java interview programs for experienced

SynchronousIn 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 the meth

type, not the instance. Method (SB); You can modify this instance by means of a method, but this variable cannot be modifiedJava memory leaks as the C + + programmers understand memory leaks are defined on Wikipedia as "in computer science, memory leaks can occur if programs do not properly manage memory allocations." In object-oriented programming, this is a memory leak if an object in memory cannot be accessed in the code. "But in

variable is only visible in the method, construction method, or block of statements that declares it; local variables are static variables on the stack that are seldom used except when declared as constants; Static variables are stored in a static storage area. Static variables are created at the beginning of the program and are destroyed at the end of the program. 3,a instanceof Car. ()=. ()= . () = String site = "www.runoob.com"; int len = Site.length (); String1.concat (string2); Objects of

The following is a list of videos related to this book, which will be updated dynamicallyChapter I.1 Video 1.1 The differences between JDK and JRE and JVM, install Java Development Environment 1.1.1 2nd page2 Video 1.2 Writing the first HelloWorld program 1.1.2 2nd page3 video 1.3 Developing slightly complex programs with function calls 1.1.3 5th page4 Video 1.4Debug Program 1.1.4 5th page5 video 1.5 Input

connection is simple and stateless; The HTTPS protocol is a network protocol built by the SSL+HTTP protocol for encrypted transmission and authentication, which is more secure than the HTTP protocol. HTTP uses port 80 by default, HTTPS uses 443 port by default How HTTPS ensures the security of data transmissionHTTPS is actually in the TCP layer and the HTTP layer between the SSL/TLS to secure the upper layer, the main use of symmetric encryption, asymmetric encryption, certificates, an

multithreaded programs, multiple threads are executed concurrently to improve the efficiency of the program, and the CPU does not go idle because a thread needs to wait for resources. Multiple threads share heap memory, so creating multiple threads to perform some tasks is better than creating multiple processes. For example, Servlets is better than CGI because Servlets supports multithreading and CGI does not support it.How does the volatile keyword

As a Java programmer who is often asked in an interview, let me summarize some of the questions that I often don't ask. The difference between 1.HashMap and Hashtable Often asked. Both are classes of the map interface, which enable you to map a unique key to a specific value. HashMap class is not sorted and can have a null key and multiple null values Hashtable, you cannot have null

use R2 in addition to R1, ... So go on until you can divide it evenly. The last non-0 divisor is (A, b).Time complexity O (logn).String s = "a" + "B" + "C" + "D" + "E"; how many objects are created?1 of them. "A" is a constant and only the literal value is stored.What are the output results of the following programs?String str = "ABCDEFGH";System.out.println (str.dubstring (3,5));Answer: "DE"What's the difference between StringBuffer and StringBuilde