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- Java Applications to extract a portion of a character string and print the extracted string. import java.io.*; class ExtractString { Public static void main(String args[]) { String s,str,substr; int extract,start,len,check; try{ BufferedReader obj = new BufferedReader(new InputStreamReader(System.in)); System.out.print("Enter String : "); System.out.flush(); str=obj.readLine(); len=str.length(); System.out.print("Enter Starting position to extract characters : "); System.out.flush(); s=obj.readLine(); start=Integer.parseInt(s); start=start-1; if(start<0 || start>len) { System.out.println("INVALID POSITION"); System.exit(1); } System.out.print("Enter how many characters you want to extract : "); System.out.flush(); s=obj.readLine(); extract=Integer.parseInt(s); check=extract+start; if(check<0 || check>len ) { System.out.println("TRYING TO EXTRACT INVALID POSITION"); System.exit(1);
substr=str.substring(start,check); System.out.println("\nEXTRACTED STRING IS "+substr); } catch(Exception e) {} } }
- Java Program to implement the concept of multiple inheritance using Interfaces. interface vehicleone{ int speed=90; public void distance(); }
interface vehicletwo{ int distance=100; public void speed(); }
class Vehicle implements vehicleone,vehicletwo{ public void distance(){ int distance=speed*100; System.out.println("distance travelled is "+distance); } public void speed(){ int speed=distance/100; } }
class MultipleInheritanceUsingInterface{ public static void main(String args[]){ System.out.println("Vehicle"); obj.distance();
} }
- Write a Java Program to implement the concept of multithreading with the use of any three multiplication tables and assign three different priorities to them.
//Program: Multiplication Table Using Thread
public class Multiplicatin_Table implements Runnable{
private int number;
public Multiplicatin_Table(int number) {
this.number=number; }
@Override public void run() { // TODO Auto-generated method stub for (int i = 1; i <= 10; i++) { System.out.printf("%s: %d * %d = %d\n", Thread.currentThread().getName(), number, i, i * number); } }
public static void main(String[] args) { // TODO Auto-generated method stub
System.out.println("I will print table of 1 to 3 "); for (int i = 1; i <= 3; i++) { Multiplicatin_Table mul = new Multiplicatin_Table(i); Thread thread = new Thread(mul); thread.start(); } }
}
- Write a Java Program to draw several shapes in the created windows.
import java.awt.; import java.awt.event.; import java.applet.; / */ public class XOR extends Applet { int chsX=100, chsY=100; public XOR() { addMouseMotionListener(new MouseMotionAdapter() { public void mouseMoved(MouseEvent me) { int x = me.getX(); int y = me.getY(); chsX = x-10; chsY = y-10; repaint(); } }); } public void paint(Graphics g) { g.drawLine(0, 0, 100, 100); g.drawLine(0, 100, 100, 0); g.setColor(Color.blue); g.drawLine(40, 25, 250, 180); g.drawLine(75, 90, 400, 400); g.setColor(Color.green); g.drawRect(10, 10, 60, 50); g.fillRect(100, 10, 60, 50); g.setColor(Color.red); g.drawRoundRect(190, 10, 60, 50, 15, 15); g.fillRoundRect(70, 90, 140, 100, 30, 40); g.setColor(Color.cyan); g.drawLine(20, 150, 400, 40);
pin = new TextField(10); Button b=new Button("My Details"); add(namep); add(name); add(Streetp); add(street);
add(Cityp); add(city); add(Pinp); add(pin); add(b); b.addActionListener(this); // register to receive action events name.addActionListener(this); pass.addActionListener(this); } // User pressed Enter. public void actionPerformed(ActionEvent ae) { n=name.getText(); name.setText(n); s=street.getText(); street.setText(s); c=city.getText(); city.setText(c); p=pin.getText(); pin.setText(p); repaint();
} public void paint(Graphics g) { g.drawString("Name: " + name.getText(), 6, 60); g.drawString("Street " + street.getText(), 6, 80); g.drawString("City: " + city.getText(), 6, 100); g.drawString("Pin: " + pin.getText(), 6, 120); } }
- Java Program to demonstrate the Multiple Selection List-box. import java.applet.Applet; import java.awt.Graphics; import java.awt.List; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; /*
*/ public class GetSelectedItemFromMultiSelectExample extends Applet implements ItemListener{
List list = null;
public void init(){
//create a multi select list list = new List(5, true);
//add items to a list list.add("One"); list.add("Two"); list.add("Three"); list.add("Four"); list.add("Five"); list.add("Six"); list.add("Seven"); //add list add(list); //add listener list.addItemListener(this); } public void paint(Graphics g){ String[] items = list.getSelectedItems(); String msg = "";
states.add(new MenuItem("Himachal Pradesh")); states.add(new MenuItem("Rajasthan")); states.add(new MenuItem("West Bengal")); states.addSeparator(); // separates from north Indian states from south Indian states.add(new MenuItem("Andhra Pradesh")); states.add(new MenuItem("Tamilnadu")); states.add(new MenuItem("Karnataka")); cities.add(new MenuItem("Delhi")); cities.add(new MenuItem("Jaipur")); cities.add(new MenuItem("Kolkata")); cities.addSeparator(); // separates north Indian cities from south Indian cities.add(new MenuItem("Hyderabad")); cities.add(new MenuItem("Chennai")); cities.add(new MenuItem("Bengaluru")); setTitle("Simple Menu Program"); // frame creation methods setSize(300, 300); setVisible(true); } public void actionPerformed(ActionEvent e) { String str = e.getActionCommand(); // know the menu item selected by the user System.out.println("You selected " + str); } public static void main(String args[]) { new SimpleMenuExample(); } }
- Java Program to create frames which respond to the mouse clicks. For each events with mouse such as mouse up, mouse down, etc., the corresponding message to be displayed.
import java.awt.; import java.awt.event.; import java.applet.; /
*/ public class Mouse extends Applet implements MouseListener,MouseMotionListener {
int X=0,Y=20; String msg="MouseEvents"; public void init() { addMouseListener(this); addMouseMotionListener(this); setBackground(Color.black); setForeground(Color.red); } public void mouseEntered(MouseEvent m) { setBackground(Color.magenta); showStatus("Mouse Entered"); repaint(); } public void mouseExited(MouseEvent m) { setBackground(Color.black); showStatus("Mouse Exited"); repaint(); } public void mousePressed(MouseEvent m) { X=10; Y=20; msg="NEC"; setBackground(Color.green); repaint(); } public void mouseReleased(MouseEvent m) { X=10; Y=20; msg="Engineering";
import java.awt.event.; public class prg11 extends Applet { int x=0,y=0,c=0; public void init() { addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent me) { c++; x=me.getX(); y=me.getY(); repaint(); } }); } public void paint(Graphics g) { if(c%4==1) g.drawOval(x,y,150,150); else if(c%4==2) g.drawRect(x,y,150,150); else if(c%4==3) g.drawOval(x,y,100,150); else if(c%4==0) g.drawRect(x,y,100,150); } } /
Mouse click
*/
12. Java program to append text to existing file. import java.io.IOException; import java.nio.file.Files; import java.nio.file.Paths; import java.nio.file.StandardOpenOption; public class AppendFile { public static void main(String[] args) { String path = System.getProperty("user.dir") + "\src\test.txt"; String text = "Added text"; try { Files.write(Paths.get(path), text.getBytes(), StandardOpenOption.APPEND); } catch (IOException e) { } } }
