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The latest 180 JAVA advanced interview topics in 2020
Due to the epidemic this year, many people stayed at home for a long time, and there was plenty of time to review and prepare for the interview. Here I have prepared a 180 latest intermediate and advanced interview questions summarized by major Internet companies and major companies to help you overcome the difficulties of the interview. Some of the interview answers are also summarized at the end of the article, so I can share it with you. Everyone is helpful!
- Length of basic data types
- reflection
- ACID
- MVC
- RPC and RMI
- Common RPC framework Dubbo
- Introduction of JSWDL Development Kit
- WEB container function
- Deep copy and shallow copy
- Pass by value and pass by reference
- Ajax
- HTTP
- HTTP1 and HTTP2
- Common programming protocols
- TCP
- 3TCP (Transmission Control Protocol) and UDP (User Datagram Protocol)
- TCP/IP
- Socket
- Thread processing flow
- Blocking I/O communication model
- NIO(new 10)
- The working principle of java NIO
- Provided in java.nio.
- The difference between 10 and NIO
- Advantages of NIO
- There are several different ways to create threads? Which one do you like? Why?
- Thread Pool
- Static condition
- A general explanation of several available states of threads
- What keywords are used to modify the synchronization method?
- Why are the stop() and suspend0 methods not recommended?
- What is ThreadLocal?
- The difference between run() and start()
- What is the difference between sleep() and wait()?
- When a thread enters a synchronized method of an object, can other threads enter other methods of this object?
- Please tell me the thread synchronization method you know
- Thread scheduling and thread control
- JMM
- What are the similarities and differences between synchronous and asynchronous, and under what circumstances should they be used? Examples
- What is thread starvation and what is livelock?
- What is the busy loop in multithreading?
- Briefly describe the similarities and differences between synchronized and java.util. concurrent.locks.Lock?
- The difference between synchronization method and synchronization code block:
- How to ensure that N threads can access N resources without causing deadlock?
- What is atomic operation
- What is volatile variable? What is the difference between volatile variable and atomic variable
- What guarantee does volatile variable provide? Can a non-atomic operation become an atomic operation?
- Can a volatile array be created?
- -A table with an ID auto-incrementing primary key. After inserting 17 records, the 15, 16, and 17 records are deleted, and then Mysql.
- Restart, and then insert- record. Is the ID of this record 18 or 15?
- What is Heap table?
- Mysq|What is the default port of the server?
- Compared with Oracle, what are the advantages of Mysq|
- Distinguish between CHAR_ LENGTH and LENGTH?
- Please briefly describe the names of the four transaction isolation levels supported by InnoDB in Mysql and the difference between each level?
- What is the usage of ENUM in Mysq|
- How to define REGEXP?
- The difference between CHAR and VARCHAR?
- What can be the string type of the column?
- How to get the current Mysql version?
- What storage engine is used in Mysql?
- What does TIMEST TAMP do on the UPDATE CURRENT_ _TIMESTAMP data type?
- What is the difference between primary key and candidate key?
- How to use Unix shell to log in to Mysq|?
- What is myisamchk used for?
- What are the method commands for MYSQL database server performance analysis?
- How to control the maximum size of the HEAP table?
- What is the difference between MyISAM Static and MyISAM Dynamic?
- What is a federated table?
- If a table has a column defined as TIMESTAMP, what will happen?
- When the column is set to AUTO INCREMENT, what happens if it reaches the maximum value in the table?
- How can I find out which auto increment was allocated during the last insertion?
- How do you see all the indexes defined for the table?
- What do the% and _ in the LIKE statement mean?
- How to convert between Unix and Mysq|time stamps?
- What is the column comparison operator?
- How do we get the number of rows affected by the query?
- Are Mysq queries case sensitive?
- What is the difference between LIKE and REGEXP operations?
- What is the difference between BLOB and TEXT?
- What is the difference between mysql fetch. array and mysql _fetch. _object?
- The three paradigms of databases?
- How do we run batch mode in mysq|?
- Where will the MyISAM table be stored and also provide its storage format?
- What are the different tables in Mysq|
- What is ISAM?
- What is InnoDB?
- Mysq|How to optimize DISTINCT?
- How to display the first 50 rows?
- How many columns can be used to create an index?
- What is the difference between NOW () and CURRENT_ DATE ()?
- What kind of objects can be created using the CREATE statement?
- Mysq|How many TRIGGERS are allowed in the table?
- What is a non-standard string type?
- What are general SQL functions?
- Explain the access control list
- Does MYSQL support transactions?
- What field type is good for recording currency in mysq|
- Under what circumstances is the MYSQL data table vulnerable to damage?
- mysq|How many tables are related to permissions?
- What kinds of locks are there in Mysq|
- Mysq|Data optimization
- MySQL keywords
- Storage engine
- database backup
- How to display the table creation statement and add fields to the table
- SQL language classification
- The difference between truncate delete drop:
- Name the storage performance and characteristics of ArrayList, Vector, LinkedList
- The difference between HashMap and Hashtable
- What is the difference between ail-fast and fail-safe?
- Data structure of hashmap
- How does HashMap work?
- When will Hashmap expand?
- How does CorrentHashMap work?
- What are the basic interfaces of the Java collection framework?
- What is the difference between HashSet and TreeSet?
- What is the underlying implementation of HashSet?
- The realization principle of LinkedHashMap?
- Why does the collection class not implement the Cloneable and Serializable interfaces?
- What is a iterator?
- What is the difference between Iterator and Listlterator?
- What is the difference between Array and ArrayList? When should I use Array instead of ArrayList?
- What are the best practices for the Java collection framework?
- The elements in the Set cannot be repeated, so what method is used to distinguish repeated or not? Is it to use == or equals(? What is the difference between them
- What are the Comparable and Comparator interfaces? List their differences.
- The difference between collection and collections
- java memory allocation
- What is the structure of the Java heap? What is the Perm Gen space in the heap?
- What is GC? Why GC
- Briefly describe the java garbage collection mechanism?
- How to judge whether an object is alive? (or how to judge GC objects)
- Two recycling mechanisms for garbage collection
- What is the basic principle of the garbage collector? Can the garbage collector reclaim memory immediately? Is there any way to proactively notify the virtual machine for garbage collection?
- What will System.gc0 and Runtime.gc0 do?
- When is the finalize() method called? What is the purpose of finalization?
- If the object's reference is set to null, will the garbage collector immediately release the memory occupied by the object?
- What is distributed garbage collection (DGC) and how does it work?
- What is the difference between a serial collector and a throughput collector?
- In Java, when can an object be garbage collected?
- Generation
- Basic concepts of Gc
- Briefly describe the java memory allocation and recovery strategy and Minor GC and Major GC
- Will garbage collection occur in the permanent generation of the JVM?
- What are the methods of garbage collection in java?
- Will there be a memory leak in java? Please describe briefly.
- java class loading process?
- Briefly describe the java class loading mechanism?
- What are class loaders and what are the class loaders?
- Class loader parent delegation model mechanism?
- What is the difference between the access modifiers public, private, protected, and when not written (default)?
- How to stop the type unchecked warning in Java?
- Abstract classes and interfaces
- What are the advantages of object-oriented software development?
- What are the definition and benefits of encapsulation?
- Definition of polymorphism?
- Definition of inheritance?
- The definition of abstraction? What is the difference between abstraction and encapsulation?
- N-tier architecture
- 3 tail recursion
- Final and static
- Can assign values to static final variables at runtime
- What are the meanings of throws, throw, try, catch, and finally
- 3The difference between GET and POST for HTTP requests
- Common commands of JSP
- What are the parsing techniques for xml? What is the difference?
- There are several forms of XML document definition? What are the essential differences between them?
- What aspects of xml technology did you use in your project? How to achieve it?
- log4j log
- What is RESTful architecture:
- What is Redis? Two sentences to summarize
- redis (pipe, hash)
- Redis implementation principle or mechanism
- Redis has two types of partitions
- Mongo DB
- Mongo DB features
- Mongo DB features
- Mongo DB applicable scenarios
- Comparison of redis, memcache, mongoDB
- What is the use of Redis? Only by knowing what features it has, can we use our strengths and avoid weaknesses when we use them, and use them for our purposes: here is a summary of the Redis database
to sum up
I interviewed many Internet companies some time ago. The interview questions collected are: Redis, multithreading, JVM, Mongo DB, HTTP, HashMap, Spring, etc. The corresponding interview site also summarized a corresponding interview answer, interested Friends please pick it up!
[20 years] 2nd edition: Dachang interview questions, 143-page test book, 180 Internet enterprise interview documents, friends who are interested in one-click triple connection, see the picture below and add a small assistant VX (gyhycx7980) to receive it for free To!
A full set of 143 page test collections
[20 Years] Second Edition: Interview Questions from Dachang
[20 years] 2nd edition: Dachang interview questions, 143-page test book, 180 Internet enterprise interview documents, and friends who are interested in one-click triple connection, see the picture below and add a small assistant VX (gyhycx7980) to 100 % Free to receive