First, Java basic part

1. Use the length property to get the array length

2. What is the difference between Collection and Collection

3, String s=new String(‘ xyz ‘); Several object objects are created

4, short s1;

s1=s1+1; Is there a mistake?

5. The difference between Ancient and Overloading

6. Set elements cannot be repeated.

7, Give a common Runtime exception.

8. Difference between Error and exception.

9. Whether List and Set inherit from Collection interface.

Class and interface.

Can we inherit the String class?

12. There is a return statement in the try{} finally. Will the code immediately after the try be executed and when, before or after the return.

13, the most efficient way to calculate 2*8 is what

X.qual (y)==true, x.qual (y)==true

Value passing and reference passing

16. Check whether the switch applies to byte, long, and String.

The difference between ArrayList and Vector, and between HashMap and Hashtable.

What is GC, why there is GC, a brief introduction to GC.

19, float f=3.4

20. Introduce the Collection Framework in Java.

21. Implement comparison method in Collection framework

22. The difference between String and Stringbuffer

23. Final, finally, Finalize

24, Object-oriented characteristics

Is String the most basic data type?

The difference between run-time exceptions and generic exceptions

27, ArrayList, Vector, Linkedlist storage performance and features

Heap vs. stack

The simple principle and application of exception handling mechanism in Java

30, the principle and characteristics of garbage recycling, and consider two recycling mechanisms

Name some common collection classes and methods

Describe how the JVM loads Class files

Sorting methods, understand. (Algorithms and data structures were not asked in the interview.)

Throws, throw, try catch finally represents what meaning, try block can throw an exception

35, Are there any restrictions on whether a ‘.java ‘source file can contain multiple classes?

36. There are several types of streams in Java, and the JDK provides some abstract classes for each type of stream to inherit.

Is there a memory leak in Java? Please briefly describe.

38. The difference between static and instance variables.

What is Java serialization, how to implement Java serialization.

Can non-static methods be called from within a static method?

Write clone method, usually have a line of code.

42, How to jump out of multiple nested loops in Java

43. Name 5 common classes, packages, and interfaces.

44, Java thread implementation method, with the keyword modification synchronization method.

45. The difference between synchronous and asynchronous.

Method of thread synchronization.

String common method, string into integer method, integer into string method.

Java Advanced

1. Briefly describe your understanding of object orientation and give examples of your understanding.

2. Write the singleton pattern.

3. Write a regular expression for an 11-digit mobile phone number

4, string multiple Spaces to convert a space

5, string common methods, substring(),split().

6. Difference between start() and run().

Write down the design patterns you know.

8. Introduction to Webservice. (I haven’t used this before, so it’s rubbish.)

9. Tell the life cycle of servlets and the difference between servlets and CGI.

10. The difference between sleep and wait.

What is launch and how to achieve it.

12, check the string palindrome, the number of words in English and the number of words statistics (some companies have higher requirements, the need for manual programming, Baidu to find some common interview programming questions).

13. TCP/IP three-way handshake.

14, HTTP protocol several request methods, differences.

15. Whether Ajax requests can be synchronized.

16, hide THE URL.

17. Describe the realization steps of obtaining a web page content without specific implementation process (i.e. crawler: obtaining the URL of the web page and then obtaining the web page content from URL China), and investigate the logical thinking ability.

18. Briefly describe the difference between post and GET methods in character encoding and HTTP protocol.

An HTTP request from the beginning to the end of what has gone through the process, shorthand flow chart.

Three, the framework (only introduce yourself familiar with)

1. Transaction management in Spring, which methods are supported, and the specific methods of each method.

2. Common Spring annotations.

Hibernate cache level.

What hibernate is and how it works.

How hibernate implements lazy loading.

6, Hibernate how the relationship between classes.

What is struts1? Workflow.

8. Struts2 Workflow

9. What is Spring?

10. Introduce IOC and AOP.

11. How SpringMVC works.

12. Mybatis workflow

Mybatis differs from Hibernate.

14. Mybatis framework parameter transfer mode.

15. Briefly describe Spring transaction management and what design patterns are used to implement it.

Iv. Database

1. What are the indexes and constraints in the database?

2, use SQL statement to achieve oracle paging query.

3, students’ performance table of the common query (Baidu can be found, common query syntax)

4, database performance optimization commonly used basic knowledge, millions of data optimization (Baidu search can be).

5, Left join,right join

6. Familiar with Redis, memcache,mongodb, etc., preferably with project experience.

How to prevent SQL injection.

8, a microblog comment function of the database design, the design of the department table and staff table, the database design of the rights management system (database design this is a key, interviewed several companies have asked, and is the key).

9. Briefly describe pessimistic locks and optimistic locks.

5. Linux Basics

1. Modify system time command, modify permission command,

Six, front-end foundation

1, how to select a checkbox in javascript and set it to invalid.

2. The input of the form form can be set to readonly and disable.

What is the difference between javascript variable scope, global and local variables?

4. List three data types.

5. Javascript common objects

6. Commonly used value assignment methods in javascript, such as radio buttons, check boxes, etc. (Baidu can, javascript common basis)

7. Basic method of jquery value assignment.

8, get the value of the radio button, get the value of the check box, get the value of the drop-down list, uncheck the value of the check box, get the value of the radio button group, text box, text field assignment.

Jquery append appendTo.

10. Four sequences of CSS box models.