Java Advanced Interview Impressions

Recently quit, face a few Java senior post, deep feeling, hereby write a blog record.

Impression 1: Long time no interview, many of the concept of things are forgotten, the first few interviews good embarrassment, words are not clear.  Later, after several times in the heart, I began to leisurely. The specific interview question is actually not much difficult, at the end I will give these days interview research point.

Impression 2: Before the company too comfortable, although usually also read, but not the sense of crisis, see very casual, fortunately, this separation found their own shortcomings.

Impression 3: Originally very afraid of the interview, and then thought, you go to others interview, equivalent to free examination, is the review of their own technology, or free, and a lot of interview my husband is very good, this several interviews many interviewers also gave me a lot of advice, my help is also relatively large. and can obtain the external current mainstream technical frame, expands the field of vision, can say the benefit is many.

The next part of the interview I am the main question, this face for four days, about more than 10 companies, in fact, the test centers are similar:

1:java base, mainly includes multi-threading, JVM, container. There is also the possibility of a hybrid test, multi-threading mainly from the beginning to investigate, including multi-threaded running state, the visibility of threads, CAs and implementation methods, locks, lock optimization, thread creation method, threads pool.

The JVM includes heap memory allocations, several types of garbage collector, Java memory models, and JVM tuning. This feeling asked less, may be my answer is not good enough, so did not ask in-depth.

The container mainly examines the interface of the container, ask HashMap more, hashmap How to solve the hash conflict, put operation of the process, why the thread is not safe, Hashtable and Currenthashmap different,

2: Database, mainly in database middleware, database design specifications, database paradigm and anti-paradigm application, database optimization, index

Database middleware mainly to understand the principles, it is best to use their own.

Design specifications are mainly table structure, field naming, redundancy design, sub-database sub-table, naming conventions, annotations and the like

Database optimization is complex, there are index optimization, index usage scenarios, index invalidation scenarios, index creation note points, index types, and if the data structure is good, you will be asked to say B + Tree related operations. Slow log query analysis, sub-database sub-table.

Index may be alone to ask, there is a lot of content, it is recommended to query the relevant information to supplement, after all, this piece is still quite important.

3:nosql, this piece of Redis is much more, so you can focus on the structure of Redis and the internal implementation, REDIS security, Cache elimination policy, the principle of redis implementation, the operation of Redis in the case of concurrency, caching potential problems (cache avalanche, cache and Cache avalanche), how to ensure cache consistency (cache update routines)

4: Work experience of the project, characteristics, difficulties, technical highlights. If you are refactoring, what do you do, why, and what is the benefit.

The above four parts are basically required to ask, the rest may ask: Server security, interface optimization, project management, Linux operations, algorithms, Spring, network, JS, message middleware. So we should pay attention to the usual accumulation. In particular, the accumulation of basic knowledge, after many leaks to fill the gap, make up for a lot of their shortcomings, so feel this job-hopping is still very valuable.

　　　　　

Java Advanced Interview Impressions