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怎样利用Guice简化Mybatis的依赖注入

小樊
82
2024-10-13 16:49:43
栏目: 编程语言

要使用Guice简化Mybatis的依赖注入,你需要遵循以下步骤:

  1. 添加依赖

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>
  1. 创建Guice模块

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

  1. 使用Guice注入依赖

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
}
  1. 配置Guice和Spring集成

在你的Spring配置类中,添加Guice的InjectorServletModule。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ServletModuleContextLoaderListener

<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。

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