Java

1. PolymorphismEncapsulation is an operation to protect a property, and inheritance is to extend the functionality of a classPolymorphism is another feature of the object-oriented programming language that is derived from encapsulation and

PackageCom.jayfulmath.designpattern.command;ImportJava.util.concurrent.Semaphore;/*P (S): ① The value of the semaphore S is reduced by 1, that is, S=s-1;② if s>=0, the process continues execution; otherwise the process is set to wait state. V (S): ①

It is the true nature of the struggle to do a good deed to be held up by duty. --BalzacThe content of this lecture: 100 cases commonly used in JavaExample 1: Printing pyramidspublic class T {public static void main (string[] args) {int lay=10;for

Import Java.io.File;Import Java.io.FileInputStream;Import Java.io.FileOutputStream;Import Java.util.zip.ZipEntry;Import Java.util.zip.ZipOutputStream;public class Myzip {private static void Zip (File zipfile,file sourcefile) throws

In customizing tables and trees is the model is important, the definition is never blurredSuch as:DefaultTableModel mode = new DefaultTableModel ();JTable table = new JTable (mode);It is difficult for the next tree to correspond with the table in

The problem of passing and referencing in Java functions has always been a "scary" problem, in fact, the parameters in Java functions are passed values, the difference is that the basic data type is passed a copy of the parameter, for the class type

Inner class definition: Place the definition of a class inside another class, which is the inner class, which controls the visibility of the class, and in a way, the inner class hides the code and will not want to be hidden by externally invoked

Note:variables : In essence, a variable is actually a small area of memory (stack) that uses variable names to access the area. Therefore, each variable must be applied (declared) before it is used, and then it must be assigned before it can be used.

IntroducedTo provide concurrent processing efficiency, the user's request connection is randomly assigned to thread pool threads for processing, and HBase is also handling user requests in the same way Client code can refer to:

Never thought that the Web project can also be packaged, but there are requirements, you have to achieve, in the Internet to find a bit, found quite simple. The first is to use MyEclipse to package the Web project as shown in. Right-click on the

Chinese name, mobile number, ID number, phone and phone, Chinese, phone number:1 Public classValidateutil {2 //Chinese name Regular expression3 Public Static FinalString Name_reg = "^ ([\\u4e00-\\u9fa5]+| ( [a-za-z]+\\s?] +)$";4 5

Hadoop mapreduce custom sorting WritableComparable, hadoopmapreduce This article is published on my blog. I continued to write exercise questions today. I had a slight understanding of the partition last time. Now I want to write a sorting example

The interface cannot be instantiated. Today, when looking at the template method design mode, we found that an interface was added to the anonymous class during interface callback. I thought it was strange that I wrote a small program to test it.   /

RedisFile, my open-source project Redis is a well-known cache database with powerful functions and simple usage. The RedisFile project I designed is used to simulate uploading file data to the cache. Project in oschina, is:

Get the difference of date in java     When we want to calculate the difference value, we must think of "2014.12.14"-"2014.12.20" = 4. This method, but java does not directly give us this method, so what I want is to convert the string to the Date

[Programmer interview questions selected 100 questions] 12. traverse the binary tree from top to bottom[Question] Enter a binary tree, print each node of the tree from top to bottom, and print the tree from left to right in the same layer. For

How to read xml from dom4j in java I have learned about XML in BS, but I have always understood XML as "not important" and "Can I do anything ". But in the absence of xml, programmers must design their own transmission interfaces to transfer data

[SSO single point series] (3): add the verification code on the logon page, sso Single Point   This article mainly explains how to add the verification code function on the logon page. The default logon page only supports the username and password

Java object-oriented package & amp; import1. package) The definition of a package can be understood as a folder in which compiled class classes are integrated. Format:   The folder location of the package class;   The folder is saved

Data Structure and algorithm sorting (Summary 1)Sorting enables one of the most commonly used algorithms in our actual development to classify the internal sorting according to the principles in the sorting process, in general, it can be divided