java interview questions for 7 years experience

Java Algorithm interview questions: Write a Singleton, javasingleton Package com. swift; public class Singleton {public static void main (String [] args) {/** write a Singleton */ORC_Hungry.getOrc (). fun (); ORC_Lazy.getOrc (). fun () ;}} class ORC_Hungry {// hungry Chinese private static ORC_Hungry orc = new ORC_Hungry (); private ORC_Hungry () {} public stati

longer executed.(2) But in the case of a hash collision, the first two conditions are established, and then the last equals must be used to determine the equality of the objects.A 3.hash collision scene?(1) Generally appears in large data situations(2) The generation method of Hashcode is weak (such as the artificial production hashcode above)Summary: This chapter mainly through the introduction of hash collision once again in-depth understanding of hashmap work principle.This chapter is here,

1. The difference between String and StringBufferThe Java platform provides two classes: string and StringBuffer, which can store and manipulate strings, That is, character data that contains more than one character. This string class provides values that cannot be changed strings and the strings provided by this StringBuffer class are modified when you know that character data is going to change, you can use StringBuffer typically, You can use Stri

Difference between Forward and Redirect in common JAVA interview questions, forwardredirect The user sends an HTTP request to the server, which may be returned to the user after being processed by multiple information resources. Each information resource uses the request forwarding mechanism to forward requests to each other, however, the user does not feel reque

1. What is acitsag startup mode? For such a question, I will write an example myself. I will observe it to understand it. Activty supports four startup modes. Launchmode: Standard: each time a new activity window is started (New Operation) Singletop: if it is a target activity at the top of the stack, It will be opened directly. Otherwise, a new activity window (new) will be opened ). Singletask and singleinstance are basically the same. The difference is that if the root activity is set to sing

One: The difference between Eclipse and MyEclipseA: 1 common: Both are used to develop Java projects, and software usage is almost identical2 MyEclipse is a fee-free software, which can develop both Java and Web projects, Eclipse can only develop Java projects, if you want to develop a Web project, but also need to add additional Eclipse Web plug-in (of course, c

default branch, which must be the last branch of a switch statement. (3) default is executed when no case statement is equal to the value of the variable. The default branch does not require a break statement.Break is used to interrupt the loop statement, and continue is used to continue the loop. Breake break out of the loop body, continue continue the next loop, but the statement after continue is not running. Continue can only be used in loop statements, and break may be used in other branch

-threaded access to shared resources, due to improper access, usually a thread locked a resource A, but also want to lock resource B, and in another thread, the lock resource B, but also to lock resource A to complete its own operations, two threads want the other's resources, Instead of releasing their own resources, two of threads are waiting for a situation that cannot be performed.Java Network Programming approximate process:UDP programmingSend side:1, create the Socket object constructor Da

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 work in

rewrite the aof file, the performance impact of this persistence is minimal, but the aof file will continue to grow, aof file over the General Assembly to affect the recovery speed of master restart. Master should not do any persistent work, including memory snapshots and aof log files, in particular, do not enable memory snapshots to persist, if the data is more critical, a slave open aof backup data, the policy is synchronized once per second. Master calls bgrewriteaof rewrite aof file, a

short S1 = 1; S1 + = 1; since + = is a Java-language-defined operator, the Java compiler will treat it specially, so it compiles correctly.6. Can I store a Chinese character in char type?　　char-type variables are used to store Unicode encoded characters, and the Unicode encoding character set contains Chinese characters, so the char type can of course store Chinese characters. However, if a particular Chin

Today, I found the java interview programming questions in the Forum and thought about it. I found that I forgot my original programming basics. Question: How many equals 2x8 in the most efficient way? Along with the targeted thinking, I thought of 2x8. Later I thought that this efficiency was definitely not the best. think of the concept of a computer system,

1. String S1 = ' 123 ';String s2 = new string ();2. The difference between two ways of implementing multithreadingInheriting the thread and implementing the Runnable interface3. Single-column design mode What's the difference between lazy and a hungry man? * * *Lazy style Features: lazy loading. Delayed loading in multi-threaded security problems, through the addition of synchronization to solve, plus synchronization efficiency is low, with a double-judge method to solve the low efficiency. The

You can only manipulate a type to invert without a generic typeThe code is as follows: Packagecom.swift.fanxing;Importorg.junit.Test; Public classRenyireverse {@Test Public voidTest () {intarr[]=New int[] {1,10,6,9,2}; Reverse (arr); } Public voidReverseint[] arr) { for(inti=0;i) { inttemp=Arr[i]; Arr[i]=arr[arr.length-1-i]; Arr[arr.length-1-i]=temp; } for(intX:arr) {System.out.println (x); } }}Generic functionality can

(intx = 0; x ) { - //Invoke function - intnum =getrandom (start, end); - //Output Results - System.out.println (num); in } - } to + /* - * Write a function two explicit: return value type: int argument list: int Start,int end the */ * Public Static intGetrandom (intStartintend) { $ //think back to the random numbers we talked about between 1-100.Panax Notoginseng //int number = (int) (Math.random () * +) + 1;//(int) (Math.r

, when he asked me that HTTP, I only said 404 status code, but he was called out by the boss, and then the other came back to say the company to have experience, and then mean to hang up ...Well, if he is judging by my answer, then I will not say anything, the service ... I just wanted to say how you came up with this judgment, but I didn't ask about my project experience.But I do not want to go to this company, forget, is also their own

. 64. What are the similarities and differences between JSP and Servlet, and what are their relationships? JSP is an extension of Servlet technology. It is essentially a simple Servlet method, with more emphasis on the external expression of the application. After JSP compilation, it is "servlet-like ". The main difference between Servlet and JSP is that the application logic of Servlet is in the Java file and is completely separated from the HTML in

,finally in Try Catch finally,try?Excption and error packet structure. Oom What situation you have encountered, SOF what you have encountered.Three features and meanings of Java-oriented objects.The meaning of override and overload to distinguish.The difference between interface and the abstract class.The difference between static class and non static class.The implementation principle of Java polymorphism.

First of all, Ali's interviewers are very nice, each end of the phone will say thank you, asked you will not be a problem, will make you do not worry, will give you tips, interview experience is very good. The first time, 10 o'clock in the morning the phone to the bathroom, did not receive, a little side. 3 o'clock in the afternoon, Ali telephone side, should be a technology brother, chatting with me a lot

separately? An example is described.For:Assume that data is shared between threads. For example, the data being written may be read by another thread. Or the data being read may have been written by another thread, then this data is shared data. Synchronous access is required.When an application invokes a method on an object that takes a very long time to run, and does not want the program to wait for the method to return. Asynchronous programming should be used, and in very many cases the asyn