java interview questions for testers

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

(throughput) collector? The throughput collector uses a parallel version of the new generation garbage collector, which is used for medium-sized and large-scale data applications. The serial collector is sufficient for most small applications, which require about 100M of memory on modern processors. 41. In Java, when can objects be garbage collected? This object can be recycled when the object becomes inaccessible to applications that currently use t

XML interview questions include XSLT techniques for transforming XML files, xpath,xquery, and XML basics such as DTDs or schemas. This article will see 10 common XML interview questions and answers. Most of these questions are asked in a

., GC can avoid memory leaks and stack overflow, effectively improve the efficiency of memory utilization, It also frees programmers from tedious memory management.The string S=new string ("xyz"); How many stringobject are created?2, 1 in the text pool, 1 in the heap, first create 1 "XYZ" objects in the text pool, and then copy an "XYZ" object in the heap and assign it to the reference S.Ninth, Math.Round (11.5) How much? Math.Round (-11.5) how much?Math.Round (x) equals (int) Math.floor (x+o.5f

Multithreading and concurrency issues are one of 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

create threads, how to create threads better (such as inheriting the thread class or calling the Runnable interface), and then gradually ask about concurrency problems like the Java memory model encountered in the process of Java concurrent programming, JDK1.5 introduces higher-order concurrency tools, common design patterns for concurrent programming, classic multithreading issues such as producer consume

understand the process of solving the problem, and find out what the individual has done, how to do, and what has been harvested. This is the accumulation of experience. The company ultimately needs to contribute to the work of the staff, so the need for experienced people to help solve the problem, then the ability to solve problems and thinking is very important. For students who do not have much experience, such as a new graduate or an intern, then they need a good foundation and some person

Job-hopping is not frequent, but has participated in a lot of interviews (telephone interview, face to faces interview), large/small companies, Internet/traditional software company, batter (above his business, lack of actual combat experience, hang off), also face, fortunately not because of failure and discouraged, in the process of constantly check gaps, developed a practical, Trace, continuous improveme

The Java Collection framework is the foundation of the Java programming language and is an important knowledge point in the Java interview. Here, I've listed some important questions and answers about the Java collection.What is a

Links: http://ifeve.com/java-multi-threading-concurrency-interview-questions-with-answers/Original: Http://www.journaldev.com/1162/java-multi-threading-concurrency-interview-questions-with-answersMultithreading and concurrency iss

. After creating an array or an object in the heap, you can also define a special variable in the stack that is equal to the first address of the array or object in the heap memory, and this variable in the stack becomes the reference variable of the array or object. The reference variable in the stack can then be used in the program to access an array or an object in the heap, which is equivalent to a name that is an array or an object.2 0. Can i cast int to a variable of type byte?What happens

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

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

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

Original link: http://ifeve.com/java-multi-threading-concurrency-interview-questions-with-answers/Multithreading and concurrency issues are among the questions that interviewers prefer to ask in a Java technology interview. Here,

Java interview 30 Question 1: What are the differences between final, finally, and finalize.Second, can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )?Third, the difference between static nested class and inner class is that the more you say, the better (the more general the inter