what is elasticsearch in java

I think maybe I'm not the only one who has this question, so put it out.here are the answers given to me by Madai and Clkrst. Thank you for two people here. 　　my question is: What does the Java interface do ? 　　1, read from the book is the Java Program interface only defines

Click to enter _ more _java thousand ask1. What is a jar?The JAR (Java Archive) is a platform-independent file format. Can contain multiple files, several Java applets and their necessary components (. class files, pictures, sounds, and so on) can be packaged in a jar file.L

《　　Here are the answers from Madai and Clkrst. my question is, what does the: java interface do? 1, read from the book is the Java Program interface only defines constants and empty methods, what

With the popularity of Java object-oriented language and the emergence of multi-layer architecture applications, application reusability has been greatly improved, and the framework is also emerging in applications, and has been widely used. So what is the framework? What ar

What is the difference between extends and implements in Java?1. In the class declaration, use the keyword extends to create a subclass of the class. A class declares its own use of one or more interfaces through the implements keyword.Extends inherits a class. After inheritance, you can use the method of the parent class or override the method of the parent clas

parent class, when the methods are invoked, they must be using the methods defined in the subclass (dynamic connection, dynamic invocation). Polymorphism is divided into compile-time polymorphism and Run-time polymorphism. In which the polymorphic is static, mainly refers to the method of overloading, it is based on the different parameters of the list of differ

Let's start with the following simple statement: String x = null; What does this line of code do? Let's first think about what is variable and value ). We usually compare a variable to a box. We can use a box to hold things. Similarly, we can use variables to change the storage value. When defining a variable, you must specify the variable type. In

Click to enter _ more _java thousand ask1. What is value passingValue delivery is the transfer of a value stored in a storage unit in memory space to another storage unit. (storage units in Java are not addresses of physical memory, but have dependencies)For example://定义了一个改变参数值的函数publicstaticvoidchangeValue(int x) {??

What is the difference between an Ear, Jar, and war file? What kind of environment they are used separately. In the file structure, the three are not different, they are in the zip or jar file compression format. But they are used for different purposes: Jar file (with the extension. Jar) contains common libraries, resources, and auxiliary files (auxiliary files)

Click to enter _ more _java thousand ask1. What is the structure of the JVM instance?In the Java Virtual Machine specification, the behavior of a virtual machine instance consists of subsystems, memory regions, data types, and directives.These components describe an abstract structure inside the JVM. The purpose of these components

Click to enter _ more _java thousand questions What is the difference between a local variable, a class variable, and an instance variable Before we talk about the difference between local variables, class variables, and instance variables, we need to look at Java variables. 1, what

1> the reflection mechanism of Java is seldom used in the normal business development process, but it is widely used in the construction of some basic framework.2> What is the Java reflection mechanismThe

Class classes are implementations that define a particular class in the Java language. The definition of a class contains the member variables, the member methods, the interfaces that the class implements, and the parent class of the class. The object of the class class is used to represent classes and interfaces in the currently running Java application. For exa

object, the object is called the Unreachable object (the surviving object, the object cannot be reclaimed). Otherwise, the unreachable object can be recycled. 2, how to clean up the new generation of garbage Garbage Cleanup Algorithm The new generation of garbage collectors often assume that most objects have a very short survival time, with only a few objects surviving longer. According to this assumption, the new generation of garbage removal algor