java certification test questions

1. What are thread local variables? AnswerA thread local variable is a variable that is confined to the thread itself and is owned by the thread itself and is not shared among multiple threads. Java provides the ThreadLocal class to support thread-local variables, which is a way to implement thread safety. However, when using thread-local variables in a managed environment (such as a Web server), you should be particularly careful, in which case the w

Interview Questions for Java engineers [social recruitment], java engineers Http://blog.csdn.net/jackfrued/article/details/44921941 1. What are the features of object orientation?2. What are the differences between access modifiers public, private, and protected?3. Is String the most basic data type?4. Is float f = 3.4 correct?5. Is there any error in short s1 =

() method simply frees the CPU resources or causes the current thread to stop executing for a period of time, but does not release the lock. You can check this article for more information.These are the 50 popular Java multithreading and concurrency test questions. I did not share the answers to all the questions but

() method simply frees the CPU resources or causes the current thread to stop executing for a period of time, but does not release the lock. You can check this article for more information.These are the 50 popular Java multithreading and concurrency test questions. I did not share the answers to all the questions but

? Test toolsWhat is the most important performance issues in Java Web applications performance issuesWhat is the most important technologies/specifications in Java EE 6? What is the most important feature of Java EE 6?Do you like pair programming? What's your views on Agile methodology comparing to SDLC? Pair programm

115 Java Interview Questions and answers-ultimate list (I), 115 java This article will discuss various types of interview questions in Java interviews, which allow employers to test candidate's

The following is a comprehensive revision of the original Java face test set and answers to the questions and answers, the original topic has a lot of repeated topics and worthless topics, there are a lot of reference to the answer is also wrong, the revised Java side Test s

request, query the phone number of the place of the pen test (remember incomplete, not listed), how to design the algorithm? More requests, such as 5w, how to design the entire system?2, high concurrency situation, how our system supports a large number of requests3. How the cluster synchronizes session state4, the principle of load balancing5, if there is a particularly large amount of traffic, to the database, how to do optimization (db design, dbi

questions Question 1:Import java. util. ArrayList;Import java. util. List;Class Vehicle {Public void run (){System. out. println ("this is the run method of the vehicle ");}}Class Motor extends Vehicle {Public void run (){System. out. println ("this is the Motorrun method ");}}Class Ship extends Vehicle {Public void run (){System. out. println ("this is the Ship

Some days ago, I wrote an article in the blog Park, how to introduce my project experience in the interview, Harvest more than 2000 clicks, which undoubtedly inspired me to continue to share the enthusiasm, today I come to share another interview can even help everyone to reverse the skills, this article is from the Java Web Lightweight Development Interview tutorial from the excerpt.--------------------------------------------------------------------

Simple Java: Nine Frequently Asked Questions about Java Maps, simplemaps In general, Map is a data structure composed of key-value pairs. The key cannot be repeated in Map; This article summarizes the nine most common problems (about Java Map and Its Implementation classes ); For the sake of simplicity, I will not use

strongly recommend that you read the locks carefully before you go to a multithreaded interview, as it is currently heavily used to build the client cache and transaction connectivity space for the electronic trading final. 3 The difference between the wait and sleep methods in Java? Java thread interview questions that are often asked during a phone interview

Let's talk about some questions about the java programmer interview. This blog post is intended for recent graduates and java programmers who have been working for about two or three years. Why do I need to change jobs? This is a broad question. Everyone has an answer. For example: The company is not well-treated, The salary increase does not meet the expected r

Logical Thinking interview questions-java backend interview-,-java backend(-1) Preface I recently participated in an interview and was very interested in the pen questions. I will return to Baidu. Thinking about these questions reminds me of the association in modeling. I fe

⑥modelandview view is a logical view, and Dispatcherservlet also uses viewresolver to accomplish parsing from a logical view to a real view object.⑦ when a real view object is obtained, Dispatcherservlet uses the View object to render the model data.The ⑧ client gets a response, either as an ordinary HTML page or as an XML or JSON string, or as a picture or a PDF file.37. Why do you choose to use the Spring framework (what are the benefits of the spring Framework for enterprise development)?Ans

The system has organized a bit of questions about Java, including Basic, Javaweb, frame, database, multi-threaded, concurrent articles, algorithms and so on, updated in succession. Other aspects such as the front end and so on the face of the questions are also in the collation, there will be.Note: At the end of the article there are benefits! PDF version can be

First, design and planning1. The first step in planning a benchmark is to ask questions, clear the document, and then decide whether to use standard benchmarks or design specific tests.2. Even if you do not need to create a dedicated benchmark test, it is also necessary to write down the test plan in detail.3. Specifications should be established to document the

code in addition to code optimization?Generics in Java are constructed at compile time, you can understand generics by looking at the compiled class file, or you can view it to solve generic-related problems.4. Which of the following occurs at compile time, at run time, or both? method Overloading : This occurs at compile time. Method overloading is also known as compile-time polymorphism, because the compiler can choose which method to use based

In this article we are going to discuss the different types of face questions in a Java interview, which allow employers to test the candidate's Java and common object-oriented programming capabilities. The following sections are divided into two chapters, the first of which will discuss object-oriented programming and

In this article we are going to discuss the different types of face questions in a Java interview, which allow employers to test the candidate's Java and common object-oriented programming capabilities. The following sections are divided into two chapters, the first of which will discuss object-oriented programming and