basic java interview questions and answers

Typical questions and answers from Oracle 1. Explanations of differences between cold backup and hot backup and their respective advantages answer: Hot Backup is applicable to databases in archive mode when the database is still working. Cold backup refers to the backup after the database is closed, applicable to all databases. The advantage of hot backup is that the database can still be used during Backup

Settings directory. Also, back up the installation information of some software.26 steps to configure a broadband routeSet the dialing attribute, which is generally pppoe and the user name and password provided by the ISP.Set valid Intranet IP addressesWe recommend that you enable the firewall function.27. Update operating system and application software patches, anti-virus, and firewall applications on a regular and irregular basis. All of theseIt is passive. The key is to have a set of feasib

, and one resource requests resources, at this time, the resource is blocked, and the acquired resource is not put. When the process obtains the resource, it cannot be forcibly deprived before it is used up.3. Can an interface inherit the interface? Can an abstract class implement interfaces? Can an abstract class inherit an object class?A: An interface can inherit interfaces. An abstract class can implement interfaces. An abstract class can inherit object classes. However, a condition is that t

operations on the memory? A: This question is difficult to answer. It is also a big question. However, you can answer questions in this way. C # can directly operate on the memory. Although pointers are rarely used, C # can use pointers. When using pointers, you must add unsafe at the front.. net uses the garbage collection mechanism (GC) function, which replaces programmers. However, the Finalize method cannot be directly used in C, instead, the fin

procedure or function using CLR reaches a certain threshold value, the system performance will decline exponentially! This is very dangerous! There may be no problem when using only a few items. If you use them on a large scale, it will cause serious system performance problems! In fact, we can make an analogy. Oracle and other database products have long supported Java programming and provided Java pool p

JSP question 1. What built-in objects does jsp have? What are their roles?A: JSP has the following nine basic built-in components (which can correspond to the six internal components of ASP ):Request client request, which contains parameters from the GET/POST requestResponse returned from the response webpage to the clientThe pageContext page is managed here.Session-related session periodWhat is being executed by applicationservletOut is used to send

"). Append ("World"). Append ("I love You"); This time S has more than one string to splice, it is supposed to be a number of objects generated, but the JVM will be an optimization, that is, only create an object, at this time it executes faster than the stringbuffer stitching. Look at this: String s2 = "Hello"; String s3 = "World"; String S4 = "I love You"; String S1 = s2 + s3 + S4; In this case, three more objects are created, resulting in a waste of memory space.

blocked thread in Java?This is a tricky problem with threading and blocking, and it has a lot of solutions. If the thread is blocked by IO, I think there is no way to stop the thread. If the thread waits for blocking by calling (), sleep (), or join (), you can break the thread and throw it to wake up the interruptedexception. How to handle blocking methods in Java, as I wrote earlier, there is a lot of in

mode. Binder Communication mode:A, telephone base station: Binder Driveb, the communication record: ServiceManagerHere is an example of a comparative image to illustrate the above communication and telephone base station in the binder communication model of the role: a classmate to call the B classmate, first a reunion to find B classmate's phone number, and ServiceManager driver's role is equivalent to the address book, There are some similar phone numbers on both sides of the communicatio

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

Question one: What do you want the work environment to be like?Standard answer: I am not demanding on the environment, I will try to adapt to the environment.Note: This is a question of whether you are testing your job search mentality, whether you are centered on yourself or on the job.Question two: What shortcomings do you think you have?Standard answer: Say some of the small shortcomings of this position, or say that their "shortcomings" is no work experience.Note: This problem is very sinist

foundation, grasp the principle of good technology, and then to practice, so as to understand a technology, learning can not have!In addition, the interview process, to maintain self-confidence, will not be bold to say no, no good disgrace, not to say you really will not, perhaps forget, perhaps did not notice, remember the interview topic, back to their own supplementary information and related informatio

foundation, grasp the principle of good technology, and then to practice, so as to understand a technology, learning can not have!In addition, the interview process, to maintain self-confidence, will not be bold to say no, no good disgrace, not to say you really will not, perhaps forget, perhaps did not notice, remember the interview topic, back to their own supplementary information and related informatio

threadlocal, Blocking Queue, counting semaphore and concurrenthashmap are more prevalent. 15 Java Multi-threaded face questions and answers 1 Now there are T1, T2, T3 three threads, how do you ensure that T2 after T1 execution, T3 after the implementation of T2 execution? This threading problem is usually asked in the first round or during the phone

the interview-based, not the actual application-based Java threading problem.A few additional questions to add:1) What is the difference between a green thread and a local thread in Java?2) What is the difference between threads and processes?3) What is context switching in multi-threading?4) What is the difference be

must be known before an interview are repeated job interviews. Just like an invisible battle, they determine the fate of different people and different people. If you want to win in the battle, you must know yourself and know what you want to win. If you want to stand out from many competitors, you will not rely on a strong body, but on a keen mind and full preparation. Are you ready when the battle is about to begin? By studying this book, you will