Java

Today to learn the cloning of Java objects, in writing code, sometimes we write: Object 1 = Object 2, that is, Object 2 is assigned to object 1, but there is a problem, if we modify the property value of Object 2, the same property value of object 1

Many Java™ language methods, such as Thread.sleep() and Object.wait() , can be thrown InterruptedException . You cannot ignore this exception because it is a check exception (checked exception). But what should be done about it? In Java theory and

Original source: http://www.cnblogs.com/xrq730/p/4865416.htmlCode optimization Details1. Specify the final modifier of the class and method as much as possibleA class with a final modifier is not derived. In the Java Core API, there are many

In some projects a large amount of data is often required to be read from a file, such as an XML file, a TXT file, a CSV file1. Read the local XML file, you need to pay attention to the corresponding path//reads the XML file, xmlfile the path to

Original title address: https://code.google.com/codejam/contest/90101/dashboard#s=p0Title Description:problemafter years of study, scientists at Google Labs has discovered an alien language transmitted from a faraway planet. The alien language is

1: Variable Member variable-{instance variable, static variable} Local variables 2: Arrays and strings The array length is immutable and the data type must be the same String Constructor method String

The following http://news.csdn.net/news.html for the Crawler sample site analysis, F12 view page layout, the effect is as follows: analysis, the individual data to be grilled to the unit as a tag, that is, a unit tag corresponding to an object. The

Introduction to the Properties class in JavaKnowledge without it is useless, and it has to be re-learned when it is really used.The properties class inherits from Hashtable, as follows:It is mainly used to read the Java configuration file, because

Title: Given A collection of distinct numbers, return all possible permutations.Analysis: There are two ways to solve the problemmethod One:1) The first element is exchanged in turn with all elements;2) After the exchange, it can be seen as two

The This keyword has three applications: (1) This invokes the attribute in this class, that is, the member variable in the class, (2) This invokes the other methods in this class, and (3) this invokes the other constructor methods in this class, and

Discover the design pattern of learning more and more so that they learn something too little, should touch something more, go out and walk.Decoration Mode concept:Dynamically add some extra responsibilities to an object, and the decorative pattern

Socket, also known as socket, is the endpoint that connects two-way communication between two programs on the network.The process of using a socket for network communicationService side: The server program binds a socket to a specific port and waits

Definition: Using the claims mentioned in the head first design patternThe Observer pattern defines a one-to-many dependency that allows one or more observer objects to listen to a Subject object. In this way, when the state of the observer changes,

Defined:The ability to dynamically extend an object without having to change the original class file and use inheritance. It is by creating a wrapper object, that is, decorating to wrap the real object.Overview:1. The decorator and the decorated

ObjectiveIn Java and the contract has such a package, java.util.concurrent.atomic, the package is the Java part of the data type of atomic encapsulation, on the basis of the original data type, provides an atomic operation method, to ensure thread

Use of the alias interceptor and the alias interceptor In an SSH project, sometimes one Action needs to jump to another Action. There are two ways to achieve jump between actions, one is chain and the other is redirectAction. The difference between

[Java learning notes] list sub-interface: Vector (understanding), learning notes vector 1 import java. util. enumeration; 2 import java. util. vector; 3 4 public class Test4 {5 6 public static void main (String [] args) {7 Vector v = new Vector ();

Java --> implement the group chat function (C/S mode -- TCP protocol), java ---- tcp --> Java supports TCP: --> The java.net package defines two types of ServerSocket and Socket, which are used to implement two-way connection between the server and

ThreadLocal: simple understanding and threadlocal understandingIn the code of the java open-source project, you can see the ThreadLocal attribute in a class: private static ThreadLocal clientMode = new ThreadLocal<>(); I saw ThreadLocal while

Struts2 core technology introduction, struts2 Core Technology Struts2Core Technologies To use the Struts2 framework, pay attention to the following three elements: configuration file, ing file, and Action: Global attribute file struts. properties: