Traffic Light System

السلام عليكم

على ما أعتقد أن الخطأ يا أختي هو أنك لم تكتبي الـ class الذي تريدين التوريث منه بعد كلمة extends

تحياتي

اهلا بك اخي الكريم ,,

الكلاس الذي اريد التوريث منه موجود ولكن لا جدوى في ذلك :(

public class trafficControl extends implements Runnable

أختي الجمله السابقه لا يوجد فيها اسم الكلاس المراد التوريث منه

حاولت اغير بس مافي فايده :( :(

بلييييييييييز مساعده تسليمه بكره :(

انت شغاله عليه بالـ JFrame؟؟؟؟

import java.awt.*;
import java.util.*;

import javax.swing.JApplet;
import javax.swing.JFrame;

public class trafficControl extends JApplet implements Runnable{
Dimension offDimension;
Image bgImage,fgImage;
Light L;
Traffic T;
TextField countText,scoreText,XYpos;
int numLight=3,numSection=numLight+1;
String rts,STR[]={"Reset","Start","Time","maxVelocity","Acceleration","delayTime"};
Color bgColor=new Color(0xC8,0xDF,0xD0);
public void init(){
  setBackground(bgColor);
  for(int i=0;i<STR.length;i++){
   if((rts=getParameter(STR))!=null)
	STR=new String(rts);
  }
  Panel p=new Panel();
  p.add(new Label("N1/N2"));
  p.add(countText=new TextField("0/0/0.00",12));
  countText.setEditable(false);
//  p.add(new Label("T="));
//  p.add(timeText=new TextField("0",3));
//  timeText.setEditable(false);
  p.add(new Label("n1/n2"));
  p.add(scoreText=new TextField("0/0/0.00",9));
  scoreText.setEditable(false);
  p.add(new Button(STR[1]));
  p.add(new Button(STR[0]));
  add("North",p);
  L=new Light(numLight,STR);
  T=new Traffic(L);
  String str;
  if((str=getParameter("accelerationValue"))!=null)
   T.a=Double.valueOf(str).doubleValue();
  if((str=getParameter("vmax"))!=null)
   car.vmax=Double.valueOf(str).doubleValue();
  reset();
}

public boolean action(Event ev, Object arg) {
  String label = (String)arg;
  if (ev.target instanceof Button) {
   if(label.equals(STR[1])){
	start();
   }else if(label.equals(STR[0])){
	reset();
   }
   return true;
  }
  return false;
}

Graphics g,g0;
Dimension area;
void reset(){
  //stop();
  area=size();
  if ( (g == null) ){
//	|| (area.width != bgDimension.width)
//	|| (area.height != bgDimension.height) ) {
//   bgDimension = area;
   bgImage = createImage(area.width, area.height);
   fgImage = createImage(area.width, area.height);
   g = bgImage.getGraphics();
   g0=fgImage.getGraphics();//getGraphics();
  }
  g.setColor(bgColor);
  g.fillRect(0,0,area.width,area.height);
  g.setColor(Color.black);
  drawRoad(area);
}
numberInput maxV,acceleration;
void drawRoad(Dimension area){
  L.init(g,area);
  T.init(g0,L.X[0],L.y-5,area.width);
  maxV=new numberInput(g,5,L.y,STR[3]);
  maxV.setValue((int)car.vmax,5,50);
  acceleration=new numberInput(g,5,L.y+L.lSize.height,STR[4]);
  acceleration.setValue((int)T.a,1,20);
  repaint();
}
static boolean running,rightClick,changed=false;
public boolean mouseDown(Event e, int x, int y){
  if(e.modifiers==Event.META_MASK)//"Right Click, ";
   rightClick=true;
  else rightClick=false;
  int w=L.lSize.width;
  if(L.mouseDown(e,x,y)){
   repaint();
   return true;
  }else if(x< 2*w && y<3*w){
   int sign=0;
   if(e.modifiers==Event.META_MASK || x>w)sign=1;//right click
   else if((L.greenTime>1)&&
	  (L.yellowTime-L.greenTime)>1 &&
	  (L.redTime-L.yellowTime)>1 )
	  sign=-1; // right click add 1, left click sub 1

   switch(y/w){
	case 0:L.greenTime+=sign;
	case 1:L.yellowTime+=sign;
	case 2:L.redTime+=sign;
   }
   L.setupLightTime(L.greenTime,L.yellowTime,L.redTime);
   repaint();
  }else if(maxV.mouseDown(e,x,y)){
   car.vmax=maxV.value();
   repaint();
  }else if(acceleration.mouseDown(e,x,y)){
   T.a=acceleration.value();
   repaint();
  }else{
   running=!running;
   changed=true;
   repaint();
  }
  return true;
}
//public boolean mouseDrag(Event e, int x, int y){
  //if(e.modifiers==Event.META_MASK)return true;
// return true;
//}
public boolean mouseUp(Event e, int x, int y){
  if(changed){
   if(!rightClick)running=!running;
   changed=false;
  }
  return true;
}
//public boolean mouseMove(Event e, int x, int y){
// XYpos.setText(String.valueOf(x)+","+String.valueOf(y));
// return true;
//}
public void paint(Graphics gs){
  if(g==null)reset();
  update(gs);
}
String d2String(double value){
  float f=(float)((int)(value*100.)/100.);
  String str=String.valueOf(f);
  if(str.indexOf(".")==-1)str+=".0";
  return str;
}

public void update(Graphics gs){
  g0.drawImage(bgImage, 0, 0, this);
  if(!running)L.drawTrace(g0,acceleration.value(),maxV.value());
  T.advanced(deltaT);
  T.drawVelocity(g0);
  g0.drawString(STR[2]+d2String(runTime)+" s",130,L.y-L.height);
  gs.drawImage(fgImage, 0, 0, this);
}
// animation code
Thread animThread;
long lastTime=0;
double runTime;
long delay=50,delta;
//  This starts the threads.
public void start(){
  //Start animating!
  if (animThread == null) {
   animThread = new Thread(this);
   animThread.start();
   //Remember the starting time. of thread
   lastTime = System.currentTimeMillis();
   runTime=0.;
  }
  running=true;
}
  public void stop() {
  //Stop the animating thread.
  animThread = null;
}
int second=0;
public void run() {
  //Just to be nice, lower this thread's priority
  Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
  //This is the animation loop.
  while (Thread.currentThread() == animThread) {
   //Advance the animation frame. with delta time
   delta=System.currentTimeMillis()-lastTime;
   lastTime+=delta;
   if(running)advanced(delta/1000.);
   try {
	animThread.sleep(Math.max(0,lastTime-System.currentTimeMillis()));
   } catch (InterruptedException e) {
	break;
   }
  }
}
int lastN1=0,lastN2=0,period=100;
String str="(0/0)=>";
void showResult(){
  countText.setText(String.valueOf(T.passed)+"/"+
	String.valueOf(T.passed2)+"/"+
	String.valueOf((int)(100.*(T.passed+T.passed/3.)/second)/50.));
  //period=3*(L.redTime);
  if(second%period==0){
  double score=(T.passed-lastN1+(T.passed2-lastN2)/3.)/period;
  scoreText.setText(String.valueOf(T.passed-lastN1)+"/"+
	String.valueOf(T.passed2-lastN2)+"/"+
	String.valueOf((int)(100.*score)/50.));
   lastN1=T.passed;
   lastN2=T.passed2;
  }
}
double deltaT;
void advanced(double dt){
  runTime += dt;
  int t=(int)runTime;
  L.setStatus(t);
//  T.advanced(dt);
  deltaT=dt;
  if(t!=second){
   second=t;
   //timeText.setText(String.valueOf(second));
   showResult();
  }
  repaint();
}
}

class Light{// implements Runnable{
static int green=0,yellow=1,red=2,count;
Color color[]={Color.green,Color.yellow,Color.red};
int X[],status[],y;
static int height=70;
int greenTime,yellowTime,redTime;
int delayArray[];
Dimension lSize=new Dimension(10,30);
Graphics g;
int dd=3;
numberInput delayControl[];
int init_delay=4;
String STR[];
Light(int n,String s[]){
  count=n;
  X=new int[n];
  status=new int[n];
  delayArray=new int[n];
  delayControl=new numberInput[n-1];
  STR=s;
}
int xx,yy,size,size2;
int width,roadWidth;
void init(Graphics gi,Dimension area){
  roadWidth=15;
  width=(area.width-count*roadWidth)/count;
  int x0=width/2,dx=width+roadWidth,y0=area.height;
  height=(area.height-3*lSize.height/2-roadWidth)/2;
  g=gi;
  y=y0-height;
  xx=lSize.width+dd;
  yy=y+dd;
  size=lSize.width/2;
  size2=2*size;
  drawRoad(width,roadWidth);// draw streets
  for(int i=0;i<count;i++){
   X=x0+i*dx;
   status=red;
   delayArray=0;
   drawLight(i);
  }
  // draw Left top cornor light
  Color c=g.getColor();
  g.drawRect(0,0,lSize.width,lSize.height);
  for(int i=0;i<3;i++){// 3 lights
   g.setColor(color);
   g.fillOval(0,i*lSize.width,size2,size2);
   g.setColor(Color.black);
   g.drawOval(0,i*lSize.width,size2,size2);
  }
  g.setColor(c);
  setupLightTime(20,25,40);
  for(int i=1;i<count;i++){ // delay control init
   delayControl[i-1]=new numberInput(g,X-lSize.width-5,yy,STR[5],true);
  }
}
void drawRoad(int width,int roadWidth){
  int x=0;
  int w,h=height,dh=h+roadWidth;
  //int dd=5;
  //int xx=lSize.width+dd,yy=dd;
  for(int i=0;i<count+1;i++){ //draw street
   if(i==count || i==0 )w=width/2;
   else w=width;
   g.drawRect(x,y,w,h-1); // lower part
   g.drawRect(x,y-dh,w,h); // upper part
   for(int j=y-dh+h;j>y-dh;j-=10)g.drawLine(x,j,x+5,j);
   for(int j=y-dh+h;j>y-dh;j-=20)g.drawLine(x+5,j,x+10,j);
   x=x+w+roadWidth;
  }
}

public boolean mouseDown(Event e, int x, int y){
  for(int i=1;i<count;i++){ // delay control
   if(delayControl[i-1].mouseDown(e,x,y)){
	setupDelay(i,delayControl[i-1].lastChange());
	return true;
   }
  }
  return false;
}

void drawLight(int n){
  // draw Light according to current status
  Color c=g.getColor();
  int x1=X[n]-xx;
  g.clearRect(x1,yy,lSize.width,lSize.height);
  g.drawRect(x1,yy,lSize.width,lSize.height);
  for(int i=0;i<3;i++)
   g.drawOval(x1,yy+i*lSize.width,size2,size2);
  g.setColor(color[status[n]]);
  g.fillOval(x1,yy+status[n]*lSize.width,size2,size2);
  g.setColor(c);
}
void setupLightTime(int tGreen,int tYellow, int tRed){
  greenTime=tGreen;
  yellowTime=tYellow;
  redTime=tRed;
  g.clearRect(2*size2,0,30,3*size2);
  Color c=g.getColor();
  g.setColor(Color.black);
  g.drawString(String.valueOf(greenTime),2*size2,size2);
  g.drawString(String.valueOf(yellowTime-greenTime),2*size2,2*size2);
  g.drawString(String.valueOf(redTime-yellowTime),2*size2,3*size2);
  //drawTiming(running);
  g.setColor(c);
}
void drawTrace(Graphics gp,double a,double maxV){
  int xi=width/2+1,xx=xi;
  int yi=y+height;
  double x=0.;//,vx=0.;
  double t,ta=maxV/a,ta2=ta*ta;
  a=a/2.;
  Color c=gp.getColor();
  drawTiming(gp);
  gp.setColor(Color.blue);
  for(t=0.;yi>y-height;t+=0.5){
   if(t<ta)gp.drawLine(xx,yi,xx=xi+(int)(a*t*t),yi--);
   else gp.drawLine(xx,yi,xx=xi+(int)(a*ta2+maxV*(t-ta)),yi--);
   //if(t<ta)gp.drawLine(xx=xi+(int)(a*t*t),yi--,xx,yi);
   //else gp.drawLine(xx=xi+(int)(a*ta2+maxV*(t-ta)),yi--,xx,yi);
  }
  gp.setColor(c);
}
void drawTiming(Graphics gp){
  //draw light timing info
  Color c=gp.getColor();
  int xi=width/2,yi;
  for(int i=0;i<count;i++){
   gp.setColor(Color.white);
   gp.drawLine(xi,y+height,xi,y-height);
   //if(status){
   // gp.setColor(Color.black);
   // gp.drawLine(xi,y+height,xi,y);
   // gp.drawLine(xi,y-roadWidth,xi,y-height);
   //}else{
	yi=y+height-2*delayArray;
	while(yi>y-height){
	 gp.setColor(Color.green);
	 gp.drawLine(xi,yi,xi,yi-=2*greenTime);
	 gp.setColor(Color.yellow);
	 gp.drawLine(xi,yi,xi,yi-=2*(yellowTime-greenTime));
	 gp.setColor(Color.red);
	 gp.drawLine(xi,yi,xi,yi-=2*(redTime-yellowTime));
	}
	yi=y+height-2*delayArray;
	while(yi<y+height){
	 gp.setColor(Color.red);
	 gp.drawLine(xi,yi,xi,yi+=2*(redTime-yellowTime));
	 gp.setColor(Color.yellow);
	 gp.drawLine(xi,yi,xi,yi+=2*(yellowTime-greenTime));
	 gp.setColor(Color.green);
	 gp.drawLine(xi,yi,xi,yi+=2*greenTime);
	}
   //}
   xi+=width+roadWidth;
  }
  gp.setColor(c);
}

void setupDelay(int id,int Time){
  for(int i=id;i<count;i++)delayArray+=Time;
  //drawTiming(running);
}

public int height(){ return height;}

boolean setStatus(long t){
  boolean out=false;
  long dt;
  int s;
  for(int i=0;i<count;i++){
   s=status;
   dt=(t-delayArray) % redTime;
   if(dt<0)dt+=redTime;
   if(dt<greenTime)status=green;
   else if(dt<yellowTime)status=yellow;
   else status=red;
   if(s!=status){
	out=true;
	drawLight(i);
   }
  }
  return out;
}
}

class numberInput {
int width,height,xs,ys,x,y;
String title;
Graphics g;
int value=0;
double scale=1.;
Rectangle add,sub;
int change=0;
boolean bounded=false;
int min=0,max=100;
int xwidth=60;
numberInput(Graphics gs,int xi,int yi,String s,boolean rightAlign){
  g=gs;x=xi;y=yi;title=s;
  FontMetrics fm=g.getFontMetrics();
  if(rightAlign)x-=xwidth;//fm.stringWidth(title);
  init();
}
numberInput(Graphics gs,int xi,int yi,String s){
  g=gs;x=xi;y=yi;title=s;
  init();
}
void init(){
  FontMetrics fm=g.getFontMetrics();
  int h=fm.getHeight(),w=xwidth;//fm.stringWidth(title);
  int h2=h/2;
  width=w-h-2;
  height=h;
  int yy=y+h;
  g.drawString(title,x,yy);
  yy+=1;
  int xa[]={x,x+h2,x+h2},xb[]={x+w,x+w-h2,x+w-h2};
  int yab[]={yy+h2,yy,yy+h};
  xs=x+h2+3;
  ys=yy+h-2;
  g.drawRect(xs-2,ys-height+2,width-1,height);
  g.fillPolygon(xa,yab,3);
  g.fillPolygon(xb,yab,3);
  sub=new Rectangle(x,y+h+1,h2,h);
  add=new Rectangle(x+w-h2,y+h+1,h2,h);
  setValue(0);
}
void setValue(int i,int mi,int mx){
  setValue(i);
  bounded=true;
  min=mi;
  max=mx;
}
void setValue(int i,int s){
  scale=10^s;
  setValue(i);
}

void setValue(int i){
  value=i;
  g.clearRect(xs-2+1,ys-height+3,width-3,height-2);
  Color c=g.getColor();;
  g.setColor(Color.black);
  g.drawString(String.valueOf(i*scale),xs,ys);
  g.setColor(c);
}
boolean valueChange(int di){
  if(bounded &&( (value==min && di<0) || (value==max && di>0)))di=0;
  if(di==0)return false;
  value+=change;
  setValue(value);
  return true;
}
int lastChange(){ return change;}
double value(){ return scale*value;}

public boolean mouseDown(Event e, int x, int y){
  if(add.inside(x,y))change=1;
  else if(sub.inside(x,y))change=-1;
  else change=0;
  return valueChange(change);
}
}

class Traffic {//implements Runnable{
// traffic control center
Vector v=new Vector(); // main traffic
Vector v2[]; // other traffics
car c;
int w=10,h=5,y0,w2=w/2;
Graphics g;
static double a=10.;
static private double a2=a/6.;
int minDx=3,xMax,Dx,Dx2,minDx2;
Light L;
int passed=0,passed2=0;
int ymax,ymin,y1;
Traffic(Light Li){
  L=Li;
  v2=new Vector[L.count];
  for(int i=0;i<L.count;i++)v2=new Vector();
}

double roadWidth=15.;
void init(Graphics gs,int x,int y,int xmax){
  passed=0;
  passed2=0;
  a2=a/6.;
  g=gs;
  xMax=xmax+w+minDx;
  y0=y;
  Dx=w+minDx;
  Dx2=Dx+minDx;
  minDx2=2*minDx;
  reset();
  v.removeAllElements();
  for(int i=0;x>0;i++,x-=Dx){
   c=new car((double)(x),0.,0.);
   if(i==0)c.setFront(true);
   else c.setFront(false);
   v.addElement(c);
   drawCar(c,false);
  }
  // for vertical cars
  ymax=y0+L.height();
  ymin=y0-(int)roadWidth-L.height();
  for(int i=0;i<L.count;i++){
   v2.removeAllElements();
   int sign=1-2*(i%2);
   int n=L.height()/Dx;
   y1=y0-(int)roadWidth;
   for(int j=0;j<n;j++){
	c=new car(y1-j*Dx,0.,0.);
	if(j==0)c.setFront(true);
	 else c.setFront(false);
	v2.addElement(c);
	drawCar(c,L.X,sign,false);
   }
  }
  // draw car color code
  int xx=15,yy=ymin+15,xx2=xx+w+h;
  g.setColor(Color.black);
  g.drawRect(xx,yy,w,h);
  g.drawString("a>0.",xx2,yy+h);
  g.setColor(Color.yellow);
  g.fillRect(xx,yy,w,h);
  yy+=w;
  g.setColor(Color.black);
  g.drawRect(xx,yy,w,h);
  g.drawString("a=0.",xx2,yy+h);
  g.setColor(Color.green);
  g.fillRect(xx,yy,w,h);
  yy+=w;
  g.setColor(Color.black);
  g.drawRect(xx,yy,w,h);
  g.drawString("a<0.",xx2,yy+h);
  g.setColor(Color.red);
  g.fillRect(xx,yy,w,h);
  g.setColor(Color.black);
}

void reset(){
  g.clearRect(0,y0-h,xMax,h+1);
}
void drawCar(car c,int x,int sign,boolean erase){
   int xx=x+w2,yy=(int)c.y[0]-w2;
   if(sign==-1)yy=ymin+ymax-yy;
   if(erase)g.clearRect(xx,yy,h+1,w+1);
   else {
	g.drawRect(xx,yy,h,w);
	Color color=g.getColor();
	if(c.acceleration==0.)g.setColor(Color.green);
	else if(c.acceleration<0)g.setColor(Color.red);
	else g.setColor(Color.yellow);
	g.fillRect(xx,yy,h,w);
	g.setColor(color);
   }
}

void drawCar(car c,boolean erase){
   if(erase)g.clearRect((int)c.y[0]-w,y0-h,w+1,h+1);
   else {
	g.drawRect((int)c.y[0]-w,y0-h,w,h);
	Color color=g.getColor();
	if(c.acceleration==0.)g.setColor(Color.green);
	else if(c.acceleration<0)g.setColor(Color.red);
	else g.setColor(Color.yellow);
	g.fillRect((int)c.y[0]-w,y0-h,w,h);
	g.setColor(color);
   }
}
// traffic flow control
car cs;
boolean nextFront;
void advanced(double dt){
  cs=null;
  c=(car)v.firstElement();
  c.setAcceleration(a);
  if(c.y[0]>xMax){// remove car outside boundary
   v.removeElement(c);
   passed+=1;
   drawCar(c,true);
   c=null;
  }
  nextFront=false;
  int count2=L.count;
  double aNeeded,tReact=1.;
  double minD=Dx,safeD=2.*Dx;
  for(Enumeration e=v.elements();e.hasMoreElements();){
   c=(car)e.nextElement();
   if(c.lightID<count2){// before last light
	if(cs!=null){
	 minD=cs.y[0]-c.y[0]-Dx;
	 safeD=minD-c.y[1]*tReact;
	 if(minD<0.)c.y[1]=cs.y[1];// too close
	}else{
	 minD=Dx;
	 safeD=2.*Dx;
	}
	if((cs!=null)&& safeD<0.){ // be safe
	   aNeeded=2.*(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/minD;//(cs.y[0]-c.y[0]-Dx);
	   //aNeeded=a;
	   c.setAcceleration(aNeeded);
	}else{
	 switch(L.status[c.lightID]){
	 case 0: // green light
	  if(cs!=null && minD>2.*minDx)c.setAcceleration(a);
	 break;
	 case 1: //yellow
	  if(L.X[c.lightID]-c.y[0] < c.y[1]*c.y[1]/(3.*Math.max(a,10.)))break;
	 case 2:
	  if(c.isFront()){
	   if(L.X[c.lightID]-c.y[0] > 2.*Dx2)
		c.setAcceleration(a);
	   else if(L.X[c.lightID]-c.y[0] < minDx){
		c.y[1]=0.;
		c.setAcceleration(0.);
	   }else {
		aNeeded=c.y[1]*c.y[1]/(L.X[c.lightID]-c.y[0]);
		c.setAcceleration(-aNeeded);
	   }
	  }else if(cs!=null){
	   if(safeD > Dx2)c.setAcceleration(a);
	   else if(cs.acceleration<0. && c.acceleration>0.){
		aNeeded=(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/minDx;//(cs.y[0]-c.y[0]);
		c.setAcceleration(aNeeded);
	   }else c.setAcceleration(0.);
	  }
	  break;
	 }
	}
	if(c.y[0]>=L.X[c.lightID]){
	 c.lightID+=1; //just pass one traffic light
	 nextFront=true;
	}else if((c.y[0]<L.X[c.lightID])&&(nextFront)){
	  c.setFront(true);
	  nextFront=false;
	}

   } else c.setAcceleration(a);

   // advanced one time step
   //drawCar(c,true);
   c.advanced(dt);
   drawCar(c,false);
   cs=c;
  }
  if((int)c.y[0]>Dx){
   v.addElement(new car(0.,0.,a));
   drawCar(c,false);
  }
  advanced2(dt);
}

void advanced2(double dt){
  // if passed lighID=1;
  int sign;
  for(int i=0;i<L.count;i++){
   c=(car)v2.firstElement();
   cs=null;
   sign=1-2*(i%2);
   if(c.y[0]>ymax){
	v2.removeElement(c);
	passed2+=1;
	drawCar(c,L.X,sign,true);
	c=null;
   }
   nextFront=false;
   for(Enumeration e=v2.elements();e.hasMoreElements();){
	c=(car)e.nextElement();
	if(c.lightID==0){// not pass light yet
	 if(c.y[0]<=y1){
	  if(nextFront){
	   c.setFront(true);
	   nextFront=false;
	  }
	 }else{
	  c.lightID+=1; //just pass one traffic light
	  c.setAcceleration(a);// keep accelerating
	  nextFront=true;
	  if(cs!=null)c.setFront(false); // first car, always front
	 }
	 double aNeeded=a;
	 if(L.status==2){ // red light, green for us
	  if(cs==null)c.setAcceleration(a);
	  else if((cs.y[0]-c.y[0]) > Dx2 )
	   c.setAcceleration(a);
	 }else { // green or yellow light, red for us
	  if(c.isFront()){
	   if(y1-c.y[0] < minDx){
		c.y[1]=0.;
		c.setAcceleration(0);
	   }else{
		aNeeded=c.y[1]*c.y[1]/(y1-c.y[0]);
		c.setAcceleration(-aNeeded);
	   }
	  }else if(cs!=null){
	   if(cs.y[0]-c.y[0] > Dx2)
		c.setAcceleration(a);
	   else if(cs.y[0]-c.y[0] < Dx){
		 c.y[1]=cs.y[1];
		 c.setAcceleration(0.);
	   }else if(cs.acceleration<=0.){
		aNeeded=(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/(cs.y[0]-c.y[0]);
		c.setAcceleration(aNeeded);
	   }
	  }
	 }
	 if( (cs!=null)   && (cs.y[0]-c.y[0] < Dx) ){
	  c.y[1]=0.;
	 }
   }

	// advanced one time step
	//drawCar(c,L.X,sign,true);
	c.advanced(dt);
	drawCar(c,L.X,sign,false);
	cs=c;
   }
   if((int)c.y[0]>ymin+Dx){
	v2.addElement(new car(ymin,0.,a2));
	drawCar(c,L.X,sign,false);
   }
  }
}
void drawVelocity(Graphics g0){
  int size=2,size2=4;
  int xoffset=-w2-size,yoffset=y0-(int)roadWidth-size+h;
  g0.setColor(Color.blue);
  for(Enumeration e=v.elements();e.hasMoreElements();){
   c=(car)e.nextElement();
   g0.fillOval((int)c.y[0]+xoffset,yoffset-(int)(2.*c.y[1]),
	size2,size2);
  }
}
}

class car extends rk4 {
double acceleration=10.;
static double vmax=30.,vmin=0.,vMove=3.;
double xmax=100.;
int lightID;
boolean front=false;

car(double xi,double vi,double ai){
  init(2,true);
  y[0]=xi;
  y[1]=vi;
  acceleration=ai;
  lightID=0;
}

void setAcceleration(double ai){
  acceleration=ai;
}
boolean isFront(){return front;}
void setFront(boolean f){
  front=f;
}
void advanced(double dt){
  nextmove(dt);
  if(y[1]<vmin){
   acceleration=0.;
   y[1]=0.;
  }else if(y[1]>vmax){
   acceleration=0.;
   y[1]=vmax;
  }
}
public void derivs (double t,double y[],double dydx[]){
  dydx[0]=y[1]; // V_theta
  dydx[1]=acceleration; // alpha=-K theta
}
}

// RK4
abstract class rk4 {
int n;
public double dydx[];
public double y[],yout[];
public void init(int dim,boolean self){
  n=dim;
  dydx=new double[n];
  yout=new double[n];
  if(self)y=yout;
   else y=new double[n];
}

  public abstract void derivs(double x,double y1[],double dydx[]);
/*								
public void next(double x,double h){ // t & dt
  core(x,h);
}
public double[]  next(double h){ // dt
  core(0.,h);
  return yout;
}*/
public void nextmove(double h,double[] yin){
  y=yin;
  core(0.,h);
}
public void nextmove(double h){
  core(0.,h);
}
private void core(double x, double h){
/* Runge-Kutta forth-order Method */
  int i;
  double xh,hh,h6;
  double dym[]=new double[n];
  double dyt[]=new double[n];
  double yt[]=new double[n];
  hh=h*0.5;
  h6=h/6.0;
  xh=x+hh;
  derivs(xh,y,dydx);
  for (i=0;i<n;i++) yt=y+hh*dydx;
  derivs(xh,yt,dyt);
  for (i=0;i<n;i++) yt=y+hh*dyt;
  derivs(xh,yt,dym);
  for (i=0;i<n;i++) {
   yt=y+h*dym;
   dym += dyt;
  }
  derivs(x+h,yt,dyt);
  for (i=0;i<n;i++)
   yout=y+h6*(dydx+dyt+2.0*dym);
}
}

لكي تكوني في الصورة قمت بجعل الفئة الموروثة JApplet

قمت بتجريبه على الAppletViewer واشتغل

تستطيعي تجريبه عن طريق الوسم applet في لغة html

تحياتي

اهلين اخي ,,

احنا مطالبين انه يشتغل على ال java creator

و جربت نفس الشي ما يشتغل :(

معليش يا أختي لما تعملي applet

وما تكوني عارفة وين بيشتغل

فأنتي في مشكلة

على العموم applet معمول خصيصاً للإنترنت

فلا تتوقعي منه أن يشتغل كانه برنامج سطح مكتب

تحياتي