entry level java interview questions

1. What is Java ee?A: Java EE is a multi-layer (Multi-diered), distributed (distributed), and component-based enterprise-level application model (enterpriese application model) proposed by Sun ). In such an application system, different components can be divided by function. These components can be located on different computers and at the corresponding

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 applicationco

encryption mode. (1) Symmetric and asymmetric, sequential: transmission encryption, data storage encryption, data integrity type identification, Key management; 3. Ask the hasshmap underlying data structure, arraylist-linklist difference and why there is such a difference; array comparison method; difference between basic type and reference data type; the difference between the interface and the abstract class; (1) HashMap is a line program that is not secure, not synchronized. HashMap allows y

The following questions will be used:4Tables. For details about the fields in these four tables, refer to the following content: Employees (employee_id number (6) Not null, first_name varchar2 (20), last_name varchar2 (25) not null, email varchar2 (25) not null, phone_number varchar2 (20 ), hire_date date not null, job_id varchar2 (10) Not null, salary number (8, 2), commission_pct number (2, 2), manager_id number (6), department_id number (4 ))

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

Controller: When the user clicks the Submit button in the Web page, the controller accepts the request and invokes the appropriate model to process the request. The corresponding view is then called according to the result of the processing to display the results of the processing. MVC process: First the controller accepts the user's request, invokes the corresponding model for business processing, and returns the data to the controller. The controller invokes the corresponding view to

(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

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 Java is the introdu

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)

simpledateformat ("HH: mm: SS") ;}// customer class, representing various customers public class customer {private string name; // customer type 2, 1, 3 sub-table representatives, fast, VIP, common customer private int type; private partition list These hundreds of lines actually caused Stack Overflow during JS coloring and parsing. IE6 is not good... I like to write a single-class single file for something I want to learn and test. This facilitates copying, pasting, and directly compiling. Th

difference between the 5.sendRedirect () and Forward () methods?The Sendredirect () method creates a new request, and the forward () method simply forwards the request to a new target. After redirection (redirect), objects that were within the scope of the previous request are invalidated because a new request is generated, and after forwarding (forwarding), objects within the scope range of the previous request can be accessed. Sendredirect () is generally considered to be slower than forward

the Connection object. You can set the isolation level of the current link by calling the settransactionisolation of the Connection object, and the field of the connection object, as with the parameter level:　　To set the isolation level part of the code in JDBC:　　　PostScript: The isolation level setting is only valid