Java

When multiple threads operate the same resource at the same time, they will encounter concurrency problems, such as bank transfer, ticketing system, etc. To avoid these problems, we can use the Synchronized keyword to solve, the following for

All positive integers between 1-100 are stored in a list collection and the objects in the collection that have an index position of 10 are removed from the collection. PackageCom.hanqi.jihe;Importjava.util.ArrayList;Importjava.util.List; Public

Java language Overview:Do not give language bondage, mainly learn to develop ideas, language is a toolIn the company's main learning is the development processJava is a compiled language:Compiled languages: Need to be compiled to runInterpreted

1. Bytecode is a computer-readable program.2. Run tool: Java.exe, compiler: Javac.exe.The 3.java platform is a pure software platform that runs on other hardware-based platforms.The 4.java platform has two components: the Java Virtual machine ( JVM),

A general generalization of something that has the same characteristics, such as (Cat and dog)Object: A specific thing in a class (eg: Xiao Ming's cat);To create a class:public class class nameDefining propertiesPublic property Type

1. Execution efficiency of String, StringBuffer, StringBuilderStringBuilder > StringBuffer > StringOf course this is relative, not necessarily in all cases such as:String a = ' a ' + ' B ' + ' C ' is more efficient than stringbuffer buffer = new

Concurrentmodificationexception Exception Handling The concurrentmodificationexception exception is when iterator iterates through the ArrayList or HashMap array, modifies the size of the array by code, and iterator (Object Ele=it.next ())

Single-Case mode:1 Public classperson{2 Public StaticPerson per//defines a static variable that is used to store the object of the current class3 PrivatePerson ()//Structuring Method Privatization4 {5 }6 Public StaticPerson getinstance

First, what is generic:The purpose of generics is to specify the type of data that a class, interface, or method can accept. Just as you specify parameters when declaring a method, we can also specify its "type parameter", which is generic, when

A generic method is similar to a generic class in that it defines a generic as a method, and the format is presumably:　　Public return type method name (generic type variable name) {...}The generic method is also divided into dynamic methods and

1, network connection(1) The user sends the request (Socket) to the server;(2) The server sends a message to the user (ServerSocket), and listens for it. Accept ();2, send and receive information(1) The customer sends the message to the server:

Ask the user to enter a number, to capture and process the user input error exception, to prompt the user Packagehomework;ImportJava.util.Scanner; Public classHomework0527 { Public Static voidMain (string[] args) {System.out.println ("Please enter a

Single-Case mode: Public classperson{ Public Staticperson per;//defines a static variable that is used to store the object of the current class PrivatePerson ()//constructs a private method{} Public StaticPerson getinstance ()//defines a

Reflection in Java is a powerful tool for creating flexible code that can be assembled at run time and linked between components in a disorderly way.Reflection allows program code to access the internal information of the class loaded into the JVM,

The so-called generic interface, similar to a generic class, is to define generics on the interface, in the following format:　　Public interface Interface name Such as:1 Interface Inter {2public void show (T t); 3 }There are two ways to

1. Dynamic bindingAssociating a method call with the same method body is called a binding.Binding is based on the type of the object at run time, called late-bound or run-time binding. In addition to the static method and final in JavaFor example,

Java has a total of four classloader, the reason is called Class loader, is the program to use a class, the class loader to load memory.These four classloader are:Bootstrap ClassLoader,Extension ClassLoader,appclassloaderand URLClassLoader, their

Improve performance with Memo mode (memoization pattern)The pattern, in other word, is to cache the results that require a lot of computation and then get it right the next time you need it. Therefore, it is sufficient to use only one map at the

have been trying to understand the underlying implementation of this particularly important keyword. (Of course now also not fully understand, if there are errors later modified this article)First of all, this keyword synchronize can be said to be a

There are two types of singleton patterns in Java: lazy mode and a hungry man modeLazy Mode Code:Class load fast, slow to get objects at run timePrivate StaticStudent Stu;//Create a private static Student class object PrivateStudent () {}//Change