core java interview programs

that cannot be placed into a lifelong home garden, it triggers a full collection (MAJOR-GC), which may also involve compression in order to make enough space for large objects. JVM parameters related to garbage collection: -XMS/-XMX---The initial size of the heap/maximum size of the heap -XMN---The size of the young generation in the heap -XX:-DISABLEEXPLICITGC---let System.GC () not have any effect -xx:+printgcdetail---print GC details -xx:+printgcdatestamps---Pri

In the previous article, we gave about 35 questions, all of which are basic knowledge. Some children's shoes reflect that the questions are outdated. In fact, they are not. These are the foundation of the basics, but they are also essential, there are still some basic questions in the interview questions. We gradually give different levels of questions based on the principle of ease and difficulty. Continue with the 70 questions mentioned last time. T

success in the interview. Chapter 4 the Java symbol 49java programming language, like other programming languages, is also composed of syntax rules and semantic definitions. Syntax Rules define legal sentence structures constructed by language elements, while semantic definitions explain the meanings of these sentence patterns. We should have a deep understanding of the concepts of various knowledge points

) development has no longer use the technology.3, what is cross-platform? What is the principle? JvmThe so-called cross-platform, refers to the Java language program written, once compiled, can be run on multiple system platforms.Implementation principle: Java program is running on the system platform through the Java Virtual machine, as long as the system can in

. The class loaders include the root loader (BootStrap), the Extension loader (Extension), and the System loader (System) and user-defined class loaders (java. lang. classLoader subclass ). Since JDK 1.2, the class loading process adopts the parent delegation mechanism (PDM ). PDM better guarantees the security of the Java platform. In this mechanism, the Bootstrap provided by JVM is the root loader, and ot

Multithreading and concurrency issues are among the questions that interviewers prefer to ask in a Java technology interview. Here, the most important questions are listed from the interview point of view, but you should still have a solid grasp of the basics of Java multithreading to match the problems you encounter l

of STRUTS1 is mainly implemented by Actionform, which is similar to JavaBean, which contains several readable and writable properties for storing data and data validation. In general, an action is equipped with a actionform.Struts1 views are primarily implemented by JSPs. The data that the JSP displays can come from actionform, or it can be the data that the action holds in scope (request,session,application). Of course, using struts's own labels can be a great simplification.After using STRUTS

of STRUTS1 is mainly implemented by Actionform, which is similar to JavaBean, which contains several readable and writable properties for storing data and data validation. In general, an action is equipped with a actionform.Struts1 views are primarily implemented by JSPs. The data that the JSP displays can come from actionform, or it can be the data that the action holds in scope (request,session,application). Of course, using struts's own labels can be a great simplification.After using STRUTS

is then invoked according to the result of the processing to display the processing structure.The process of MVC: first the controller receives the user's request, invokes the corresponding model for business processing, and returns the data to the controller. The controller invokes the corresponding view to display the processing structure. and renders it to the user through a view. If you want to correspond to MVC in a project, the Jsp,controler in the view corresponding project corresponds t

Java interview Knowledge point of database interview 1. Primary key Super Key candidate key foreign key Primary key: A combination of data columns or attributes that are uniquely and fully identified in a database table for storing data objects. A data column can have only one primary key, and the value of a primary key cannot be missing, that is, it cannot be

, avoid concurrency, as for code tuning, these need to accumulate, such as refactoring, factories, etc. Database tuning I'm not quite sure of that. Index and stored procedures, specific reference: MySQL Database tuning 21 best practices, other database tuning aspects look for yourselves. 5. Talk about your understanding of distributedA: Personal understanding: Distributed is to split a system/business into multiple subsystems/sub-business to work together, this process is called distributed, t

In the process of dealing with some of the more progressive junior programmers, we summed up some of the experience to help qualified programmers as soon as possible, in general, more learning, more practice does not suffer. This article comes from an excerpt from the Java Web Lightweight Development Interview tutorial.1 which knowledge points can be postponed to understandIn the

enterprise does not like to say " no problem" people, because it attaches great importance to staff personality and innovation ability. Companies do not like the job seekers ask personal benefits and other issues, if someone asked: your company to the new employees have any training programs, I can participate in it? Or what is your company's promotion mechanism? Enterprises will NBSP; very welcome, because it reflects your enthusiasm for learning

concepts of the Java programming language. Although they look similar, we don't care about these concepts as programmers, but they are different products for specific purposes. This is a common Java interview problem, and this article explains the concepts and gives the difference between them. 1) Java Development Ki

= platform + PayrollWhen we choose employing units must be measured from these two aspects, the amount of salary is important, but the platform for our own development is also very important. 4. Keep a good attitude during the interviewour interview process will meet a variety of different styles of interviewers, I from the first interview to the last interview

understanding of others. I study the source of the process, read a few people on the source of the article written very good, as follows:The Cangjie of MaySmall WolvesZhangshixi's core Java series3. Familiar with the projectFind out the most powerful features you've developed since your work, and thoroughly understand the whole process and the things involved. The project is a must-ask link in the

class file of byte code. Javac can implicitly compile some source files that are not mentioned in the command line. The difference between JDK and JRE http://blog.csdn.net/forwayfarer/article/details/3321410 (favorite blog, for reference)http://www.cnblogs.com/myitm/archive/2011/05/03/2035942.html (favorite blog, for reference)the JRE (Java Runtime enviroment) is the Java Runtime environment. For users of

The scope of this article is not limited to the Java backend or Java Web, but some of them are examples of this, in other aspects, we can extrapolate, should also be able to get some inspiration.In the interview, we will find that some candidates are technically good, for example, in the Java Web backend, the Spring MV

process that can execute Java bytecode. The Java source file is compiled into a bytecode file that can be executed by the Java virtual machine.Java is designed to allow applications to run on arbitrary platforms without requiring programmers to rewrite or recompile each platform individually. The Java Virtual machine

carries is the core part of the software, the access and access to the question library becomes a very core class. Once these classes are decompiled, all the questions will be cracked. Now, let's consider how to protect these questions and related classes. In this example, we consider using integrated protection technology, including local code and obfuscation technology. Because the software is mainly rel