core java interview questions and answers for experienced

The following content is the original Java surface of the online question set and the answer after a comprehensive revision of the responsible questions and answers, the original topic has a lot of repetitive topics and worthless topics, there are many reference answers is also wrong, modified

(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

. 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 questions: Implementation of stacks and queues During the interview, stacks and queues are often checked in pairs. This article includes the following stack and queue test content: 1) stack Creation 2) create a queue 3) Two stacks implement one queue 4) two queues implement one stack 5) design the stack

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

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

client. The expression is defined between the two tags, 9. What does the implied object mean? What are the hidden objects?JSP implied objects are some Java objects in the page, and the JSP container allows these Java objects to be used by developers. Developers can use them directly without a clear statement. JSP implicit objects are also called predefined variables. The following lists the implied objects

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

in February. The first day of 1751 in England was March 25, 11 days worse than France.After the United States adopted the Gregorian calendar, it went back hundreds of years, so that the dates originally recorded could be expressed in two calendars (usually to provide two dates for more precise purposes). For example, George Washington's birthday changed from February 1731 11 to February 1732 22.When you read a volatile variable in a thread, you can eventually read the value that it updated.A f

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

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