Playing with virtual magnets on a virtual whiteboard

public class JavaFXAssessDecideDo extends Application {
   
    @Override
    public void start(Stage primaryStage) {
       
        Circle magnet = createCircle(50,50,Color.RED);
       
        StackPane root = new StackPane();
        root.getChildren().add(magnet);
       
        Scene scene = new Scene(root, 300, 250);
       
        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
       
}
   
    private Circle createCircle(double x, double y, Color color) {
    final Circle c = new Circle(x, y, 25);
    c.setFill(color);

    c.setOnMouseDragged(new EventHandler() {

        @Override
        public void handle(MouseEvent event) {
            c.relocate(event.getSceneX() - c.getRadius(), event.getSceneY() - c.getRadius());
        }
    });

    return c;
}

References

http://stackoverflow.com/questions/10530829/javafx-drag-and-drop-moving-icon

My First JavaFX Radial Gauge

public class MyFirstRadialGauge extends Application {

    @Override
    public void start(Stage primaryStage) {
//primaryStage.initStyle(StageStyle.TRANSPARENT);
Marker temperature = new Marker(50, Color.MAGENTA);
Marker[] markerList = new Marker[]{temperature};

Gauge radial = GaugeBuilder.create()
                           .prefWidth(500)
                           .prefHeight(500)
                           .gaugeType(GaugeBuilder.GaugeType.RADIAL)
                           .frameDesign(Gauge.FrameDesign.STEEL)
                             
...
                           .title("Temperature")
                           .unit("°C")
                           .build();
       
        StackPane root = new StackPane();
        root.getChildren().add(radial);
        radial.setLcdValue(10.00);
        radial.setLcdDecimals(2);
        radial.setLcdUnitVisible(false);    
       
        temperature.setValue(30);
       
        Scene scene = new Scene(root, 500, 500);
       
        primaryStage.setTitle("My First Radial Gauge");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

References

http://harmoniccode.blogspot.ro/2012/06/jfxtras-series-radial-gauge.html 

http://grepcode.com/snapshot/repo1.maven.org/maven2/org.jfxtras/jfxtras-labs/2.2-r5/ 

Programming a JavaFX Web Service Client using NetBeans IDE 7.3

1. File -> New Project -> JavaFX -> JavaFX Application
    Project Name: JavaFXWebClient
    Finish

2. Right click JavaFXWebClient in Projects window  and select New -> Web Service Client
   (You need to have Java EE plugin installed. This is available in Tools -> Plugins.)
   WSDL URL: http://www.webservicex.net/stockquote.asmx?WSDL

3. Right click in source editor window -> Insert  Code -> Call Web Service Operation
    This automatically adds method definitions corresponding to Web service calls, for example the following piece of code:

private static String getQuote(java.lang.String symbol) {
        net.webservicex.StockQuote service = new net.webservicex.StockQuote();
        net.webservicex.StockQuoteSoap port = service.getStockQuoteSoap();
        return port.getQuote(symbol);
    }

4. Write your JavaFX Web service client using the methods defined in the previous step.

public class JavaFXWebClient extends Application {
   
    Label quoteLbl = new Label();
    TextField textFld = new TextField();
    Button btn = new Button();
   
    @Override
    public void start(Stage primaryStage) {
        btn.setText("Get IBM Quote");
        btn.setOnAction(new EventHandler() {
            @Override
            public void handle(ActionEvent event) {
                quoteLbl.setText(getQuote("IBM"));
                textFld.setText(getQuote("IBM"));
            }
        });
       
        Group root = new Group();
        root.getChildren().add(0,btn);
        root.getChildren().add(1,quoteLbl);
        root.getChildren().add(2,textFld);
       
        root.getChildren().get(0).setLayoutX(50);              
        root.getChildren().get(0).setLayoutY(70);      
        root.getChildren().get(1).setLayoutX(50);      
        root.getChildren().get(1).setLayoutY(10);
        root.getChildren().get(2).setLayoutX(50);      
        root.getChildren().get(2).setLayoutY(40);
       
        Scene scene = new Scene(root, 700, 250);
       
        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

References

http://lehelsipos.blogspot.ro/2012/09/javafx-22-webservice-example.html

http://www.actionscript.org/forums/showthread.php3?t=70742

https://netbeans.org/kb/docs/websvc/jax-ws.html

https://netbeans.org/kb/docs/websvc/intro-ws.html

SSTF (Shortest Seek Time First) Disk Scheduling Algorithm with Java

class SSTF implements DiskScheduler{
    int[] queue;
    int initialCylinder;
   
public SSTF(int[] queue, int initialCylinder){
        this.queue = queue;
        this.initialCylinder = initialCylinder;
    }

    public int serviceRequests(){
        int headMovement = 0;
        int prev = initialCylinder;
        int [] rpath = path();
        for (int i=0; i < rpath.length; i++) {
            headMovement += Math.abs(rpath[i]-prev);
            prev = rpath[i];
        }
        return headMovement;
    }
   
    public int[] path(){
       int [] resultPath = new int[queue.length];
       int now = initialCylinder;
       int [] requests = new int[queue.length];
       for (int i = 0; i < queue.length; i++){
        requests[i] = queue[i];
    }
       for (int i = 0; i < resultPath.length; i++){
        int closest = closest(now, requests);
        resultPath[i] = closest;
        now = closest;
    }
       return resultPath;
    }
   
    int closest(int k, int[] requests){
        int min = 5000000;
        int minPos = -1;
        for (int i = 0; i < requests.length; i++){
            if (requests[i] == -1) continue;
            else if  (Math.abs(k-queue[i]) < min) {
                minPos = i;
                min = Math.abs(k-queue[i++]);           
            }
        }
        int nearestCylinder = requests[minPos];
        requests[minPos] = -1;
        return nearestCylinder;
    }
   
    public void println(){
    System.out.println("SSTF head movement = " + serviceRequests());
       
        System.out.print("SSTF Path = ");
        for(int i: path()){
            System.out.print(i + " "); 
        }
        System.out.println("");
}
}

Bibliography

Avi Silberschatz, Peter Baer Galvin, Greg Gagne: Operating System Concepts with Java

Disk Scheduling Simulator with JavaFX

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Path;
import javafx.stage.Stage;

/**
 *
 * @author Cristina
 */
public class JavaFXApplication1 extends Application {
   
    @Override
    public void start(Stage primaryStage) {
      primaryStage.setTitle("Disk Scheduling Simulator");
      Group root = new Group();
      Scene scene = new Scene(root, 750, 500);
     
      int[] queue = {98, 183, 37, 122, 14, 124, 65, 67};
      int headStart = 53; 
       
      DiskScheduler fcfs = new FCFS(queue, headStart);
     
      int [] result = fcfs.path();
    
      Path path = new Path(); 
   
      MoveTo moveTo = new MoveTo();
      moveTo.setX(headStart);
      moveTo.setY(50);
      path.getElements().add(moveTo); 
     
  for(int i = 0; i < result.length; i++){      
          LineTo lineTo = new LineTo();
          lineTo.setX(4*result[i]);
          lineTo.setY(50 + i*50); 
          path.getElements().add(lineTo);
      }
     
      path.setStrokeWidth(3);
      path.setStroke(Color.BLUE);
      root.getChildren().add(path);  
      primaryStage.setScene(scene);
      primaryStage.show();
    }

Bibliography

[1] http://java-buddy.blogspot.ro/2012/02/javafx-20-exercise-draw-basic-line.html
[2] Avi Silberschatz, Peter Baer Galvin, Greg Gagne: Operating System Concepts with Java

FCFS Disk Scheduling Algorithm with Java

package javaos12;

/**
 *
 * @author Cristina
 */
public class JavaOS12 {

    public static void main(String[] args) {
   
        int[] queue = {98, 183, 37, 122, 14, 124, 65, 67};
        int headStart = 53; 
       
        DiskScheduler fcfs = new FCFS(queue, headStart);
       
        System.out.println("Head starts at: " + headStart);
        System.out.print("Queue = ");
        for(int i: queue){
            System.out.print(i + " ");
        }
        System.out.println("");
       
        fcfs.println();
       
    }
}

interface DiskScheduler
{
    public int serviceRequests();
    public int[] path();
    public void println();
}


class FCFS implements DiskScheduler{
    int[] queue;
    int initialCylinder;
    public FCFS(int[] queue, int initialCylinder){
        this.queue = queue;
        this.initialCylinder = initialCylinder;
    }
    public int serviceRequests(){
        int headMovement = 0;
        int prev = initialCylinder;
        int [] rpath = path();
        System.out.println(rpath.length);
        for (int i=0; i < rpath.length; i++) {
           headMovement += Math.abs(rpath[i]-prev);
            prev = rpath[i];
        }
        return headMovement;
    }
   
    public int[] path(){
       int [] resultPath = new int[queue.length];
       for (int i = 0; i < queue.length; i++){
        resultPath[i] = queue[i];
    }
       return resultPath;
    }
   
    public void println(){
    System.out.println("FCFS head movement = " + serviceRequests());
       
        System.out.print("FCFS Path = ");
        for(int i: path()){
            System.out.print(i + " "); 
        }
        System.out.println("");
}
}

Bibliography

Operating System Concepts with Java, Avi Silberschatz, Peter Baer Galvin, Greg Gagne

Moving files in Java

Assignment

Design an algorithm for moving one file, that is copying a file from a source (a directory) to another source, and deleting the original. Consider that folders are files, too.

 

 Step 1: Build a simple working program ([1])

 

import java.io.*;

public class mv{
public static void main(String args[]){
         try{
         // File (or directory) to be moved
         File file = new File("C:\\ProgrameJava\\file.txt");
       
         // Destination directory
         File dir = new File("C:\\ProgrameJava\\myDir");
       
         // Move file to new directory
         boolean success = file.renameTo(new File(dir, file.getName()));
             if (!success) {
             System.out.println("File not moved");
         }
     }
         catch (Exception ioe){
         ioe.printStackTrace();
     }
}
}

Step 2: Add code to check if source and destination exist, and print appropriate messages on the application console

 

Step 3: Give the names of the source and the destination as command line arguments

 

Step 4: Use FileInputStream and FileOutputStream to move the file ([4])

 

Bibliography

1. http://www.java.happycodings.com/Core_Java/code50.html
2. http://docs.oracle.com/javase/tutorial/essential/io/move.html
3. http://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html#move%28java.nio.file.Path,%20java.nio.file.Path,%20java.nio.file.CopyOption...%29
4. http://myflex.org/yf/java/slides/Unit8.pdf
5. http://stackoverflow.com/questions/300559/move-copy-file-operations-in-java