Framework

1. Usage 2. Source analysis 3. References

1. JSR 269 2. Principle

Why MyBatis exists and its execution flow

What Spring Cloud is and a reference.

Spring interview questions with detailed answers; how Spring resolves circular dependencies.

Spring + auto-configuration, a framework for quickly starting projects.

Spring MVC components and request-processing flow.

1. What it is 2. Usage 3. Source analysis 4. Summary 5. References

Create a Maven project, configure MyBatis, create the mapper, test it, and inspect the project structure

Spring core container, data access/integration, Web, AOP, Instrumentation, Test, and miscellaneous modules.

20 Spring Boot interview questions - Java Technology Stack - SegmentFault.

Create a Spring MVC project in two ways, configure Maven and Spring MVC, add controllers/JSP/HTML, configure Tomcat, and run the project.

Framework layers, four core objects, SqlSessionFactory configuration parsing, SqlSession and Executor creation, mapper proxy creation, CRUD execution, mapped statements, first-level and second-level cache, and JDBC execution.

Breakpoint call stack, servlet class relationships, DispatcherServlet loading, request dispatch, HandlerMapping, HandlerAdapter, handler invocation, and view rendering.

Reference: MyBatis interview questions

Thread-safety issues caused by Spring MVC singleton beans, solutions, and a reference.

Common Spring MVC interview questions with detailed answers - CSDN Blog.

1. Create the project 2. pom.xml 3. Code

1. Overview 2. Boss-array initialization 3. Worker-array initialization 4. Bind

What Apollo is, how to use it, and how its push-pull configuration update mechanism works.

1. What it is 2. Usage 3. Principles 4. Problems 5. References

What Feign is, why it exists, and how its interface proxy, Ribbon, Eureka, and HTTP request construction work.

What Spring Cloud Gateway is, its Route/Predicate/Filter concepts, and its asynchronous non-blocking thread model.

1. What Hystrix is 2. Why Hystrix is needed 3. Usage 4. Features 5. Principles 6. References

What Ribbon is, why load balancing is needed, usage, working flow, and load-balancing strategies.

What Spring Cloud Sleuth is and how it works with Zipkin.

1. What it is 2. Usage 3. Principles 4. Zuul 1 vs Zuul 2 5. References

1. What ApplicationListener is 2. How to use the event-listener mechanism 3. References

1. Scope categories 2. Why prototype exists 3. References

1. Create the project 2. pom.xml 3. Code

1. Create the project 2. pom.xml 3. Code

Class inheritance diagram and principle analysis of Spring's AutowiredAnnotationBeanPostProcessor.

1. Enable transaction management. 2. TransactionManagementConfigurationSelector imports AutoProxyRegistrar and ProxyTransactionManagementConfiguration. 3. Study AutoProxyRegistrar. 4. Study ProxyTransactionManagementConfiguration and transaction interception.

Two questions behind a custom Spring Boot starter and a complete hello-spring-boot-starter example.

Create a project, configure pom.xml, and use Spring Boot caching with Application, TestController, and TestService.

1. Experiment. 2. Structure of an executable Jar. 3. How the program entry point is found. 4. Jar packages that can start without the java -jar command. 5. Reference.

How Spring Boot enables MyBatis auto-configuration and how AutoConfiguredMapperScannerRegistrar determines which package to scan for @Mapper interfaces.

1. Auto-configuration classes pre-imported by spring-boot-starter-web. 2. How custom configuration takes effect. 3. Why @EnableWebMvc disables Spring Boot MVC auto-configuration. 4. Reference.

Create a project, configure pom.xml, and write Application.java.

1. Enable ServletContainer auto-configuration. 2. Inject the Tomcat container factory. 3. How custom configuration takes effect. 4. How to modify Tomcat configuration. 5. Summary.

Netty learning resources

Historical Netty source-analysis summary diagrams

Why thread isolation is needed, isolation modes, and thread-pool versus semaphore isolation.

1. Process 2. Usage 3. References

1. What AOP is 2. Implementation principle

1. Explanation of IoC 2. Implementation principle 3. Benefits of IoC

Common Spring annotations and Aware interfaces, including Configuration, ComponentScan, Bean, Scope, Lazy, Conditional, Import, Value, Autowired, Qualifier, Primary, and Profile.

1. What transaction propagation is. 1.1. Propagation behaviors including REQUIRED, SUPPORTS, MANDATORY, REQUIRES_NEW, NOT_SUPPORTED, and NEVER. 1.2. Notes. 2. References.

How the cache manager and cache classes are generated, how cache proxy classes are generated, and the overall execution flow.

1. What it is 2. Components 3. Processing flow 4. ChannelPipeline

1. What off-heap memory is 2. NIO off-heap memory 3. Netty off-heap memory 4. References

1. BeanFactory and ApplicationContext 2. References

Create a project, configure pom.xml, and use Spring transactions with DbConfig, TestService, and TestDao.

1. What a circular dependency is 2. What problems it causes 3. How to solve it 4. References

1. Use @DependsOn 2. References

NioEventLoopGroup class hierarchy, constructor chain, initialization of selector/select strategy/rejection policy, EventLoop count, executor, child EventLoops, and chooser.

1. Code to analyze 2. Create ServerBootstrap 3. Set ServerBootstrap properties 4. ReflectiveChannelFactory

1. Code to analyze 2. Server binds the port

1. Set a breakpoint 2. New connection enters

1. When pipeline is created 2. What pipeline looks like 3. Tail and Head

bind, channelFactory, and creation of NioServerSocketChannel

1. Code to analyze 2. Create ApplicationContext and trace the refresh process

1. Start Spring Boot. 2. Process of creating SpringApplication: determine web environment, load ApplicationContextInitializer and ApplicationListener instances, save the main configuration class, and run the application.

1. Code to analyze 2. Create the thread factory 3. Create the executor

1. Code to analyze 2. NioSocketChannel constructor

1. Add a handler 2. Remove a handler

Call path and ServerBootstrap.init

1. Code to study 2. Process BeanDefinitionRegistryPostProcessors 3. Process BeanFactoryPostProcessors

1. Enable Spring Boot auto-configuration. 2. Inject AutoConfigurationImportSelector into the container and import auto-configuration classes from META-INF/spring.factories. 3. Summary. 4. Reference.

1. Code to analyze 2. Parameters passed to NioEventLoop 3. NioEventLoop is a single-threaded thread pool 4. Constructor

1. Code to analyze 2. Propagate through the pipeline 3. Pass through ServerBootstrapAcceptor 4. Analyze channelRead

Call path and event-loop registration

1. Code to study 2. Obtain BeanPostProcessors 3. Classify them 4-7. Register each group

1. Code to analyze 2. Set a breakpoint and connect with nc 3. Propagate channelActive 4. Reach HeadContext 5. Read through AbstractUnsafe

Call path, AbstractBootstrap, AbstractUnsafe, and AbstractNioChannel

Source tracing of finishBeanFactoryInitialization and preInstantiateSingletons through getBean, singleton lookup and creation, BeanPostProcessors, bean instantiation, property population, initialization, proxy creation, and destruction registration.

Historical server-startup diagram

Spring IoC UML diagram

Instantiate NioServerSocketChannel through reflection, configure it as non-blocking, and create channelId, Unsafe, and pipeline.

1. Code to analyze. 1.1. How NioEventLoop executes the Runnable. 1.2. What the bind task executed by NioEventLoop does, including JDK NIO bind, channelActive propagation, and registering interest in accept events.

1. Add handlers for the experiment 2. Start from the pipeline 3. Forward through AbstractChannelHandlerContext 4. Enter HeadContext 5-8. Traverse inbound handlers to TailContext

Data structure, API, class hierarchy, and classification

Enable AOP, register AspectJAnnotationAutoProxyCreator, and trace when ImportBeanDefinitionRegistrar.registerBeanDefinitions is called

Class hierarchy, call-stack analysis, BeanFactoryAware setBeanFactory, registration and initialization of AnnotationAwareAspectJAutoProxyCreator

Created on Monday, July 22, 2019. Source analysis of Spring AOP from @EnableAspectJAutoProxy through auto-proxy creation and target-method interceptor execution.

1. Code to analyze 2. Obtain the channel pipeline and add a ChannelInitializer

Code analysis of the NioEventLoop run loop: select, selector rebuild, selected-key optimization, processSelectedKeys, and asynchronous task execution.

1. Add handlers for the experiment 2. Start from the pipeline 3. Enter TailContext 4-7. Traverse outbound handlers back to HeadContext

ByteBufAllocator class hierarchy, AbstractByteBufAllocator, unpooled allocation, and pooled allocation

Trace postProcessBeforeInstantiation and postProcessAfterInitialization while creating singleton Beans

Select a NioEventLoop, create a ChannelPromise/Future, register the channel through Unsafe with the JDK NIO selector, and invoke handlerAdded/initChannel callbacks.

1. Prepare experiment data 2. Start debugging 3-7. Propagate the exception through handlers to TailContext

Historical example of allocating, reading, writing, and releasing a pooled direct ByteBuf

Trace to postProcessBeforeInstantiation, determine whether a proxy is needed, wrap the Bean with advisors, and create JDK/CGLIB proxies

1. Channel class hierarchy 2. Config class hierarchy

Invoke Calc.div, enter the proxy intercept method, build the interceptor chain, and execute interceptors plus the target method

newDirectBuffer, PoolThreadLocalCache, PoolThreadCache, and PoolArena

Constructor and the tiny, small, and normal MemoryRegionCache groups