Spring Framework Integration with MyBatis: Core Implementation Mechanisms

Circular Dependency Resolution in Spring

Understanding Circular Dependencies

Circular dependencies occur when two or more beans depend on each other, creating a dependency cycle. Spring handles this through a three-level caching mechanism.

Early AOP and Caching Mechanism

The earlySingletonObjects cache (second-level) stores partially constructed bean instances that have undergone AOP processing. The singletonFactory cache (third-level) contains ObjectFactory instances capable of creating bean proxies when needed.

@Lazy Annotation Resolution

The @Lazy annotation breaks circular dependencies by deferring bean initialization until actual usage, preventing instantiation cycles during application context startup.

Spring-MyBatis Integration Architecture

Phase 1: Basic Configuration Setup

Project Structure and Dependencies

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.1.9.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>
</dependencies>

MyBatis Configuration

<configuration>
    <environments default="development">
        <environment id="development">
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/test"/>
            </dataSource>
        </environment>
    </environments>
</configuration>

Service Layer Implementation

@Service
public class UserServiceImpl {
    
    @Autowired
    private UserMapper userMapper;
    
    public void executeQuery() {
        System.out.println(userMapper.selectData());
    }
}

Mapper Interface Definition

public interface UserMapper {
    @Select("SELECT 'sample_data'")
    String selectData();
}

Custom FactoryBean Implementation

@Component
public class MapperFactoryBean implements FactoryBean<Object> {
    
    public Object getObject() throws Exception {
        return Proxy.newProxyInstance(
            getClass().getClassLoader(),
            new Class[]{UserMapper.class},
            (proxy, method, args) -> {
                System.out.println("Executing: " + method.getName());
                return null;
            }
        );
    }
    
    public Class<?> getObjectType() {
        return UserMapper.class;
    }
}

Phase 2: MyBatis Proxy Integration

Enhanced FactoryBean with SqlSession

@Component
public class EnhancedMapperFactory implements FactoryBean<Object> {
    
    private SqlSession sqlSession;
    
    @Autowired
    public void configureSession(SqlSessionFactory sessionFactory) {
        sessionFactory.getConfiguration().addMapper(UserMapper.class);
        this.sqlSession = sessionFactory.openSession();
    }
    
    public Object getObject() throws Exception {
        return sqlSession.getMapper(UserMapper.class);
    }
    
    public Class<?> getObjectType() {
        return UserMapper.class;
    }
}

Application Configuration

@Configuration
@ComponentScan("com.example")
public class AppConfig {
    
    @Bean
    public SqlSessionFactory sqlSessionFactory() throws IOException {
        InputStream configStream = Resources.getResourceAsStream("mybatis-config.xml");
        return new SqlSessionFactoryBuilder().build(configStream);
    }
}

Database Driver Dependency

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.17</version>
</dependency>

Testing the Integration

public class IntegrationTest {
    
    public static void main(String[] args) {
        ApplicationContext context = 
            new AnnotationConfigApplicationContext(AppConfig.class);
        
        UserServiceImpl service = context.getBean(UserServiceImpl.class);
        service.executeQuery();
    }
}

Tomcat Architecture Overview

Core Components and Request Procesing

Tomcat's architecture consists of Connector components handling network communication and Container components managing Servlet lifecycle. The request processing pipeline involves protocol hendlers, adapters, and multiple container levels (Engine, Host, Context, Wrapper).

JSP Compilation Process

Jasper engine compiles JSP files into Servlet classes during runtime. The compilation involves parsing JSP syntax, generating Java source code, and compiling to bytecode. Pre-compilation options are available for performance optimization.

Server Configuration Elements

Key configuraton files include server.xml for core server settings, web.xml for application deployment descriptors, and context.xml for context-specific configurations. Connector configurations support various I/O models and protocols including HTTP/1.1, AJP, and HTTP/2.

Tags: Spring Framework MyBatis Dependency Injection ORM Integration Tomcat Architecture

Posted on Mon, 31 Aug 2026 16:19:47 +0000 by kiwiwilliam

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