Gold three silver four Java pre-interview preparation.

Thank you for attending our interview:

　　The following is a summary of some pre-interview preparation and technical reference questions, hoping to help you.

First, you need to prepare a job-related self-introduction, including the following:

1. Several years of Java development experience, probably summarized under what type of project, how long the experience (such as Internet finance, Internet e-commerce, traditional backstage, etc.)

2. Select one or two recent key projects specific introduction;

What is the main position, what is the content of the work, you can simply introduce the composition of the team, you are in which role (such as architecture, core code writing, mainly to do interface development, etc...) ）

What is the technology of the project (please specific to the development environment, framework, development tools, database, etc.), if there are some more innovative techniques can be specified

What is the outcome of the project (whether on-line, user-use effect, etc.)

Personal Technical Summary/outstanding achievements (such as how do you deal with technical problems; Do you have any constructive suggestions to improve the project;

　　Second, you need to look at your resume, the technical points written in your resume (especially the proficient, familiar) and then a bit more.

Most of the time, technical interviewers will ask questions in a shallow and deep way, based on the technical points written in your resume.

　　Finally, here are some of the basic Java Technical Reference questions we give you, no answer, you need to prepare yourself oh ~ Wish the interview success, come on!

Database Related: The average score of students is more than 60, and their personal average.

The difference between value passing and reference passing;

? The difference between overloading and overriding

IOC,AOP Personal understanding of the spring framework

STRUTSSTRUTS2SPRINGMVC Framework the bottom realization and their difference;

? Hibernate Framework's first-level cache and level two cache

? What is the Java ClassLoader, the HTTP protocol

? Java's memory mechanism

? Java's data structure

? Redis Basic Data type

? The propagation mechanism of spring transactions

? The role of the bean

What design patterns have you used?

The difference between multiple cases of a single case pattern

What are the factory models, what are the factory models, and under what circumstances?

What is the reflection mechanism of Java?

? What is a dynamic proxy?

? HTTP 7-layer implementation (or what is called 3-time handshake)

? How to prevent SQL injection

? How high concurrency is handled

What is a sync lock?

What is an optimistic lock?

What is a pessimistic lock?

How SQL is optimized, how SQL is executed, and how does SQL execute?

? spring's configuration file

? How to encrypt data interactions

? Memory allocation

1. What is the mechanism for saying the data connection pool?

The Java EE server starts with a certain number of pooled connections and maintains not less than this number of pooled connections. Client programs

When a connection is required, the pool driver returns an unused pooled connection and memento it as busy. If there is currently no idle connection, the pool driver creates a new number of connections, and the number of new connections is determined by the configuration parameters. When a pooled connection call is completed, the pool driver memento the connection to idle, and other calls can use the connection.

Implementation, the returned connection is the proxy of the original connection, and the Close method of the proxy connection is not a true connection, but instead returns the connection object it proxies to the connection pool.

2. What is the difference between an interface and an abstract class?

Java provides and supports the creation of abstract classes and interfaces. Their implementations have something in common, and the difference is that:

All methods in an interface are implicitly abstract. Abstract classes can contain both abstract and non-abstract methods.

A class can implement many interfaces, but only one abstract class is inherited

Class if you want to implement an interface, it must implement all the methods that the interface declares. However, classes can not implement

All methods of the abstract class declaration, of course, in this case, the class must also be declared abstract.

An abstract class can implement an interface without providing an interface method implementation.

The variables declared in the Java interface are final by default. An abstract class can contain non-final variables.

The member functions in the Java interface are public by default. The member function of an abstract class can be private,

protected, or public.

An interface is absolutely abstract and cannot be instantiated. An abstract class can also not be instantiated, but if it packages

It can be called with the Main method.

3. What are some of the available states of the thread?

Threads can be in the following States during execution:

? Ready (Runnable): The thread is ready to run and does not necessarily start executing immediately.

? Running (Running): The code of the thread that the process is executing.

Wait (Waiting): The thread is in a blocked state, waiting for the external processing to end.

? in Sleep (sleeping): Thread is forced to sleep.

? I/O blocking (BLOCKEDONI/O): Waits for the I/O operation to complete.

? Synchronous blocking (Blockedonsynchronization): Waits for a lock to be acquired.

Death (Dead): The thread completed execution.

What is the difference between 4.HashMap and Hashtable?

HashMap and Hashtable both implement the map interface, so many features are very similar. However, they

There are different points:

? HashMap allows keys and values to be null, while Hashtable does not allow keys or values to be null.

? The Hashtable is synchronous, while HashMap is not. Therefore, the hashmap is more suitable for single-threaded environments,

? and Hashtable is suitable for multi-threaded environments.

? HashMap provides a collection of keys that can be used for iteration, so HashMap is a quick failure. Another

, Hashtable provides an enumeration of keys (enumeration).

? Generally think of Hashtable as a legacy class

5.jsp nine large built-in objects?

Application Page Request response session Exception out Config

PageContext

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Gold three silver four Java pre-interview preparation.