java coding interview questions write code

Java interview question Summary 2 (Continuous updates), java questions 1. How to format a date Answer:Date now = new Date (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyy-MM-dd hh: mm: ss "); String formatNow = sdf. format (now ); The formatNow variable is the formatted date. 2. What are several implementation m

separately, which belongs to the salvage function operation.Interview question: Please explain the difference between ArrayList and Vector.· These two classes are subclasses of the List interface;· The Vector class is provided at JDK 1.0, and the method of operation provided is synchronous, so it is thread-safeThe Operation class;· The ArrayList class is provided at JDK 1.2, and the method provided is asynchronous, so it belongs to the non-linearProcess-safe Operation classes.If later in develo

Regular Interview Questions and answers by a ribaba Java engineer, Baba java 1. Implementation of Spring AOP and IOC Http://blog.csdn.net/tarena_lixy/article/details/7096114 Http://blog.csdn.net/kiss_vicente/article/details/6901295 Http://blog.csdn.net/it_man/article/details/4402245 2. Distributed message queue and dis

After JDK5, Java provides a more convenient security mechanism that uses lock locks for thread-locked operations and release operations without using synchronized . More clear. Example:Lock lock=new Reentrantlock ();Lock.lockCode that needs to be lockedLock.unlockWhy is lock more secure? Because synchronized may cause deadlock phenomenon, specifically about the deadlock phenomenon can refer to the operating system, there is no more to say.Summarize th

need to lay the foundation, the IDE select one to understand.2. Study the idea of Java programming"Thinking in Java" This book is the Great God highly recommended books, since the great God recommended, we might as well study it.It does not guarantee that you are out of the new ranks, but will lead you to the path of master.3. Learning: HTML, CSS, JavaScript, JQuery, BootstrapIn addition to learning

. } } 56. Problem: Give an integer variable A, write two pieces of code, the first set of a bit3 is 1, the other bit does not change, how to implement it? /** * @author sanchan * @since 1.0 */ publicclassTest{ publicstaticvoidmain(String[]args){ //给一整型变量a，写两段代码，第一个设置a的bit3 为1，其他bit不变，怎么实现呢？ inta=8; //打印二进制 System.out.println(Integer.toBinaryStr

/lib/ext/*.jar, Appclassloader is responsible for CLASSPATH the specified directories or classes in the jar . In addition to Bootstrap, the other classloader themselves are Java classes, and their parent class is ClassLoader. 16. Benefits of Layered Design　　The various functions according to the calling process is modular, the advantages of modularity is can be arbitrary combination , example: If you want to register a user, the process for the displa

article to learn more about the callable,future example.6. What is Futuretask?Futuretask is a fundamental implementation of the future, and we can use it with executors to handle asynchronous tasks. Usually we do not need to use the Futuretask class, it becomes very useful when we intend to rewrite some methods of the future interface and keep the original base implementation. We can just inherit from it and rewrite the methods we need. Read the Java

115 Java Interview Questions and answers-ultimate list (I), 115 java Object-Oriented Programming (OOP) Java is a computer programming language that supports concurrency, class-based, and object-oriented. The advantages of object-oriented software development are listed bel

take out 1 position: Product: 4 The consumer takes out from 0 position: Product: 2 producer put in 0 position: Product: 5 consumer removed from 0 Position: Product: 5 producer put in 0 position: Product: 6 consumer is removed from 0 position: Product: 6 producer put in 0 Location: Product: 7 producer puts 1 position: products £ º The producers are placed in the location of the product: 8 Position: Product Consumer removed from 1 position: Product: 9 consumer removed from 0 positions: Products:

; k ) TestFunction (k, J, i);On the basis of scenario one, this scheme puts the instantiation of the cyclic variables out of the loop, which can further reduce the number of instances of the related cyclic variables, and the scheme time-consuming situation is as follows: Variable Instantiation (number of times) Initialization (number of times) Comparison (number of times) Self-increment (number of times) I 1 1 10 1

after the real object is called.Proxy mode,The proxy class and the proxy class implement the same interfaceAn instance of a proxy class in a proxy classBehavioral patterns: Focus on communication between objectsSuch as: Responsibility chain mode, iterator mode, command modeResponsibility chain ModelSimilar interceptors, etc.Command mode:Separates callers from Callee's behaviorInterpreter mode:Each syntax is an interpreter classIterator mode:Change the collection class's view traversal and add a

invocation. traditional approaches to executing code on other machines processing ss a network have been confusing as well as tedious and error-prone to implement. the nicest way to think about this problem is that some object happens to live on another machine, and that you can send a message to the remote object and get a result as if the object lived on your local machine. this simplification is exactly what J