oracle interview questions for java developer

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

-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

position, filling the original AI (i), the AI value inserted into the space after the shift of J * * This implementation of a card from I, inserted into the exact position. Loop through the process sequentially, and each element of the loop is eventually inserted into the position it should be in, thus sorting is achieved. * [1, 2, 4, 5, 6, 7, 9, 3, 8] * [1, 2, 3, 4, 5, 6 , 7, 9, 8] * @param array * @param up */Public static void Insertsort (Int[] Array, Boolean up) {for

(); - } - - Public BooleanIsEmpty () {///Bottom call is LinkedList's IsEmpty () method to determine if the set internal data is empty - returnlink.isempty (); in } -}(2) test of Mystack:1 Packagecn.itcast_05;2 3 /*4 * Test of Mystack5 */6 Public classMystackdemo {7 Public Static voidMain (string[] args) {8 //To create a collection object9Mystack ms =NewMystack ();Ten One //adding elements AMs.add ("Hello"); -Ms.add ("World"); -Ms.add ("

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

many occurrences in the array are greater than half @Test public void Test () {int[] num = {1,2,2,2,2,2,2,4,2,4,6,4,2,6,8,2,7,7}; SYSTEM.OUT.PRINTLN (Morethanhaft (num)); } public int morethanhaft (int[] num) {int result =-1; int times = 0, for (int i=0;iTopic Eight:Determines whether an array is the stacking order of another stack @Test public void Test () {int[] num = {1,2,3,4,5};//int[] num1={1,2,3,5,4}; int[] num2={2,1,5,3 , 4}; stackTopic Nine:Draw 5 cards from poker, 0

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

methods.A class can implement many interfaces, but only one abstract class is inheritedClasses can not implement all methods of abstract classes and interface declarations, and of course, in this case, the class must also be declared abstract.An abstract class can implement an interface without providing an interface method implementation.The variables declared in the Java interface are final by default. An abstract class can contain non-final variab

Java Questions Answers 1. What is the difference between an applet and an application? A Java application is made up of a main () method declared as public static void that accepts a string array argument, along with any other classes that main () CILS. it lives in the environment that the Host OS provides. A Java a

"Declaration" Source: Power node Java Institute, reprint Source: Script House (The answer to a small number of questions was slightly altered by me) 1, what is the thread local variable. A thread-local variable is a variable within the thread itself, owned by the thread itself, and not shared among multiple threads. Java provides a ThreadLocal class to support t

I was also reading the interview book while learning the video. The record is as follows: 1. LostAfter learning the 2010java high-tech video from Teacher Zhang Xiaoxiang for so many days, he looked at generics, reflection and other things and turned his mind away. He just learned that none of the Main Lines dragged me. That is to say, I am eager to know what major technologies will be required for future development and what is the core of

shut down after the database is connected? What is the easiest exception to throw when closing a database. (1) Paging: "SELECT * from User Limit" + (pageNo-1) *pagesize+ "," +pagesize; (2) Sum: SELECT * FROM user1 Union select * from User2; (3) Manual connection database: Connection cn=null; PreparedStatement Pst=null; Result Rs=null;try{class.forname (driverclassname); Cn=drivermanager.getconnection (Url,username,password);p st= Cn.preparestatement ("SQL");p st.setstring (1,studentname); Resul

will modify the Java.exe startup path of SQL developer. You cannot click SQL Developer to define the Java.exe path in the Start menu, because the path is already initialized, and a single click of SQL Developer will report the above error. You will need to modify the configuration file to modify the Java.exe path at this time.1. Locate the sqldeveloper.conf file

This is the topic discussed during the last interview and is recorded.Spring Why use Spring? What are the benefits of IoC? What are the benefits of scalability? How to instantiate a Bean? What is the difference between ApplicationContext and BeanFactory? How can I read external files through Spring? Can Bean IDS be repeated in the Spring configuration file? What is automatic assembly and type check in Spring? Can ApplicationContext be loaded

roles, which can be provided by different developers, each role must follow the EJB specifications provided by Sun to ensure compatibility between them. These six roles are the EJB component developer, application composite, deployer, EJB server provider, EJB container provider, and system administrator. The three objects are the remote interface, home interface, and Bean class. 5. What is the difference between EJB and

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