java 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 t

Today we will be divided into four parts to talk about this problem, because I am a Java origin, so about the main language problems are related to Java, other language students can selectively ignore. In addition, the interview when the general interviewer's problems are closely linked, gradually in-depth, this point in the following can be more clearly felt.1,

= mysql_query("SELECT * FROM user WHERE country = ‘China‘"); if0) { ... } // 有效率的： $r = mysql_query("SELECT 1 FROM user WHERE country = ‘China‘ LIMIT 1"); if0) { ... } 4. Jianjian Index for search wordsRefer to Java interview Preparation 15: Database--Index 5. Use a fairly typed example in the Join table and index itIf your application has many join que

generation object will replicate multiple times in the Survivor area, which can increase the lifetime of the object's younger generations, increasing the probability that it will be recycled in the younger generation. The parameter is valid only for serial GC.-xx:pretenuresizethreshold object more than how large is directly in the old generation to allocate 0 units of bytes The Cenozoic adopt parallel scavenge GC When invalid another case is a large array object that is allocated directly in th

through the HashMap bottom to achieve, but is HashMap value is all assigned to a constant object object, internal additions and deletions and other methods are directly called HashMap method, so do not repeat, and so on, such as HashMap in-depth analysis. private transient hashmap map; private static final object PRESENT = new object ( ); public boolean add (e e) { return map.put (E, PRESENT) ==null ; public boolean remove (Object o) { return map.remove (o) ==present;

a behavior, once the behavior changes, there is no need to modify many classes, just modify this behavior. AOP is this decentralized programming approach that encapsulates "focus" in "facets"2) control reversal IOC (inversion of control) controls refers to dependencies between program-related classes. In traditional conceptual design, it is usually the caller who creates an instance of the callee, in Spring, the work of creating the callee is no longer done by the caller, but by the The Spring

In Java, exceptions are classified as checked exceptions, and run-time exceptions. Both are in the exception class hierarchy. This type of easy-to-choose quiz did you master the exception class and know which exception classes must be capturedThe following figure shows the inheritance relationship of the Java exception class.Figure 1The pink is the checked exception (checked exceptions), which must be captu

framework, you'll think of Collectoin, and you'll answer arraylist\hashmap\hashset, and you'll talk about their differences. If more in-depth, hashmap principle, For-each principle and copyonwritearraylist, arrayblockingqueue and chat to these two classes, And then we'll talk about the problem under the java.util.concurrent bag.1.Collectoin Set Frame2.arraylist\hashmap\hashset differences3.HashMap principleRefer to the following two links, as long as you understand should be no problem, simply

Class loading processAfter a class has been written and compiled into bytecode, it has seven stages to load into memory:　Load =-(verify, prepare, parse) + = Initialize = Use = UninstallThe three steps in parentheses can be consolidated into a " connect " step. The steps are not the end of a phase, but a phase begins. It's just that their starting phase basically follows this order (the parsing phase is more likely to occur at the time of use, with the purpose of dynamic binding), and these phase

exceeds the range of byte [-128,127], so dividing 257 by the range of Byte (256) takes the remainder to get b=1; it should be noted that, when a=200, the remainder of this time except 256 should be 56, not 200.A truncated (truncation) occurs when a floating-point type is assigned to an integer type. That is, the fractional part is removed, leaving only the integer part. At this point, if the integer exceeds the target type range, the range of the target type will be the remainder.The basic type

.-abstract class can have attribute, interface can only have method. -the method of an interface must not be implemented, and an abstract class can have an implementation method.-the method in the interface is default and must be public , and the abstract class can be protected. 3. Instantiate a process for a class that has not been loaded.See the book.4. Error errors and exception exception classification, throws and throw differences.Java exceptions (including exception and error) are divided

Front-end interview preparation Notes 1, interview preparation notes I. Common web security and protection principles 1. SQL Injection principles The SQL command is inserted into the web form to submit or enter the query string of the domain name or page request, and finally the server is deceived to execute malicious

filtering, such as the study of teamwork and communication skills, which should not be a problem for everyone. So in this article, we take the Java back-end advanced development as an example to tell the preparation point of the interview. The method is generic, and so can other students in other directions. ------------------------------------------------------

Interview preparation series 03 ---- Summary of Binary Tree questions in the interview, 03 ---- Binary Tree Interview preparation series 03 ---- Summary of Binary Tree questions in the interview This article is the first article i

Interview preparation series 03 ---- Summary of Binary Tree questions in the interview Interview preparation series 03 ---- Summary of Binary Tree questions in the interview This article is the first article in the

technical, it is difficult to manage the team, and not very good to do technology cost assessment. Of course, can be changed to do other things, after all, life is so long, if they do not like to do development, do not compete with bugs. 2. Long-term preparation-dry goods if you're in a position where you've decided not to do the technology, skip the rest of the section, and if you continue with the technology, this will be the dry goods for self-im

increment of the variable itself declaration, the parent class has the parent class9. ID Type10, on the foundation of the array Nsarray basic video did not see! But 10 pieces of diary want us to have its content!Check it out for yourself!Proficiency in the C Language section and OC sectionPart of the proportion of the programming is to be considered!Is the interview process expected to be answered orally?Do you want to do the

concurrency Tens large database in Hangzhou famous e-commerce website-read/write separationOptimizing the experience of high concurrency Tens large database in a famous e-commerce website in Hangzhou-SQL statement optimization optimization of a famous e-commerce website in Hangzhou high concurrency Tens large database experience-disk I/O performanceAfter reading the above article, the basic moves you have, as you say there is no recruit win, or recruit deadly, see your fortuneThe difference bet

Luck2. Talk about Dependency InjectionAll right, I admit I don't understand, the interviewer said jump right in.Please read: http://www.cnblogs.com/xingyukun/archive/2007/10/20/931331.html3. Unit Testingis not feeling very familiar, just don't know how to describe, the pain is extremelyPerhaps these two articles can help us:Http://www.cnblogs.com/hwh_/archive/2011/02/16/1956006.htmlHttp://www.cnblogs.com/Chinasf/archive/2008/03/07/1094334.htmlThree today, there is not a lot of personal opinion,