java j2ee interview questions

Multithreading and concurrency issues are one of the questions that interviewers prefer to ask in a Java technology interview. Here, the most important questions are listed from the interview point of view, but you should still have a solid grasp of

configuration. While JavaScript is interpreted to perform without generating intermediate files, "read a sentence, execute a sentence", the execution can generally be done in three ways:1. The general browser comes with the JS interpreter, which can be used directly by the browser;2. Special interpreter software can be installed node. js, executing the. js file;3. Executed with the Web page, using the Third, the data typeJava is a strongly typed language, and when it comes to data, the declarat

Analysis:Store basic data types1. Create an arr reference in the stack2. Create an int array of length 3 in the heap and initialize it, assigning the default value of 03. Point an ARR reference to an int array4. Re-assign values to each int value in an int arrayStore reference type User1. Create a Userarr reference in the stack2. Create a user array of length 3 in the heap and initialize it, assigning a default value of NULL3. Point the Userarr reference to the user array4. Create a user1,user2

understand the process of solving the problem, and find out what the individual has done, how to do, and what has been harvested. This is the accumulation of experience. The company ultimately needs to contribute to the work of the staff, so the need for experienced people to help solve the problem, then the ability to solve problems and thinking is very important. For students who do not have much experience, such as a new graduate or an intern, then they need a good foundation and some person

Job-hopping is not frequent, but has participated in a lot of interviews (telephone interview, face to faces interview), large/small companies, Internet/traditional software company, batter (above his business, lack of actual combat experience, hang off), also face, fortunately not because of failure and discouraged, in the process of constantly check gaps, developed a practical, Trace, continuous improveme

Java Architects interview questions, how to become architectsOften interview some candidates, sorted out my interview using the topic, LU continued to organize a lot of problems, so each time to draw a part to ask. The answer will be gradually released in later articles. B

The Java Collection framework is the foundation of the Java programming language and is an important knowledge point in the Java interview. Here, I've listed some important questions and answers about the Java collection.What is a

Java multi-thread interview questions 1. What is the difference between ArrayList and Vecoter? Similarities and differences between Array and ArrayListI. Differences between Array and ArrayList#1. variables of the Array type must be instantiated at the same time (at least the size of the Array must be initialized), while ArrayList can only be declared first.For e

. After creating an array or an object in the heap, you can also define a special variable in the stack that is equal to the first address of the array or object in the heap memory, and this variable in the stack becomes the reference variable of the array or object. The reference variable in the stack can then be used in the program to access an array or an object in the heap, which is equivalent to a name that is an array or an object.2 0. Can i cast int to a variable of type byte?What happens

Java programmer interview questions (86-115) 86. In Struts 2, how does Action obtain the data that the user inputs from the page, and how does it transmit its own data to the view? A: There are three ways for Action to retrieve data from the page: 1) accept parameters through the Action attribute 2) obtain parameters through the domain model 3) ModelDriven )

Java multithreading interview questions Induction1. What are the implementation methods for multithreading? The following example shows the thread synchronization. (1) Java multithreading has two implementation methods: Inheriting the Thread class and implementing the Runnable interface. Thread implements the Runnable

ImportNew Note: This article is one of the Java interview series compiled by ImportNew. You can view all the Java interview series from here. The common Interview Questions introduced in this article are about the overloading meth

picture suffix 2, how to suffix is tampered with, then each file has a magic digital file upload-magic number5, the principle and implementation of Message Queuing Answer: 1, Message Queuing Principle 2, comprehensible message queue ActiveMQVi. Database Aspects1. The MySQL query field area is not case-sensitive?Answer: Do not differentiate, even if the value is not differentiated (I asked at the time, the area of the application of the size of the meaning of what, the interviewer did not say)2,

;. java.util Package: Java Utility Class Library Java.util package. In this package, Java provides some useful methods and data structures. For example, Java provides a date (Data) class, a calendar class to produce and get dates and times, a random number class that produces random numbers of various types, and a stack (stack), vector, bit set (Bitset), and a ha

. } } 56. Problem: Give an integer variable A, write two pieces of code, the first set of a bit3 is 1, the other bit does not change, how to implement it? /** * @author sanchan * @since 1.0 */ publicclassTest{ publicstaticvoidmain(String[]args){ //给一整型变量a，写两段代码，第一个设置a的bit3 为1，其他bit不变，怎么实现呢？ inta=8; //打印二进制 System.out.println(Integer.toBinaryString(a));//输出 1000 System.out.println(Integer.toBinaryString(a|4));//输出 1100 }

). In the process of populating the handler, depending on your configuration, Spring will do some extra work for you: Httpmessageconveter: Converts the request message (such as Json, XML, and so on) to an object, converting the object to the specified response information. Data Transformation: Data conversion for a request message. such as string conversion to Integer, double, and so on. Data is initialized: Data is formatted for the request message. such as converting a string into a formatt

Collector deletes an object. 13. Can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )? An anonymous internal class is an internal class without a name. It cannot be extends (inherited) other classes, but an internal class can be used as an interface and implemented by another internal class. 14. The difference between static nested class and inner class is that the more you say, the better (the more general

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