how to learn java programming language online

1. What is socket? The so-called socket is also called "socket". It is used to describe the IP address and port and is a communication chain handle. Applications usually send requests to or respond to network requests through "Sockets. Taking J2SDK-1.3 as an example, the socket and serversocket class libraries are located in the java.net package. Serversocket is used on the server side. socket is used to establish a network connection. When the connection is successful, a socket instance is gen

Write a Java program that calculates the circumference length and area of the RADIUS 3.0 and outputs the results.Note: The system class math is in the Java.lang packet, and pi π can be obtained by the static attribute pi of the math class, which is defined as "public static final double PI = 3.14159265358979323846;".1 PackageCom.hanqi;2 3 Importjava.lang.*;4 5 //Write a Java program that calculates the cir

Recently learning swing programming, according to the teacher's teaching video learning using java.awt.*, javax.swing.*, java.awt.event.* package for a simple tank war game programming, Learning JFrame, JPanel and other containers and components of the use of Learn the various ways to draw graphics using graphics, as well as some event monitoring and processing m

() {return NewImplementation1 (); }}classImplementation2 implements Service { Public voidmethod1 () {System. out. println ("Implementation2 method1"); } Public voidmethod2 () {System. out. println ("Implementation2 method2"); }}classImplementation2factory implements Servicefactory { PublicService GetService () {return NewImplementation2 (); }} Public classFactories { Public Static voidServiceconsumer (servicefactory fact) {Service s=NewFact.getservice (); S.method1 (); S.METHOD

Use of Setactioncommand () and Getactioncommand ()/** * Function: event handling mechanism * */package Com.test3;import java.awt.borderlayout;import java.awt.color;import java.awt.Graphics; Import Java.awt.event.actionevent;import Java.awt.event.actionlistener;import Javax.swing.jbutton;import Javax.swing.jframe;import Javax.swing.JPanel; @SuppressWarnings ("Serial") public class Demo9_3 extends Jframe{mypanel P1 = new Mypanel (); JButton button1 = new JButton ("Black"); JButton button2 = new JB

) {super.paintcomponent (g); G.drawoval (GetWidth ()/2-radius, getheight ()/2-r adius,2 * radius, 2 * radius);}} Class Enlargelistener implements ActionListener {//First step: Create Enlargelistener Class Implementation ActionListener interface// Fifth step: In order for actionperformed to access the Enlarge method, define the class as Inner class@overridepublic void actionperformed (ActionEvent e) {// Fourth step: Overwrite the Actionperformed method in the interface once the operation is monit

Java.awt.flowlayout;import Java.awt.event.actionevent;import Java.awt.event.actionlistener;import javax.swing.jbutton;import javax.swing.JFrame; @SuppressWarnings ("Serial") public class Anonymouslistenerdemo extends jframe{private JButton stringnew = new JButton ("new");p rivate JButton Stringop En = new JButton ("open");p rivate JButton stringsave = new JButton ("Save");p rivate JButton stringPrint = new JButton ("Print ");p ublic Anonymouslistenerdemo () {setlayout (New FlowLayout ()); Add (

Click the text mouse drag the text will be dragged with the mousePackage Chapter16;import Java.awt.borderlayout;import Java.awt.graphics;import java.awt.event.mouseevent;import Java.awt.event.mousemotionlistener;import javax.swing.jframe;import Javax.swing.JPanel; @SuppressWarnings ("Serial ") public class Movemessagedemo extends Jframe{public Movemessagedemo () {Moveablemessagepanel p = new Moveablemessagepanel (); SetLayout (new BorderLayout ()); Add (P);} public static void Main (string[]

*/public void setnumberofyears (int numberofyears) {this.numberofyears = Numberofyears ; }/** return Loanamount */public double Getloanamount () {return loanamount; }/** Set a newloanamount */public void Setloanamount (double loanamount) {this.loanamount = Loanamount; }/** Find Monthly payment */public double getmonthlypayment () {Double monthlyinterestrate = ANNUALINTERESTRATE/1 200; Double monthlypayment = Loanamount * Monthlyinterestrate/(1-(Math.pow (1/(1 + monthlyinterestrate), numbe

size of the chessboard, followed by a number of NXN 0 or 1.Output format:One of three outputs: X O NIL are all uppercase Letters.Input sample: 4 1 0 0 1 0 1 0 0 0 0 1 0 1 0 0 1 Sample Output: X Time limit: 500ms Memory limit: 32000kbImport java.util.Scanner; public class Hello{public static void main (string[] Args) {//TODO auto-generated method Stubscanner in=new Scanner (System . in); int N=in.nextint (); Th

Suggestions for solving Java programming language thread problems (4) -- Linux general technology-Linux programming and kernel information, the following is a detailed description. Access problems The lack of good access control will make thread programming very difficult.

(NewRunnable () {@Override Public voidrun () { for(intj = 0; J ) {home.addcount (); } Try{Thread.Sleep (1000); } Catch(Exception e) {e.printstacktrace (); } System.out.println (Thread.CurrentThread ()+":"+home.count); } }); T.start (); } //sleep three seconds, wait up the top. Try{Thread.Sleep (3000); } Catch(Exception e) {e.printstacktrace (); } System.out.println ("Total:" +home.count); } Public voidAddcount () {count++; }}Mute

Step 1: fully understand Socket1. What is socket?The so-called socket is also called "socket". It is used to describe the IP address and port and is a communication chain handle. Applications usually send requests to or respond to network requests through "Sockets.Taking J2SDK-1.3 as an example, the Socket and ServerSocket class libraries are located in the java.net package. ServerSocket is used on the server side. Socket is used to establish a network connection. When the connection is successf

First, the object-oriented five basic features:1. All things are objects. treats an object as a peculiar variable, he can store the data, and can require it to perform operations on itself.2. A program is a collection of objects that they tell each other to do by sending a message.3. Each object has its own storage that is composed of other objects. in other words, you can create a new type of object by creating a package that contains an existing object.4. No object has its type. The most impor

), was born.1995, Masic. Java birthday-May 23, 1995.1996 Java launched the JDK1.0 version.In July 2004, Sun launched the java5.0 version.In 2009, Oracle acquired Sun for $7 billion.July 2011, JavaSE7 released.March 2014, JavaSE8 released.1.4 Java into 3 versionsJava EE, Enterprise Edition (formerly simplified EE)Javase, Java