->
<!--        <mapper resource="com/mapper/TypeMapper.xml"/>-->
<!--        <mapper class="dao.IUserDao2"/>-->
        <package name="dao"/>
    </mappers>
</configuration>

dao接口

直接添加注解@Select,@Insert,@Update,@Delete
如果传入一个参数,使用#{任意字符}获取
如果传入多个参数,使用#{arg0},#{arg1}获取
或者直接传入对象,使用#{对应的参数名}获取

 /**
     * 查询所有的User对象
     * @return User对象的列表
     */
    @Select("select *from user")
    List<User> getAllUsers();
  
    /**
     * 新增一个user对象
     * @param user
     * @return
     */
    @Insert("insert into users values(#{uid},#{name},#{pass},#{phone})")
   int saveUser(User user);

测试类

public class TestUserDao {

    private SqlSession session = null;

    @Before
    public void setUp() {
        session = SessionUtils.getSession();
    }

    @After
    public void tearDown() {
        SessionUtils.closeSession();
    }

    @Test
    public void testGetAllUsers() {
        IUserDao mapper = session.getMapper(IUserDao2.class);


        List<User> users = mapper.getAllUsers();

        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testSaveUser() {
        IUserDao2 userDao = session.getMapper(IUserDao2.class);
        User u = new User("3", "cpj", "123", "12312312");
        userDao.saveUser(u);
    }
}

#千锋逆战# Mybatis注解方式实现

#千锋逆战# Mybatis注解方式实现

Mybatis 注解方式

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