java sample programs for interview

programs.Use assert In addition, assert Note that the-source 1.4 parameter must be added during compilation; otherwise, an error is returned.] Add the-ea parameter during running; otherwise, the assert row is ignored. Eighth, what is GC? Why does GC exist? GC is the meaning of garbage Collection (Gabage Collection). Memory Processing is a place where programmers are prone to problems. Forgetting or wrong memory Collection can lead to instability or even crash of

Newcachedthreadpool creates multithreading.NewscheduledthreadpoolThis thread pool can specify a fixed number of threads to be executed periodically. For example, by scheduleatfixedrate or Schedulewithfixeddelay to specify the cycle time.PS: In addition to write timed tasks (if not Quartz framework), it is best to use this thread pool to do, because it can ensure that there is always a live thread.Recommended way to use ThreadpoolexecutorIn the case of Ali's

Java Multithreaded interview questions 1. What is the difference between processes and threads? A process is a stand-alone (self contained) operating environment that can be viewed as a program or an application. A thread is a task that is performed in a process. The Java Runtime environment is a single process that contains different classes and

Java classes when Java class files are loaded by a Java virtual machine. The program runtime information collector. Collects dynamic information about the program, such as memory access, thread synchronization, creation and completion. An efficient run-time analysis engine. The collected run-time information is analyzed online, and if a potential parallel erro

Question: What happens if the main method is declared private?Answer: Can compile normally, but will prompt "Main method is not public" when run.Question: What is the difference between a reference and a pass in Java?Answer: A pass-through refers to an address rather than the value itself, and a pass value is a copy of the passed value.Question: What else to consider if you want to override the Equals method of an object?Answer: Hashcode.Question: How

Java programmer interview book-I ++, java book-IWhat are the output results of the following programs? public class program2 { static { int x = 5; } static int x,y; public static void main(String[] args) { x--; myMethod(); System.out.println(x + y++ + x); } private static v

Java Multithreading interview question 1. What is the difference between a process and a thread?A process is a standalone (self contained) operating environment that can be viewed as a program or an application. A thread is a task that executes in a process. The Java Runtime environment is a single process that contains different classes and

Elliotte Rusty Harold This article is translated from the o'reilly American Head Office website, Do not think that Java can only be used to design dynamic images on Web pages. In fact, Java is a fully functional programming language and the first choice of many programmers today. Because the Java language has a clear architecture, provides dynamic memory manageme

databaseHibernate's first-level cache is provided by the session, so it only exists in the session's lifetime, when the program calls save (), update (), Saveorupdate (), and calls the query interface List,filter, Iterate, if there are no corresponding objects in the session cache, hibernate will add the object to the first level cache and the cache will disappear when the session is closed.Hibernate's first-level cache is built into the session, cannot be uninstalled, and can not be configured

class, which usually causes them to stop executing and to wait for a lock on the object.136, what is a thread pool? Why use it? Creating threads takes expensive resources and time, and if the task is to create a thread, the response time is longer and the number of threads a process can create is limited.To avoid these problems, when the program starts, it creates several threads that respond to processing, called the thread pool, which is called a worker thread.Starting with JDK1.5, the

dispatch and dispatch, and a smaller unit that can run independently than a process. Thread's StrokeThe sub-scale is less than the process, which makes the multi-threaded procedure highly concurrency, and the process typically has independent memory units at execution time, while the threads can share memory. Programming with multithreading often leads to better performance and user experience,But multithreaded programs are unfriendly to other

time priority allocation. Url_hash assigns requests by accessing the URL results so that each URL is positioned to the same back-end server. WebService: is a cross-programming language and remote call technology across the operating system, that is, the server is written in Java, the client program can be written in other programming languages, and the client and server programs can be run on

Presumably, Java users have used JDK containers, List, Set, and Map. Every day, the code runs in thousands of JVMs around the world, and every day programmers are using these classes. Do you know who wrote these cool code? Is Joshua Bloch. He used to work in Sun. Now he jumped to Google and Google is invincible. He is a master. Although he is a master, he is also writing code, so such a person's article must be down-to-earth. Instead, some of them onl

simple way. There is only minimal data flow, and there is no case where two threads access the same object. However, in most useful programs, there is usually a flow of information between threads. Try to consider a financial application that has an account object, as shown in the following example:A number of activities in a bankpublic class Account { String holdername; float amount; Public account (String name, float amt) { holderna

classmate got up to go to the toilet.First ClassObjective: To bring into the initial object-oriented programming thinking from C language programming thinking. The main point is to understand the basic features of object-oriented programs, and its beauty.Start with a 30-minute introduction to the course objectives and an overview of the Java language, which is why this course is available, and the ability

Describes the 7 zones in the JVM, and then describes the scenarios in which each zone can cause a memory overflowProgram Counter: As the current thread doesbyte code line number indicator。 is a threadPrivateMemory, and the only piece does not report outofmemoryerror exceptions.Java Virtual machine stack: Used to describe a Java method.Memory Model: When each method is executed, it will create aStack FrameFor storinglocal variable table, operand stack,

1. What is the difference between a process and a thread? A process is a standalone (self contained) operating environment that can be viewed as a program or an application. A thread is a task that executes in a process. The Java Runtime environment is a single process that contains different classes and programs. Threads can be called lightweight processes. Threads require fewer resources to create and res

Synchronous In multithreaded programs, synchronization modifiers are used to control access to critical section code. One way is to use the Synchronized keyword to ensure thread safety for your code. In Java, synchronized-modified code blocks or methods are not accessed concurrently by multiple threads. It forces the thread to obtain a lock before entering a method, releasing the lock when it leaves

In Java programs, it is sometimes possible to postpone some expensive object initialization operations and initialize them only when they are used. At this point, the programmer may adopt deferred initialization. However, there are some techniques to properly implement thread-safe delay initialization, otherwise it is easy to have problems. For example, the following is a

JAVA multi-thread and concurrent basic Interview Q Multithreading and concurrency are one of the questions that the interviewer prefers to ask during the Java technical interview. Here, most important questions are listed from the interview perspective, but you should stil