java interview questions multiple choice

(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

. After a class implements an interface, this class implements all the methods and attributes in the interface, and the attributes in the interface are under the default state are public static, and all methods are public by default. A class can implement multiple interfaces. 50. Simple Principle and Application of the Exception Handling Mechanism in Java.When a JAVA program violates the

for int. Java provides encapsulation classes for each original type. The primitive type encapsulation class Boolean char character byte short int integer long float double reference type and primitive type behavior are completely different, and they have different semantics. The reference type and the original type have different features and usage, they include: size and speed problems, which type of data structure this type usesStorage, which is th

I. Application of the factory model in development Interview Questions:Write a simple calculator. Code implementation: Abstract An operation class: Package COM. qianyan. calcuator; public abstract class operation {// number one private double num1; // number two private double num2; Public double getnum1 () {return num1;} public void setnum1 (double num1) {This. num1 = num1;} public double getnum2 () {return num2;} public void setnum2 (double num2)

the final method, instead of making routine method calls, such as saving breakpoints and pushing stacks, this may improve the efficiency of your program. However, when your method subject is very large, or if you call this method in multiple places, your caller Code It will expand rapidly, but may affect efficiency. Therefore, use final for method definition with caution.Final classWhen using final on a class, you need to consider it carefully. Becau

because they do not have any implementations.Code. After a class implements an interface, it must implement all the methods and attributes in the interface. The attributes in the interface are public static under the default state, and all methods are public by default. A class can implement multiple interfaces. 3. Advantages and principles of garbage collection. Two recovery mechanisms are also considered. A notable feature of

. 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

1, what is the hibernate of the concurrency mechanism. How to deal with concurrency problems. Hibernate concurrency mechanism: A, Hibernate session object is not thread-safe, for a single request, a single conversation, a single unit of work (that is, a single transaction, a single thread), it is usually used only once, and then discarded. If a session instance is allowed to be shared, those that support concurrency, such as HTTP request,session beans, will cause resource contention to occur

The dashed box represents the interface, the solid wireframe represents the entity class, The thick wireframe represents the most commonly used entity classes, the dashed arrows indicate the implementation of the interface, and the implementation arrows indicate that the class can make objects of the class that the arrows refer to. Collection: Allows only one object to be placed in each location. It includes a list of "holding a set of objects in a certain order", and a set that "only allo

First, let's talk about the differences between final, finally, and finalize.Final? Modifier (keyword) If a class is declared as final, it means that it cannot generate a new subclass and cannot be inherited as a parent class. Therefore, a class cannot be declared both abstract and final. Declare variables or methods as final to ensure that they are not changed during use. Variables declared as final must be declared with an initial value, which can only be read and cannot be modified in future

Talk about final, finally, finalize the difference final-modifier (keyword) If a class is declared final, it means that it cannot derive a new subclass and cannot be inherited as a parent class. Thus a class cannot be declared as abstract and declared final. Declaring a variable or method final can guarantee that they will not be changed in use. A variable declared as final must be given an initial value at the time of declaration, and can only be read and not modified in future references. A m

the value assigned to the variable is immutable, that is, it is a constant. If final modifies an object, it indicatesThe reference assigned to this variable is immutable,What cannot be changed is the reference saved by this variable, and it is not the object pointed to by this reference. In the second case, final has the same meaning as in the first case. ActualFor the first two cases, there is a more appropriate description of the meaning of final, that is, if a variable or method parameter is

/** How do I jump out of the current multiple nested loops in Java?* In Java, to jump out of multiple loops, you can define a label in front of the outer loop statement,* Then use the break statement with a label in the code of the inner loop body to jump out of the outer loop*/Package

Problem Description:Today suddenly want to write a small application of socket communications, respectively, using bio, NIO, AIO way to achieve, to review the previous reading about TCP/UDP communication knowledge. The jdk1.8 was re-installed on the machine where the jdk1.6 was originally installed. The result is a very painful problem: My original Java_home configuration has not changed at all, but the command line execution java-version appears to b

Would show you the tackle various tree questions using iterative inorder traversal. First one is the iterative inorder traversal using stack. Hope everyone agrees with this solution.Question:binary Tree inorder Traversal PublicListinordertraversal (TreeNode root) {ListNewArraylist(); if(Root = =NULL)returnlist; StackNewStack(); while(Root! =NULL|| !Stack.empty ()) { while(Root! =NULL) {Stack.push (root); Root=Root.left; } Root=Stack.pop ();

Class ManyThreads2 {private int j = 0;Public synchronized Void Inc () {j + +;System.out.println (Thread.CurrentThread (). GetName () + "Inc" + j); }public synchronized void Dec () {j--;System.out.println (Thread.CurrentThread (). GetName () + "Dec" + j);}}public class MyTest extends Thread {Private MANYTHREADS2 many = new ManyThreads2 ();public void Run (){many.inc ();Many.dec ();Many.inc ();Many.dec ();}public static void Main (string[] args) {TODO auto-generated Method StubMyTest MyTest = new