A simple TCP Socket calculator

A simple TCP Socket calculator


//Server Class

public class SimpleServer {
public static void main(String args[]) throws IOException {
// Register service on port 1254
ServerSocket s = new ServerSocket(1251);
Socket s1=s.accept(); // Wait and accept a connection
// Get a communication stream associated with the socket

InputStream s1In = s1.getInputStream();
DataInputStream dis = new DataInputStream(s1In);
int num1 = (dis.readInt());
int num2 = (dis.readInt());
String operation = (dis.readUTF());
int ans = 0;
if (operation.equals(“add”) == true){
ans = num1 + num2;
else if (operation.equals(“sub”)){
ans = num1 – num2;
// Close the connection, but not the server socket


//Client Class

public class SimpleClient {
public static void main(String args[]) throws IOException {
// Open your connection to a server, at port 1254
Socket s1 = new Socket(“localhost”,1251);
// Get an input file handle from the socket and read the input
Scanner scanln = new Scanner(System.in);

//System.out.println(“Enter number1: “);
//int num1 = scanln.nextInt();

//System.out.println(“Enter number2: “);
//int num2 = scanln.nextInt();

System.out.println(“Search Movie: “);
String searchmovie = scanln.next();

OutputStream s1out = s1.getOutputStream();
DataOutputStream dos = new DataOutputStream (s1out);
//dos.writeInt(num1); //send to server6
//dos.writeInt(num2); //send to server6
//dos.writeInt(operation); //send to server6

//GUI.HomeMenu.homeMenu=new GUI.HomeMenu();
InputStream s1In = s1.getInputStream();
DataInputStream dis = new DataInputStream(s1In);
String st = new String (dis.readUTF());

System.out.println(“” + st);
// When done, just close the connection and exit

postgresql “New Server Registration” connection problem on ubuntu?

“connection error” or “authentication problem” when trying to register a new server in pgAdmin III?

(ubuntu or xubuntu)

This post shows how to obtain & setup the “Host”, “Port”, “Username”, and “Password” of postgresql.

1) Obtain default port.  To do that, open up /etc/postgresql/x.xversion/main/postgresql.conf

See “port= 5432”. You may change the port used by postgresql.


2) Obtain Host.

Search the listen_addresses. For instance, here 'localhost' is my defaut host. You may alter the host here.

3) Change password.

Open terminal.


~$: psql -d postgres -U postgres

psql (9.1.3) Type "help" for help.
postgres=# alter user postgres with password 'mynewpassword'; ALTER ROLE
postgres=# q
~$:sudo /etc/init.d/postgresql restart
Now you can run pgAdminIII. On form New Server Registration, set ‘Username’ to “postgres”, type in password you entered before, and the field ‘Name’ is up to your choice.

Paint & using Mouse in Java

/** this simple program allows user to draw by click & drag with the mouse. The example contains “Main.java” and “draw.java” classes. The “select paint” method in “draw.java” can be used to add new paint style, e.g, different colors. Any queries, feel free to ask…

By Devansh Ramen


// Main.java

import java.awt.Component;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
public class Main {

public static void main(String[] args) {
JFrame window = new JFrame(“Clipping”);
draw content = new draw();



import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.JPanel;
//MouseListener: interface containing methods required to ‘listen’ to mouse events
public class draw extends JPanel implements MouseListener, MouseMotionListener {

private int prevX, prevY;
private Graphics paint;
private Polygon triangle= new Polygon();
private String drawtype;

public draw() {

private void selectpaint() {
paint = getGraphics();
drawtype = “line”;
// to choose polygon to draw

public void mousePressed(MouseEvent evt) {
int x = evt.getX(); // capture start position
int y = evt.getY();
prevX = x; //set previous same position at first
prevY = y;

public void mouseReleased(MouseEvent evt) {
paint = null;

public void line(MouseEvent evt){
int x = evt.getX(); // capture new x coordinate
int y = evt.getY(); // capture new y coordinate
paint.drawLine(prevX, prevY, x, y);
prevX = x;
prevY = y;

public void mouseDragged(MouseEvent evt) {
if (drawtype== “line”){


public void mouseMoved(MouseEvent evt) { } //mouse moves but no button pressed
public void mouseEntered(MouseEvent evt) { }
public void mouseExited(MouseEvent evt) { }
public void mouseClicked(MouseEvent evt) { }


php “XSLTProcessor::setParameter” function

$xml= new DOMDocument();
$xml-> load(“testparam.xml”);

$xsl= new DOMDocument();
$xsl-> load(“testparam.xsl”);

$xsltproc= new XSLTProcessor();
$xsltproc-> importStylesheet($xsl);

$variable= “myvalue”;    //this part for passing parameter ‘myparam’ to xsl
$xsltproc->setParameter(”, ‘myparam’, $variable);

echo $xsltproc->transformToXML($xml);



<?xml version=”1.0″?>
<xsl:stylesheet version=”1.0″ xmlns:xsl=”http://www.w3.org/1999/XSL/Transform”&gt;
<xsl:template match=”/”>
–<p style=”color:red;”> Value parameter: <xsl:value-of select=”$myparam”/></p>
–<h2>Parameter works everywhere</h2>
–<table border=”1″>

—–<xsl:for-each select=”mytestnode”>

———–<td> <xsl:value-of select=”$myparam”/> </td>