本文共 11102 字，大约阅读时间需要 37 分钟。
看本文之前，请确保你已经在SpringBoot中集成MyBatis，并能正常使用。
如果没有，那么请先移步 做了解后，再按本文步骤操作。使用MyBatis在我们通过xml集中配置SQL，并通过创建接口Mapper文件来完成持久化DAO层（mybatis内部使用的是动态代理，所以我们不需要自己编写实现类）。
然而在实际开发中，单表操作非常多，如果你也想像JPA、JDBC那样做一个所谓的BaseDao。那么可以实现一个通用Mapper来达到目的。现在有现成的通用Mapper插件，我们无需重新创造轮子（代码是开源的，你也可以自己在其基础上修改）。
通用Mapper插件网址：
下面是使用方法（本文直接将分页插件PageHelper也集成了）：
一、添加或修改pom依赖org.mybatis mybatis 3.3.0 org.mybatis mybatis-spring 1.2.3 com.github.pagehelper pagehelper 4.1.1 tk.mybatis mapper 3.3.4
这里说一下，文章开始指定的那篇文章中直接依赖的mybatis的starter。因为本文在集成通用Mapper的时候直接使用出现了错误，所以将mybatis的starter中的Java类（它本身只有2个Java类，非常简单）拷贝到工程中，注释掉了头部的//@ConditionalOnBean(DataSource.class)，你不用去找那2个类的源码了，下面会粘贴出来。
二、将下面4个Java类加入到工程中
将文件
MybatisAutoConfiguration.javaMyBatisMapperScannerConfig.javaMybatisProperties.javaMyMapper.java添加到 org.springboot.sample.config.mybatis 中（包名根据自己工程修改）最有一个MyMapper.java要特别注意，不要把MyMapper放到同其他Mapper一起，该类不能被当做普通Mapper一样被扫描，否则会出错。
package org.springboot.sample.config.mybatis;import java.util.Properties;import javax.annotation.PostConstruct;import javax.sql.DataSource;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.apache.ibatis.plugin.Interceptor;import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.mybatis.spring.SqlSessionTemplate;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.autoconfigure.AutoConfigureAfter;import org.springframework.boot.autoconfigure.EnableAutoConfiguration;import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;import org.springframework.boot.context.properties.EnableConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.core.io.DefaultResourceLoader;import org.springframework.core.io.Resource;import org.springframework.core.io.ResourceLoader;import org.springframework.util.Assert;import org.springframework.util.StringUtils;import com.github.pagehelper.PageHelper;/** * {@link EnableAutoConfiguration Auto-Configuration} for Mybatis. Contributes a * {@link SqlSessionFactory} and a {@link SqlSessionTemplate}. * * If {@link org.mybatis.spring.annotation.MapperScan} is used, or a configuration file is * specified as a property, those will be considered, otherwise this auto-configuration * will attempt to register mappers based on the interface definitions in or under the * root auto-configuration package. * * @author Eddú Meléndez * @author Josh Long */@Configuration@ConditionalOnClass({ SqlSessionFactory.class, SqlSessionFactoryBean.class })//@ConditionalOnBean(DataSource.class)@EnableConfigurationProperties(MybatisProperties.class)@AutoConfigureAfter(DataSourceAutoConfiguration.class)public class MybatisAutoConfiguration { private static Log log = LogFactory.getLog(MybatisAutoConfiguration.class); @Autowired private MybatisProperties properties; @Autowired(required = false) private Interceptor[] interceptors; @Autowired private ResourceLoader resourceLoader = new DefaultResourceLoader(); @PostConstruct public void checkConfigFileExists() { if (this.properties.isCheckConfigLocation()) { Resource resource = this.resourceLoader .getResource(this.properties.getConfig()); Assert.state(resource.exists(), "Cannot find config location: " + resource + " (please add config file or check your Mybatis " + "configuration)"); } } @Bean(name = "sqlSessionFactory") @ConditionalOnMissingBean public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception { SqlSessionFactoryBean factory = new SqlSessionFactoryBean(); factory.setDataSource(dataSource); if (StringUtils.hasText(this.properties.getConfig())) { factory.setConfigLocation( this.resourceLoader.getResource(this.properties.getConfig())); } else { if (this.interceptors != null && this.interceptors.length > 0) { factory.setPlugins(this.interceptors); } factory.setTypeAliasesPackage(this.properties.getTypeAliasesPackage()); factory.setTypeHandlersPackage(this.properties.getTypeHandlersPackage()); factory.setMapperLocations(this.properties.getMapperLocations()); } return factory.getObject(); } @Bean @ConditionalOnMissingBean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) { return new SqlSessionTemplate(sqlSessionFactory, this.properties.getExecutorType()); } /** * 分页插件 * * @param dataSource * @return * @author SHANHY * @create 2016年2月18日 */ @Bean public PageHelper pageHelper(DataSource dataSource) { log.info("注册MyBatis分页插件PageHelper"); PageHelper pageHelper = new PageHelper(); Properties p = new Properties(); p.setProperty("offsetAsPageNum", "true"); p.setProperty("rowBoundsWithCount", "true"); p.setProperty("reasonable", "true"); pageHelper.setProperties(p); return pageHelper; } } package org.springboot.sample.config.mybatis;import java.util.Properties;import org.springframework.boot.autoconfigure.AutoConfigureAfter;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import tk.mybatis.spring.mapper.MapperScannerConfigurer;/** * MyBatis扫描接口，使用的tk.mybatis.spring.mapper.MapperScannerConfigurer * 如果你不使用通用Mapper，可以改为org.xxx... * */@Configuration//TODO 注意，由于MapperScannerConfigurer执行的比较早，所以必须有下面的注解@AutoConfigureAfter(MybatisAutoConfiguration.class)public class MyBatisMapperScannerConfig { @Bean public MapperScannerConfigurer mapperScannerConfigurer() { MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer(); mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory"); mapperScannerConfigurer.setBasePackage("org.springboot.sample.mapper"); Properties properties = new Properties(); // 这里要特别注意，不要把MyMapper放到 basePackage 中，也就是不能同其他Mapper一样被扫描到。 properties.setProperty("mappers", MyMapper.class.getName()); properties.setProperty("notEmpty", "false"); properties.setProperty("IDENTITY", "MYSQL"); mapperScannerConfigurer.setProperties(properties); return mapperScannerConfigurer; }} package org.springboot.sample.config.mybatis;import org.apache.ibatis.session.ExecutorType;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.core.io.Resource;/** * Configuration properties for Mybatis. * * @author Eddú Meléndez */@ConfigurationProperties(prefix = MybatisProperties.MYBATIS_PREFIX)public class MybatisProperties { public static final String MYBATIS_PREFIX = "mybatis"; /** * Config file path. */ private String config; /** * Location of mybatis mapper files. */ private Resource[] mapperLocations; /** * Package to scan domain objects. */ private String typeAliasesPackage; /** * Package to scan handlers. */ private String typeHandlersPackage; /** * Check the config file exists. */ private boolean checkConfigLocation = false; /** * Execution mode. */ private ExecutorType executorType = ExecutorType.SIMPLE; public String getConfig() { return this.config; } public void setConfig(String config) { this.config = config; } public Resource[] getMapperLocations() { return this.mapperLocations; } public void setMapperLocations(Resource[] mapperLocations) { this.mapperLocations = mapperLocations; } public String getTypeHandlersPackage() { return this.typeHandlersPackage; } public void setTypeHandlersPackage(String typeHandlersPackage) { this.typeHandlersPackage = typeHandlersPackage; } public String getTypeAliasesPackage() { return this.typeAliasesPackage; } public void setTypeAliasesPackage(String typeAliasesPackage) { this.typeAliasesPackage = typeAliasesPackage; } public boolean isCheckConfigLocation() { return this.checkConfigLocation; } public void setCheckConfigLocation(boolean checkConfigLocation) { this.checkConfigLocation = checkConfigLocation; } public ExecutorType getExecutorType() { return this.executorType; } public void setExecutorType(ExecutorType executorType) { this.executorType = executorType; }} package org.springboot.sample.config.mybatis;import tk.mybatis.mapper.common.Mapper;import tk.mybatis.mapper.common.MySqlMapper;/** * 被继承的Mapper，一般业务Mapper继承它 * */public interface MyMapperextends Mapper , MySqlMapper { //TODO //FIXME 特别注意，该接口不能被扫描到，否则会出错}
三、属性配置文件
属性配置文件中和文章开头指定的文章一样配置，没有什么修改，下面粘贴出来：mybatis.mapper-locations=classpath*:org/springboot/sample/mapper/sql/mysql/*Mapper.xmlmybatis.type-aliases-package=org.springboot.sample.entity
四、在业务Mapper中继承基础MyMapper接口
public interface StudentMapper extends MyMapper{ List likeName(String name); Student getById(int id); int add(Student stu); String getNameById(int id);}
然后在Service中使用即可，后面就没什么说的了。
@Servicepublic class StudentService { @Autowired private JdbcTemplate jdbcTemplate; @Autowired private StudentMapper studentMapper; @TargetDataSource(name="ds2") public List likeName(String name){ return studentMapper.likeName(name); } public int testSave(){ Student stu = new Student(); stu.setAge(33); stu.setName("测试新增"); stu.setSumScore("66"); stu.setAvgScore("22"); return studentMapper.insert(stu);//这里调用的是基础Mapper中的insert方法 }} 最后还有一点要说明，使用公共Mapper“可能”需要对实体类进行修改。如果你的实体字段和数据库字段不一致（或者实体名称和数据库表名不一致），这样才需要修改，例如：
/** * 学生实体 * * @author 单红宇(365384722) * @myblog http://blog.csdn.net/catoop/ * @create 2016年1月12日 */public class Student implements Serializable{ @Id private int id; private String name; @Column(name="SCORE_SUM") private String sumScore; @Column(name="SCORE_AVG") private String avgScore; private int age; // getter setter } 其他没有什么可说的了，请至少要到 把插件的其他说明再看一遍。