Java Surface question Set (i) List of questions

Java Basics:

1.1. Java Basics

(1) Object-oriented features: inheritance, encapsulation, and polymorphism

(2) The difference between final, finally and finalize

(3) What are the similarities and differences between Exception, Error, runtime anomalies and general anomalies

(4) Please write out 5 common runtime exception

(5) What is the difference between int and integer, the value cache range of integer

(6) Packing type, packing, unpacking

(7) String, StringBuilder, StringBuffer

(8) The difference between overloading and rewriting

(9) The difference between abstract classes and interfaces

(10) Talk about the use and realization of reflection

(11) Talking about the scene and implementation of custom annotations

() The difference between the get and post methods of an HTTP request

() the difference between session and Cookice

(14) List your favorite JDK packages

(a) MVC design ideas

(a) The difference between equals and = =

The difference and connection between hashcode and Equals method

(18) What is Java serialization and deserialization, and how is Java serialization implemented? or please explain the role of the Serializable interface

(+) methods commonly used in the object class, why wait notify is placed in object?

How does Java's platform independence manifest itself?

(+) The difference between JDK and JRE

What are the new features of Java 8

1.2 Common collections for Java

(at) The difference between list and set

Link to set and hashcode and the Equals method

The difference between list and map

(ArrayList) difference from LinkedList

(ArrayList) difference from Vector

(HashMap) The difference between the Hashtable and the

The difference between HashSet and HashMap

(a) The difference between HashMap and Concurrenthashmap

(HASHMAP) Working principle and code implementation, when to use the red and black trees

(32) The problem of HashMap dead loop in multi-threaded condition

(HASHMAP) Hash Dos attack problem

How the Concurrenthashmap Works and code implementation, how to count all the number of elements

1.3 Processes and Threads

(35) Concepts of threads and processes, parallel and concurrency concepts

(36) How to create threads and implement them

(37) Inter-process communication mode

(38) Talk about Countdownlatch, cyclibarrier principle and difference

(39) Talk about semaphore principle

(40) Talk about exchanger principle

ThreadLocal principle Analysis, why the ThreadLocal appeared oom, the deep-seated principle

(42) How to implement the thread pool

(43) How the thread pool is implemented

(44) The life cycle of the thread, how the state is transferred

1.4 Locking mechanism

(45) Talk about thread safety, what is thread safety, how to ensure thread safety

(46) The concept of re-entry lock, why can the re-entry lock prevent the deadlock?

(47) How to check for deadlocks (check for deadlocks via Jconsole)

() volatile implementation principle (Prohibit command reflow, flush memory)

(synchronized) Implementation principle (Object monitor)

(a) The difference between synchronized and lock

(Wuyi) AQS synchronization queue

CAS unlocked concept, optimistic lock and pessimistic lock

(53) commonly used atomic operations

(54) What is the ABA problem and how does the ABA problem solve?

(55) Optimistic locking business scenarios and implementation methods

($) Common concurrency classes under Java 8 concurrent Packages

(57) The concept of biased lock, lightweight lock, heavyweight lock, Spin lock

1.5 JVM

(+) Memory partitioning of the JVM runtime

(59) example and cause of memory overflow oom and stack overflow SOE, how to troubleshoot and resolve

(60) How to determine if an object can be recycled or survived

(61) Common GC recovery algorithms and their meanings

(62) Common JVM performance monitoring and Troubleshooting tool classes (JPS, Jstat, Jmap, Jinfo, Jconsole)

() How the JVM sets parameters

(+) JVM Performance tuning

(65) class loader, parental delegation model, life cycle of a class, how classes are loaded into the JVM?

(66) class loading process (load, validate, prepare, parse, initialize)

(67) Strong references, soft references, weak references, virtual references

(JMM) Java memory model

1.6 Design Patterns

(69) Six principles of design patterns and their meanings

(70) Common singleton mode, the advantages and disadvantages of the realization method

What design patterns are used in spring

(mybatis) Design patterns used in the

(73) Design patterns used in common open source frameworks

(74) Agent mode, Factory mode

1.7 Network and I/O fundamentals

(Bio,nio,aio) The concept of

(76) What are long connections and short connections

What is the difference between Http1.0 and 2.0?

(+) The concept of HTTPS

(79) Three-time handshake and four-time wave concept

Write down the questions that you may be asked about in the interview, and post the answers and answers later.

Question List of Java polygons (i)