What will java interns do when they first arrive at the company, and how demanding is it?

For interns, in fact, many companies are not very demanding. After all, the requirements for you should be suitable for your salary level. Many companies must know your general level and don't expect too much. They just let you work while studying. If you are smart enough and diligent enough, you may get more training.

However, different levels of companies (BAT & gtTMD & gt other excellent Internet companies > small start-up companies) must have different training levels for you, and the corresponding requirements for your internship must also be different. Don't think that the higher the demand for you, the higher the internship salary. No, companies like Tencent Ali have high technical requirements for interns, and the salary is about two or three thousand, but the future development is far greater than this value.

I. Requirements of BAT enterprises for interns (represented by Ali):

Java foundation is very important, of course, we should also deeply understand the principles, such as JVM, JMM, Classloader, and the source code of some commonly used classes. You can try to analyze it yourself. Now I want you to tell me the internal implementation of LinkedList. Needless to say, HashMap will be asked in 80% of the interviews. There are also important, multithreading, concurrency, network, IO. These are all to see! In particular, the source code of spring should be read well, and the architecture inside is very well designed!

The technical knowledge to be mastered is summarized as follows:

1, operating system. Especially in memory/threads/processes.

2. Computer network protocol, with emphasis on TCP/UDP/HTTP.

3. Data structure and algorithm.

4. Database, understand the implementation mechanism of index in mysql storage engine, several granularity of database transaction, row lock and table lock; Optimistic locking, pessimistic lock, etc.

5, design patterns, familiar with several commonly used design patterns.

6.Java language foundation. Familiar with java language foundation, JVM and memory model, focusing on object-oriented, collection framework (inheritance relationship, implementation principle), exception system, IO system, concurrent collection and multithreading. Familiarity with multithreading programming/concurrency/thread safety can obviously add points.

7, J2EE, familiar with Spring/Spring MVC, ORM, etc. After reading the source code and understanding the principle, you can obviously get extra points.

8.linux, just be familiar with the basic Linux commands.

9. If you have an internship project that you have done, you will get many points.

Requirements of TMD enterprises for interns (represented by Meituan);

1, proficient in Java/C++/golang programming (at least one subject)

2. Familiar with background service development and network development under linux.

3. Familiar with open source projects such as zookeeper and redis is preferred.

4. Experience in R&D distribution and service consistency is preferred.

5. Excellent communication and coordination skills and project promotion ability.

Other excellent Internet companies (represented by Netease)

1, with solid basic skills such as computer science, database, network and operating system. , and a deep foundation of Java programming.

2. Familiar with common design patterns and have solid basic skills in computer science, database, network and operating system. , and have a deep foundation of Java programming, familiar with common design patterns.

3. Proficient in mainstream open source framework design concepts, and have a deep understanding of Spring and Mybatis;

4, master the principle of database, design and development based on Oracle or Mysql.

5. Familiar with Linux operating system, git, maven and other tools.

6. Strong logical analysis, data analysis and problem solving skills;

Other small internet companies have different requirements for interns according to their own development direction, and need specific analysis of specific problems. Of course, the same thing is: we must lay a good foundation in basic knowledge and know some computer basics.

In fact, some of the above skills are a bit out of line (for interns). Don't be stressed, just master six or seven points. Don't be frightened by these recruitment requirements. Many of them are very demanding. Of course, if you happen to know that's your advantage, right?