要使用Guice简化Mybatis的依赖注入,你需要遵循以下步骤:
在你的项目中添加Guice和Mybatis的依赖。如果你使用的是Maven,可以在pom.xml文件中添加以下依赖:
<dependencies>
<!-- Guice -->
<dependency>
<groupId>com.google.inject</groupId>
<artifactId>guice</artifactId>
<version>4.2.3</version>
</dependency>
<dependency>
<groupId>com.google.inject.extensions</groupId>
<artifactId>guice-servlet</artifactId>
<version>4.2.3</version>
</dependency>
<!-- Mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.7</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.6</version>
</dependency>
</dependencies>
创建一个Guice模块,用于绑定Mybatis的Mapper接口和实现类。例如,你可以创建一个名为MybatisModule
的类:
import com.google.inject.AbstractModule;
import com.google.inject.name.Names;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.sql.DataSource;
@Configuration
@MapperScan(basePackages = "com.example.yourproject.mapper", sqlSessionTemplateRef = "sqlSessionTemplate")
public class MybatisModule extends AbstractModule {
@Bean
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
sessionFactoryBean.setDataSource(dataSource);
return sessionFactoryBean.getObject();
}
@Bean
public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
在这个例子中,我们使用@MapperScan
注解来指定Mapper接口所在的包,并引用sqlSessionTemplate
。
在你的Service类中,使用Guice的@Inject
注解来注入Mapper接口。例如:
import com.example.yourproject.mapper.UserMapper;
import com.google.inject.Inject;
import org.springframework.stereotype.Service;
@Service
public class UserService {
private final UserMapper userMapper;
@Inject
public UserService(UserMapper userMapper) {
this.userMapper = userMapper;
}
// 使用userMapper进行数据库操作
}
在你的Spring配置类中,添加Guice的Injector
和ServletModule
。例如:
import com.google.inject.Injector;
import com.google.inject.servlet.GuiceServletContextListener;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public class AppServletContextListener implements ServletContextListener {
@Override
public void contextInitialized(ServletContextEvent sce) {
Injector injector = Guice.createInjector(new MybatisModule());
WebApplicationContext webApplicationContext = new WebApplicationContext();
webApplicationContext.setInjector(injector);
sce.getServletContext().setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_KEY, webApplicationContext);
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
}
}
然后,在你的web.xml
文件中,添加Guice的ServletModule
和ContextLoaderListener
:
<listener>
<listener-class>com.google.inject.servlet.GuiceServletContextListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
现在,你已经成功地使用Guice简化了Mybatis的依赖注入。在运行时,Guice会自动创建UserMapper
的实例并将其注入到UserService
中。