为什么要学习Mybatis的通用Mapper,相信也不用我做太多介绍,总之他能简化我们开发过程中对数据库的单表操作。
这里详细讲解一下Spring环境下配置Mybatis通用Mapper以及代码生成器的过程
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pom.xml中引入依赖
<!--tk.mybatis/mapper --> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>3.3.8</version> </dependency> <!--mybatis-generator-core --> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.3</version> </dependency>
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pom.xml中配置代码生成器插件
<properties> <!-- MyBatis Generator --> <!-- Java接口和实体类 --> <targetJavaProject>${basedir}/src/main/java</targetJavaProject> <!-- mapper接口的生成位置 --> <targetMapperPackage>fei.mapper</targetMapperPackage> <!-- 实体类的生成位置 --> <targetModelPackage>fei.entity</targetModelPackage> <!-- MyBatis Generator mapper.xml生成位置 --> <targetResourcesProject>${basedir}/src/main/resources</targetResourcesProject> <targetXMLPackage>fei.mapper</targetXMLPackage> </properties> ...... <!--通用mapper自动生成插件--> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <configuration> <!--代码生成器配置文件路径--> <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile> <!--是否覆盖已经存在的文件--> <overwrite>true</overwrite> <verbose>true</verbose> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.21</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>3.3.8</version> </dependency> </dependencies> </plugin>
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编写代码生成器配置文件
generatorConfig.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"> <generatorConfiguration> <!--加载配置文件取值--> <properties resource="classpath:generator.properties"/> <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat"> <property name="beginningDelimiter" value="`"/> <property name="endingDelimiter" value="`"/> <plugin type="${mapper.plugin}"> <!--自定义通用Mapper接口,将来所有生成的mapper接口都会继承这个接口--> <property name="mappers" value="${mapper.Mapper}"/> <!--强制生成注解,不管entity与表名是否一致--> <property name="forceAnnotation" value="true"/> <!--区分大小写--> <property name="caseSensitive" value="true"/> </plugin> <!--连接数据库--> <jdbcConnection driverClass="${jdbc.driver}" connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"> </jdbcConnection> <!--pom.xml配置的文件生成路径--> <javaModelGenerator targetPackage="${targetModelPackage}" targetProject="${targetJavaProject}"/> <sqlMapGenerator targetPackage="${targetXMLPackage}" targetProject="${targetResourcesProject}"/> <javaClientGenerator targetPackage="${targetMapperPackage}" targetProject="${targetJavaProject}" type="XMLMAPPER" /> <!--可以指定数据库中的某个表,%表示所有表--> <table tableName="%" > <generatedKey column="user_id" sqlStatement="Mysql" identity="true"/> </table> </context> </generatorConfiguration>
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resources根目录下定义需要加载的配置文件
generator.properties
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8 jdbc.username=root jdbc.password=1111 mapper.plugin = tk.mybatis.mapper.generator.MapperPlugin mapper.Mapper =fei.dao.BaseMapper
注意我的
fei.dao.BaseMapper
继承了extends Mapper<T>, MySqlMapper<T>
,前面配置了所有自动生成的mapper接口都继承这个接口 -
然后将原来mybatis-batis.xml文件中的
<!-- 配置Mapper接口扫描 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 配置Mapper扫描包 --> <property name="basePackage" value="fei.mapper" /> </bean>
改成
<!-- 配置Mapper接口扫描 --> <bean class="tk.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 配置Mapper扫描包 --> <property name="basePackage" value="fei.mapper" /> </bean>
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最后测试启动
没有报错,应该就在指定位置可以看到自动生成的实体类,Mapper接口,Mapper.xml文件如自动帮我们生成的实体类
@Table(name = "customer") public class Customer { @Id @Column(name = "cust_id") private Integer custId; @Column(name = "cust_name") private String custName; @Column(name = "cust_profession") private String custProfession; @Column(name = "cust_phone") private String custPhone; ......