Reg: ArrayList

Hi All,
I have a ArrayList in my application and some objects are added to that arraylist for ex: "arr.add("document"); 
I am unable to understand the concept of this arraylist. What type of attributes can be added to arraylist.
Thanks in advance.

Hi Bharath,
                  Check this:
<a href="http://java.sun.com/j2se/1.4.2/docs/api/java/util/ArrayList.html">http://java.sun.com/j2se/1.4.2/docs/api/java/util/ArrayList.html</a>
regards
Sumit

Similar Messages

  • ArrayList e .RangeCheck(int)line 546

    Hi guys I am working on this project
    in few word
    I have to draw different shape on a panel
    moreover when two similar shapes collide ( 2 circles ) they make a bigger circle
    when st change direction
    almost everything works
    import java.awt.Graphics;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.util.ArrayList;
    import java.util.Comparator;
    import java.util.Iterator;
    import javax.swing.JPanel;
    class ShapePanel extends JPanel implements ActionListener {
         private static final long serialVersionUID = 1L;
         public static ArrayList <Shape>shapes;
         private javax.swing.Timer animationTmr;
         int speed;
         PlaySound audioClip = new PlaySound();
         private float heigth;
         private float width;
         private int shape1;
         private int shape2;
         public ShapePanel() {
              shapes = new ArrayList<Shape>();
              animationTmr = new javax.swing.Timer(80, this); //interval, ActionListener
              animationTmr.start();
         public ArrayList<Shape> getShapes()
              return shapes;
         public void addSquare(int x, int y,int w,int h, int shapeType) {
              shapes.add(new Square(this,x, y,width, heigth, shapeType));
              repaint();
              System.out.println(shapes.size());
         public void addCircle(int x, int y,int w,int h, int shapeType) {
              shapes.add(new Circle(this, x, y,width, heigth, shapeType));
              repaint();
              System.out.println(shapes.size());
         public void addRectangle(int x, int y,int w,int h,  int shapeType) {
              shapes.add(new Rectangle(this, x, y,width, heigth, shapeType));
              repaint();
              System.out.println(shapes.size());
         public void addStar(int x, int y,int w,int h, int shapeType) {
              shapes.add(new Star(this, x, y,width, heigth, shapeType));
              repaint();
              System.out.println(shapes.size());
         public void paintComponent(Graphics g) { //called Whenever panel needs
              super.paintComponent(g); //re-displaying:
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              g.fillRect(0, 0, this.getWidth(), this.getHeight());
              while (it.hasNext()) { //each one's paint method
                   it.next().paint(g);
         public void actionPerformed(ActionEvent ev) {      
              //On timer tick,
              Iterator<Shape> it = shapes.iterator(); //Iterate through Balls calling
              while (it.hasNext()) { //each one's updatePos() method
                   it.next().updatePos();
              checkTypeCollision();
              handleCollision();
              repaint();
        private void checkTypeCollision()
              //we iterate through all the balls, checking for collision
              for(int i=0;i<shapes.size();i++)
                   for(int j=0;j<shapes.size();j++)
                             if(i!=j)
                                  if(collide(shapes.get(i), shapes.get(j)))
                                            shape1=shapes.get(i).shapeType;
                                            shape2=shapes.get(j).shapeType;
                                             if(shape1==shape2)
                                             /*     int     newX = (int) ((shapes.get(i).getCenterX() + (shapes.get(j).getCenterX()/2))/2);
                                                  int newY = (int) ((shapes.get(i).getCenterY() + (shapes.get(j).getCenterY() /2))/2);
                                                 float newWidth =   shapes.get(i).getWidth()+(shapes.get(j).getWidth()/2);
                                                 float newHeigth = shapes.get(i).getHeigth()+(shapes.get(j).getHeigth()/2);
                                                 int newShapeType = shapes.get(i).shapeType;
                                                       if(shapes.get(i).getShapeType()==1)
                                                            shapes.remove(j); //remove shape element at j
                                                            shapes.remove(i); //remove shape element at j
                                                            System.out.println("SIZE IS==="+     shapes.size());
                                                            System.out.println("newx====="+newX);
                                                            System.out.println("newy====="+newY);
                                                            System.out.println("newWidth====="+newWidth);
                                                            System.out.println("newx====="+newHeigth);
                                             //               shapes.add(new Rectangle(this,newX,newY,530,530,newShapeType));
                                                            System.out.println("SIZE IS==="+     shapes.size());
                                                       //     repaint();
                                                       if(shapes.get(i).getShapeType()==2)
                                                            shapes.remove(j); //remove shape element at j
                                                            shapes.remove(i); //remove shape element at j
                                                  //          shapes.add(new Circle(this,newX,newY,newWidth,newHeigth,newShapeType));
                                                       //     repaint();
                                                       if(shapes.get(i).getShapeType()==3)
                                                            shapes.remove(j); //remove shape element at j
                                                            shapes.remove(i); //remove shape element at j
                                                            shapes.add(new Square(this,newX,newY,newWidth,newHeigth,newShapeType));
                                                       if(shapes.get(i).getShapeType()==3)
                                                            shapes.remove(j); //remove shape element at j
                                                            shapes.remove(i); //remove shape element at j
                                                            //shapes.add(new Star(this,newX,newY,newWidth,newHeigth,newShapeType));
                                                       //     repaint();
         private void handleCollision()
              //we iterate through all the balls, checking for collision
              for(int i=0;i<shapes.size();i++)
                   for(int j=0;j<shapes.size();j++)
                             if(i!=j)
                                  if(collide(shapes.get(i), shapes.get(j)))
                                        shapes.get(i).hit(shapes.get(j));
                                       shapes.get(j).hit(shapes.get(i));                                   
         boolean collide(Shape b1, Shape b2)
              double wx=b1.getCenterX()-b2.getCenterX();
              double wy=b1.getCenterY()-b2.getCenterY();
              //we calculate the distance between the centers two
              //colliding balls (theorem of Pythagoras)
              double distance=Math.sqrt(wx*wx+wy*wy);
              if(distance<b1.shapeSize)     
                   audioClip.playRectangle();
                   return true;          
                   else return false;     
         public static int vectorSize()
              return shapes.size();
    }the drawing stops and
    i have this error after a while
    arrayList<e>.RangeCheck(int)line 546
    moreover it doesn t draw a bigger shape as i want with the line
    shapes.add(new Circle(this,newX,newY,newWidth,newHeigth,newShapeType));
                                                       help please the deadline is Tomorrow;

    Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 4, Size: 4
         at java.util.ArrayList.RangeCheck(ArrayList.java:546)
         at java.util.ArrayList.get(ArrayList.java:321)
         at ShapePanel.checkTypeCollision(ShapePanel.java:156)
         at ShapePanel.actionPerformed(ShapePanel.java:77)
         at javax.swing.Timer.fireActionPerformed(Timer.java:271)
         at javax.swing.Timer$DoPostEvent.run(Timer.java:201)
         at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
         at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
         at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
         at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
         at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
         at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
         at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
    it doesn t compile because is part of a bigger project

  • Check for null and empty - Arraylist

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    Greeshma...

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  • Problem getting arraylist values from request

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    java syntax == EL syntax
    request.getParameter("myparameter") == ${param.myparameter}
    request.getAttribute("myAttribute") == ${requestScope.myAttribute}
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    evnafets

  • How to input data into an arraylist from a text file?

    I am trying to take data from a text file and put that data into an arraylist. First here is the text file:
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    import java.io.*;
    import java.util.Scanner;
    import java.util.ArrayList;
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         public int toAdd = 0;
         private boolean done = false;               //Are we done yet?
         public String strItemName;                    //The name of the item type.
         public int intNumInStock;                    //The number in stock of that type.      
         public double dblValueOfOneItem;          //The value of one item.
        public String strNumberInStock;               
        public double dblTotalValueA;               //The total value of warehouse A.
        public double dblTotalValueB;               //The total value of warehouse B.
        public double dblTotalValueC;               //The total value of warehouse C.
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        public int intWarehouseBItemCount;          //Counter for items in warehouse B.
        public int intWarehouseCItemCount;          //Counter for items in warehouse C.
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         ArrayList warehouseBList = new ArrayList(); //Create the Warehouse B arrayList.
         ArrayList warehouseCList = new ArrayList(); //Create the Warehouse C arrayList.
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              String strValueOfOneItem = Double.toString(dblValueOfOneItem);
              this.strNumberInStock = strNumInStock;
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              warehouseAList.add(this.strNumberInStock);
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              String strValueOfOneItem = Double.toString(dblValueOfOneItem);
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              warehouseCList.add(this.strItemName);
              warehouseCList.add(this.strNumberInStock);
              warehouseCList.add(this.dblValueOfOneItem);
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                   System.out.print(">");
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                    if (cmd.equals("help"))
                         this.displayHelp();
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                    else if (cmd.equals("F") && line.hasNext())
                         this.inputFromFile(line.next());
                    else if (cmd.equals("K") && line.hasNext())
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           *     @param inputFile; The name of the input file to process.*/
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               System.out.println("!Using input file " + inputFile + ".");
               System.out.print("!Enter the name of the output file: ");
               String outputFile = cin.next();
               System.out.println("!Using output file " + outputFile + ".");
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                   //Scanner in = new Scanner(new File(inputFile));
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                   String line1 = null;
                   String line2 = null;
                   String line3 = null;
                   String line4 = null;
                   String line5 = null;
                   String line6 = null;
                   String line7 = null;
                   String line8 = null;
                   String line9 = null;
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                   //System.out.println((char)(char)in.read() + " experiment");
                   /**This loop assigns values to the string variables based on the
                    * values on each line in the input file. */
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                        line2 = in.readLine();
                        line3 = in.readLine();
                        line4 = in.readLine();
                        line5 = in.readLine();
                        line6 = in.readLine();
                        line7 = in.readLine();
                        line8 = in.readLine();
                        line9 = in.readLine();
                   //Print the contents of each line in the input file.
                   System.out.println("!value of line 1: " + line1);
                   System.out.println("!value of line 2: " + line2);
                   System.out.println("!value of line 3: " + line3);
                   System.out.println("!value of line 4: " + line4);
                   System.out.println("!value of line 5: " + line5);
                   System.out.println("!value of line 6: " + line6);
                   System.out.println("!value of line 7: " + line7);
                   System.out.println("!value of line 8: " + line8);
                   System.out.println("!value of line 9: " + line9);
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                   warehouseAList.add(line1);
                   warehouseBList.add(line4);
                   warehouseCList.add(line7);
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                   int intLine2 = Integer.valueOf(line2).intValue();
                   this.intWarehouseAItemCount = intLine2;
                   double dblLine3 = Double.valueOf(line3).doubleValue();
                   this.dblTotalValueA = dblLine3;
                /**Add the item count and total value for warehouse B.*/
                   int intLine5 = Integer.valueOf(line5).intValue();
                   this.intWarehouseBItemCount = intLine5;
                   double dblLine6 = Double.valueOf(line6).doubleValue();
                   this.dblTotalValueB = dblLine6;
                /**Add the item count and total value for warehouse C.*/
                  int intLine8 = Integer.valueOf(line8).intValue();
                  this.intWarehouseCItemCount = intLine8;
                  double dblLine9 = Double.valueOf(line9).doubleValue();
                  this.dblTotalValueC = dblLine9;
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                  String toAddOrDel = cin.next();
                /**Print the contents of all the warehouses. */
                   System.out.println(" ");
                   //Print the contents of warehouse A.
                   System.out.println("!--------------------------------");
                   System.out.println("!----------Warehouse A:----------");
                   System.out.println("!--------------------------------");
                   //Print the item list for warehouse A.
                   System.out.println(warehouseAList);
                   //Print the total amount of items in warehouse A.
                   System.out.println("Total items: " + this.intWarehouseAItemCount);
                   //Print the total value of the items in warehouse A.
                   System.out.println("Total value: " + this.dblTotalValueA);
                   System.out.println("!--------------------------------");
                   System.out.println("!----------Warehouse B:----------");
                   System.out.println("!--------------------------------");
                   //Print the item list for warehouse B.
                   System.out.println("!warehouseB: " + warehouseBList);
                   //Print the total amount of items in warehouse B.
                   System.out.println("Total items: " + this.intWarehouseBItemCount);
                   //Print the total value of the items in warehouse B.
                   System.out.println("Total value: " + this.dblTotalValueB);
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                    //Write the total value for warehouse B.
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               //Display total value of warehouse B.
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               System.out.println("!--------------------------------------------------");
               System.out.println("!------------------Warehouse C:--------------------");
               System.out.println("!--------------------------------------------------");
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               System.out.println(warehouseCList);
               //Total items in warehouse C.
               System.out.println("Total items: " + intWarehouseCItemCount);
               //Display total value of warehouse C.
               System.out.println("Total value: " + "$" + dblTotalValueC);
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              System.out.println("!--------------------------------");
              System.out.println("! ");
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              System.out.println("!---------------------------------------");
              System.out.println("! ");
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                   //Warehouse B BufferedReader.
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                   //Warehouse C BufferedReader.
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                   String lineB = null;
                   String lineC = null;
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                   String line2 = null;
                   String line3 = null;
                   String line4 = null;
                   String line5 = null;
                   String line6 = null;
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    As I said in my original posting, I am refactoring code from one of the O'Reilly books for an assignment. So no, this isn't all my code, just some of it (copyright is duly noted in my assignment).
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    - use nextDouble() as nextFloat() is less accurate (I am guessing not a problem here)]
    - don't use pic.clone(), just create a new array at the start of each loop.

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