Mybatis 注解方式

1. 添加依賴與插件

   • 使用插件解決xml文件不能放入java包下的問(wèn)題

     <!--可以將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>
     

   • 相關(guān)依賴

     <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>
         <!--幫助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>
     

2. 配置Mybatis.xml配置文件

   • 使用properties標(biāo)簽導(dǎo)入db.properties的驅(qū)動(dòng)設(shè)置,設(shè)置environments標(biāo)簽屬性

     # 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"/>
             <!--設(shè)置連接池-->
             <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標(biāo)簽添加第三方LOG4J日志功能

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

     # log4j.properties文件,文件名固定不可變
     # 全局日志配置
     # 日志有四個(gè)級(jí)別 :error,warn,info,debug
     log4j.rootLogger=ERROR, stdout
     # MyBatis 日志配置 ,可自行設(shè)置追蹤路徑
     log4j.logger.dao=TRACE
     # 控制臺(tái)輸出
     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標(biāo)簽 加入別名設(shè)置

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

   • 映射器配置,可掃描dao包下的所有接口,如果有同名的映射配置也可掃描

      <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"/>
     
         <!--添加日志功能乎串，STDOUT_LOGGING不需要添加第三方j(luò)ar包-->
         <settings>
             <setting name="logImpl" value="LOG4J"/>
         </settings>
         <typeAliases>
             <package name="pojo"/>
         </typeAliases>
     
         <environments default="development">
             <environment id="development">
                 <transactionManager type="JDBC"/>
                 <!--設(shè)置連接池-->
                 <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>
     

3. dao接口

   • 直接添加注解@Select,@Insert,@Update,@Delete

   • 如果傳入一個(gè)參數(shù),使用#{任意字符}獲取

   • 如果傳入多個(gè)參數(shù),使用#{arg0},#{arg1}獲取

   • 或者直接傳入對(duì)象,使用#{對(duì)應(yīng)的參數(shù)名}獲取

   •  /**
          * 查詢所有的User對(duì)象
          * @return User對(duì)象的列表
          */
         @Select("select *from user")
         List<User> getAllUsers();
       
         /**
          * 新增一個(gè)user對(duì)象
          * @param user
          * @return
          */
         @Insert("insert into users values(#{uid},#{name},#{pass},#{phone})")
        int saveUser(User user);
     

4. 測(cè)試類(lèi)

   • 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);
         }
     }