Java Interview Summary (2017.10)

Source: Internet
Author: User
Tags rounds volatile mysql index spark rdd

Java Interview Summary (2017.10)

Summarize your interview experience for the last one months. During the interview big Data and Java, the following mainly for Java roughly summarized.

A drop (routines: projects, data structures, algorithms, databases, multithreading)

1. Handwritten list inversion, binary lookup (ordered loop array 4 5 1 2 3)

2.mysql index, which places affect performance?

Changes in 3.jdk1.8 HashMap? Array + tree, array plus table space complexity

4.hashmap structural optimization?

5.concurrenthashmap mechanism?

6.hbase, why do you have a column family?

7.RABBITMQ, Redis-related?

8. Company Project structure (I told the module I am responsible for)

9.spark Rdd?

10. Memory model, memory management, GC?

11.js how objects are created (not many)

12. Database engine, index, where IO is involved, how to optimize?

13. Design cleanup mechanism, Redis set expired values, how to clean up?

14.redis storage type?

15.SPRINGMVC execution process, MyBatis level two cache, caching mechanism?

16.zookeeper election mechanism?

What are the components of 17.spring core?

18. Database isolation mechanism Dirty read Magic read?

19. Locking mechanism?

What is the difference between 20.synchronized (sort) and lock (no sorting, high throughput)?

21.volatile visibility?

22. Multithreading implementation method, constructing method parameters

Second, some East (routines: project, frame composition, high concurrency, JVM, database)

1. Self-Introduction

2. Draw the architecture diagram of the most familiar project talk about the process

3. According to the details of the process to achieve

4. Several ways to implement concurrency security your implementation scenario at work synchronization mechanism


Methods in the 7.Object method

8.ThreadLocal mechanism

9. What happens when static and common methods in a class are modified with synchronized

10. How to solve the problem of HashMap deadlock in concurrent

11.Hashtable Replacement HashMap

12.collections.synchronizedmap Wrap the HashMap.

13.ConcurrentHashMap Replacement HashMap

How the 14.JVM memory model JVM handles string str = new String ("abc")

15.GC mechanisms and algorithms (when to trigger full GC, etc.)

16. A talk about recently read technical books

17. Server/Database high concurrency/High availability solution

18. Describe a typical write operation process create several classes how to increase the maximum concurrency for MySQL write operations

19. Optimization of Queries

20. How to ensure the consistency of read and write data under high traffic volume

21. Considerations when creating a table when redundant design is required

22. Which fields to index the pros and cons of building multiple indexes on the same table

23. Which of the most difficult algorithms have you studied?

Use of regular in 24.Nginx

What's in the 25.Springmvc? What does spring AOP bottom do?

26. Dynamic Proxy, Reflection

What 27.http status code 302 stands for

What is included in the 28.cookie request header

29. How to save user data without session

30. Why a double check is required for a single case

Types of 31.js Objects JS How to implement the map structure

Summary: 3 consecutive rounds of interview without a written exam for working experience will ask details specific to code implementation

Three, a meter (routines: multithreading, data structure, algorithms, databases, Linux)

1. Fence (cyclic), latching \ Descending lock (Countdownlatch)

2. Multi-threading, 5 states, multithreaded method parameters (number of core thread pools, maximum number, timeout, time unit, deny server Assistant (handler, queue))

3.hashmap source Code, parameters

4. Complexity of space and time

5. Two threads, Output 1, 2, respectively. How to implement 1,2,1,2,1,2, ... Swap output

6. Two-point query, return subscript,

7. Quick Sort

8. databases, indexes,

The difference between 9.flume and storm

10.redis How to save set\list equivalent

11.volatile function

12. Pessimistic lock, optimistic lock in what situation

13. How to achieve the second kill

14. Three-dimensional array assignment, three-layer for loop, with a loop?

15.linux querying the IP of a file

16. Find out if all the files in the directory contain a string

17.linux query command by keyword

18. The last 5 lines of the output log tail-f 5./log

The final summary: The above list of three companies interview (two years of work experience), the interview problem is similar, the old. The interview usually takes about 2 hours, and the longest I experience is 3 and a half hour. Interview is usually a triple (two rounds of technical side, a round of HR), the most experienced interview is four rounds (technical plane, round HR face). Large companies pay more attention to the foundation, such as: Data structure, algorithm, index, JVM, optimization, etc., small companies more emphasis on applications, such as: Spring, struts2, MyBatis, database and other uses.

Java Interview Summary (2017.10)

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