Java architecture train --Java the basis of the interview test sites list

basis

1. Strong, weak, references, virtual references, soft references
2. The role of final keyword (methods, variables, class)
3. Generics, generics inheritance, generics erased
4. jdk ServiceLoader
5. LinkedList、LinkedHashMap、LRU
6. Decorator Pattern Proxy mode, the chain of responsibility pattern, plant pattern, adapter mode, the builder pattern, singleton, template mode, observer mode ...
7. About loss of accuracy problems: int, long exceed the maximum
8. Common types of meta-annotation methods, inheritance java.lang.Annotation, foundation type annotations, annotation: About notes
9. About ClassLoader, class loader delegation model parents

J.U.C

1. Parameter Description thread pool, thread pool thread recovery, shutdown
2. Lifecycle thread pool?
3. Operational processes core object model Worker thread pool is like?
4. Reject the policy of the thread pool which has four kinds?
5. Thread pool submission, execute and submit What is the difference? In the actual development of what issues need attention?
6. threadlocal principle, the data structure
7. Concurrent collections classes to know what?
   • ConcurrentHashMap
   • CopyOnWrite set of principles, the lock mechanism
   • ConcurrentLinkedQueue、LinkedTransferQueue、ArrayBlockingQueue、PriorityBlockingQueue、SynchronousQueue、DelayQueue
8. AQS principle:
   1. Exclusive & Share
   2. state & CHL queue
9. lock:
   1. Synchronized、ReentrantLock、RWLock、Condition、LockSupport、StampedLock、
   2. The concept: CAS spin, re-entry, bias
10. volatile：
    1. Multithreading Share & stop instruction reordering
    2. The escape analysis jvm & Tlab & eliminate false sharing & UNsafe &
11. atomic:
    • The disadvantage of CAS, spin, ABA problem
12. atomic 原子性、Reference、referenceArray、longadder

jvm virtual machine

1. Virtual machine memory model
2. New Generation (Eden S0 S1), the old years, MetaSpace (ratio)
3. Garbage collection algorithm (reference count, the compression flag, cleared replication algorithm, partition), the garbage collector
4. GC pauses, throughput, into the threshold of the old era, large object recycling issues
5. jvm tuning parameter settings
6. Commonly used commands: jstat, jmap, jstack etc.
7. Memory Overflow Analysis: within the pile, heap outside (meaning, how to set up)
8. CPU soared: deadlock, thread blocks
9. About GC: minor major full
   • stw, security points, etc.

Data Structure & Algorithms

1. Arrays, linked lists, trees, queues ...
2. About time complexity, time for space conversion case
3. About sort, bubble, fast discharge, recursive, binary search, Bitwise

Spring

1. Spring life cycle process of combing
2. Spring extension point role
3. Spring IOC AOP basic principles
4. Dynamic Proxy
5. BeanPostProcessor role?
6. ApplicationContextAware role and use?
7. BeanNameAware and BeanFactoryAware the order?
8. InitializingBean and BeanPostProcessor the method after the order?
9. ApplicationListener monitor the Application event What?
10. Spring concept module assembly, such @EnableScheduling @EnableRetry @ EnableAsync, @ Import annotations role?
11. ImportBeanDefinitionRegistrar extension point to do something?
12. ClassPathBeanDefinitionScanner role?
13. NamespaceHandlerSupport namespace extension point of action?
14. How to inject a dynamic Bean?
15. How to Class custom annotation where the initialization is injected into the Spring container?
16. BeanDefinition refers to what is the difference between the BeanDefinitionHolder, Spring BeanDefinition examples of how to save?
17. ASM and CGlib
18. Spring assembly conditions, automatic assembly

RPC communications framework

Dubbo

1. Dubbo's Spi mechanism?
2. Dubbo core model invoker, invocation, filter
3. Dubbo implicit transfer?
4. Dubbo generalization call?
5. Dubbo's export and importer opportunity?
6. Dubbo service call process?
7. Dubbo load balancing strategy?
8. Dubbo cluster fault tolerance?

Telecommunication

IO / NIO

1. IO NIO Ku别?
2. Multiplexing concept, Selector
3. Channel concept, the concept of Bytebuf, flip, position ...
4. FileChannel How to use?
5. RAF use, seek, skip method

Netty

1. Reactor Netty about implementation?
2. Netty's ByteBuf What?
3. Memory and non-memory Bytebuffer difference and usage scenarios?
4. Pooled and non-pooled buffer difference and usage scenarios?
5. About Netty request and response Buffer Buffer?
6. Netty's ChannelPipeline design patterns?
7. Netty's core option parameter configuration?
8. Netty's ChannelInboundHandlerAdapter and SimpleChannelInboundHandler relationship?
9. EventLoop core Netty achieve?
10. What common methods (ChannelDuplexHandler) Netty connection event management interfaces?
11. Netty codec serialization means
12. Netty's FastThreadLocal achieve?
13. Netty applied in decorative patterns and observers reflected Where?

MQ

1. API use, common production and consumption model, to build a cluster architecture
2. FAQs, message delivery reliability, power and other safeguards
3. Concepts, principles, memory, message delivery, communication mechanisms, performance-related optimization
4. MQ act on the common purpose of serving decoupling, load shifting, etc.

RocketMQ
Kafka
RabbitMQ
ActiveMQ

Cache

1. Memory Cache
2. External heap memory cache recovered released
3. Cache penetration, avalanches, Hot Key, big Key, bottomless pit problem, update the cache and elimination, the database cache coherency

Redis

1. Redis idempotency
2. Redis distributed lock to achieve
3. The atomic Redis, features Redis
4. Redis cluster related issues, consistency hash, slot and other concepts
5. What is Redis?
6. .Redis data types?
7. What are the benefits of using Redis there?
8. Redis Memcached What are the advantages compared to?
9. Memcached and Redis difference between what are?
10. Redis is single-threaded single-process it? Why is it so fast so efficient?
11. A value of type string can store the maximum capacity is how much?
12. What persistence mechanism Redis is? Their advantages and disadvantages?
13. Redis common performance problems and solutions What?
14. Redis expired key deletion policy?
15. Redis recovery strategy (phase-out strategy)?
16. Why Redis need to put all the data into memory?
17. Redis synchronization mechanism to understand it?
18. Pipeline What are the benefits, why use Pipeline?
19. What ever used Redis cluster, the cluster is the principle?
20. Redis clustering solutions under what circumstances would cause the entire cluster is unavailable?
21. Redis supports Java client what are? Official recommended to use which?
22. Jedis Redisson contrast with what advantages and disadvantages?
23. How Redis set a password and verify password?
24. Talk about the concept Redis hash slot?
25. Redis cluster master is how to copy from a model?
26. Redis cluster will write to lose it? why?
27. How to between Redis cluster is replicated?
28. The maximum number of cluster nodes Redis is how much?
29. How to select a database Redis cluster?
30. How to test the connectivity of Redis?
31. How to understand Redis affairs?
32. Redis transaction-related commands and which of?
33. Redis key expiration time and permanent, respectively, how to set?
34. How do Redis memory optimization?
35. How Redis recovery process work?
36. What are ways to reduce memory usage Redis it?
37. Redis memory runs out what will happen?
38. Redis instance of a maximum number of keys can be stored? List, Set, Sorted Set how many elements can be stored up to them?
39. There 2000w MySQL data, Redis data store only 20w, how to ensure that the data is hot data in Redis?
40. What Redis most appropriate scene?
41. If there are 100 million Redis key, which has a key 10w begins with a fixed known prefix, if all of them to find out?
42. If a large number of key needs to be set at the same time has expired, the general needs attention?
43. Used Redis what to do asynchronous queue, how do you use?
44. Used Redis distributed lock it, which is what's going on?
45. How to prevent caching penetrate the avalanche?

Mybatis

1. What is the difference in mybatis # {} and {} $ is?

2. There are several ways mybatis page?

3. RowBounds are all one-time query results? why?

4. What is the difference mybatis logical page and physical page is?

5. mybatis support lazy loading? What is the principle of lazy loading?

6. Mybatis talk about the cache and secondary cache?

7. Mybatis and hibernate difference of what?

8. What actuator (Executor) mybatis there?

9. What The principle mybatis pagination plug-in is?

10. mybatis how to write a custom plug-in?

Other technologies

Hystrix
the Sentinel
availability service middleware
the Zookeeper / Curator
the Nginx
Haproxy
the LVS
Haproxy
database stores schedule &
Sharding the JDBC-
ElasticJob
scheduling related internet: DAG, airflow and other
search relevance
ELK, database accelerator, the master search (algorithm)
Logback, Slf4j2

Solr & Lucene