OS business group interview (Ali), OS business interview ali

OS business group interview (Ali), OS business interview ali

Senior Java R & D Engineer interview questions:

1) based on your resume, which project is most impressive?
No score, but based on the resume, determine the main coverage of subsequent problems. Score: 1-5
2) What is the architecture design of this project? Which systems, deployment environments, and the entire function and data flow are available?
The ability to fully state system functions, deployment environment, and data flow. Score: 1-5
3) what technologies are used in this project? Why are these technologies used?
Clearly state the technologies and frameworks used and understand the purpose of using these technologies. Score: 1-5
4) What are the advantages and disadvantages of these technologies discovered during implementation? How can we make full use of the advantages and overcome the disadvantages?
The advantages and disadvantages of these technologies are clearly defined, the scenarios where advantages are applied, and solutions for overcoming and bypassing disadvantages are clearly described. Score: 1-5
5) after the project is completed, what problems do you think the original design has and what improvements should be made?
Have you reflected on the architecture design, have you ever thought about the rationality of some technologies, have you considered re-selection, and have you analyzed the improvements andThe reason for replacement.
Interview Questions:

1. Describe a system, function, design, and implementation

2. team structure and responsibilities

3. Why don't I use a technology?

4. Are clusters used in applications? How large is it?

5. "problems encountered in cluster applications, session sharing problems? "

7. How to implement clusters? Session replication? Stateless? Centralized session?

8. What is the difference between Collections and Collection?

9. Differences between HashMap and HashTable

10. interfaces of the Set in Java

11. What is the relationship between Map and Collection?

12. How does ClassLoader find classes?

13. Differences between equals and =

14. "Exception, checked, unchecked"

15. exception mechanism, hierarchy

16. Use of final keywords

17. Role of the hashCode () method

18. Differences between InputStream and Reader

19. Differences between interfaces and abstract classes

20. Java non-blocking I/O?

21. What are the basic Object methods of Java?

22. "What is the reflection performance in Java? What do you think "?

23. is the calculation of the hashCode () of an Object unique?

24. classloader structure of typical web applications

25. "What interfaces do I need to implement to sort objects"

26. Under what circumstances will you use serialization in your JAVA code?

27. How to ensure that non-static methods of a class are synchronized across multiple instances?

28. How to convert a String to an int

29. How to serialize a class instance

30. How to clone a class

31. How do I identify an attribute in a JavaBean object that does not need to be serialized?

32. What are the memory optimization parameters in Java?

33. What is garbage collection? Why? How can it work?

34. ajax

35. cookie & session

36. cookie principles

37. Differences between forward and redirect in http

38. Structure of classloader in the ear Application

39. What transaction attributes does EJB have (TransactionPropagationAttributes )? Describe the differences between them.

40. What kinds of message models does JMS have?

41. lifecycle of stateful session bean,Describe the lifecycle of StatefulSessionBean in detail.

42. "In an EJB container, how does the container know that the transaction has been completed and can be committed? How do users control transaction rollback? "

43. Meanings and uses of AOP

44. What are the meanings and purposes of Ioc? What are the benefits of using IoC? What are the most popular IoC containers?

45. functions used by Spring

46. Process for processing requests in Structs

47. springaop, transaction, FactoryBean & BeanFactory

48. Do you usually pay attention to the development of open-source software?

49. Methods in the HttpServlet class

50. What is the problem if jsp is widely used during jsp execution? PermGen size

51. servlet Lifecycle

52. session Lifecycle

53. How can I clear the resource usage of the object saved in HttpSession when the HttpSession expires?

54. What is the method corresponding to policy?

55. What is the meaning of the daemon thread? What does it mean?

56. What is the difference between the sleep method of Thread and the wait method of Object?

57. Explanation of synchronized

58. Explanation of ThreadLocal

59. How to stop a running thread?

60. What is thread security? Is the servlet thread safe?

61. How to Write a thread? What are the points of attention when using a thread?

62. How does JDK implement XMLParser and it has nothing to do with interfaces? How does jdk find the implementation of XMLParser? How can I overwrite the XMLParser implementation in jdk1.4?

63. xml Parsing Model Description?

64. Performance Test and capacity test? How to do it?

65. Is there any design tailored to scalability? Is there any performance-oriented design? Scalability and extensibility

66. What are common sorting algorithms? What are their advantages and disadvantages?

67. List Design Patterns and explain application scenarios

68. PreparedStatement and Statement

69. What isolation levels does database transactions have? Please elaborate separately

70. Database-related performance optimization? SQL, database itself, cache?

71. How to solve the problems encountered in the project?

72. What aspects should I start with when optimizing java application performance?

73. What is the native method? What are the features of transient variables? Volatile keyword usage?

 

74. How many objects are generated for Integer [] I = {1337,424 242} and int [] I = {1337,424 242? That has better performance. Why? Is float f = 3.4 correct?

75. What are the differences between ThreadLocal and InheritableThreadLocal?

76. Does swtich work on byte (YES), long (NO), and String (No )?

77. System. out. println (3*0.1 = 0.3); what is the output?

78. How does java implement multi-inheritance? Write a thread-safe Singleton?

79. What is the difference between Runnable and Callable in Java?

80. In what scenarios will FutureTask be used? What scenarios does ReadWriteLock use?

81. What is the internal storage structure of ArrayList, LinkList, and HashMap?