Trying to increase health bar when particle system drops hits the PImage. Not sure how to do it :/

The piece of code I am trying to get working is commented out in draw().

import processing.serial.*;

import cc.arduino.*;

import static javax.swing.JOptionPane.*;
import javax.swing.JPasswordField;


final StringDict accounts = new StringDict(
  new String[] {
  "john", "tony", "amy"
  }
  , new String[] {
    "ilikedogs", "husky", "pepsi"
  }
  );

final JPasswordField pwd = new JPasswordField();

{
  println(accounts);
}

PImage startGameBackground;
PImage kitchen;
PImage dog;
float dogx=800, dogy=600;
HealthBar hb0 = new HealthBar();
boolean isWashed=false;

PImage achievment2;

int stage =1;
Serial port;

Fountain f = new Fountain();
//Ball b = new Ball(x,y,d,xs,ys);
ArrayList<Ball>ballList;

void setup() {
  size(1800, 900);
  String comPort = "COM3";

  stage =1;
  port = new Serial(this, comPort, 9600);

  f.fountainSetup();
  startGameBackground = loadImage("startGameBackground.png");
  kitchen = loadImage("kitchen.png");
  dog = loadImage("washDog.png");
  startGameBackground.resize(1800, 900);
  kitchen.resize(1800, 900);
  achievment2 = loadImage("achievment2.png");
}

void draw() {

  if (stage ==1) {

    background(startGameBackground);

    if (frameCount == 10)  surface.setVisible(true);


    String user = askUser();

    if (user == null)           confirmQuit();
    else if (!"".equals(user))  askPass(user);

  } else if (stage ==2) {

    background(kitchen);
    image(dog, dogx, dogy);
    hb0.draw();
    isWashed =true;

    f.fountainDraw();

    //if (hb0.value <100) {
    //   //delay(1000);
    //   hb0.value += .5;
    // }

    // else if(hb0.value == hb0.max){
    //   println("Here is the achievment");
    //   image(achievment2, 500,100);
  }
}
}

String askUser() {
  String id = showInputDialog("Please enter user:");

  if (id == null)
    showMessageDialog(null, "You've canceled login operation!"
      , "Alert", ERROR_MESSAGE);

  else if ("".equals(id))
    showMessageDialog(null, "Empty user input!"
      , "Alert", ERROR_MESSAGE);

  else if (!accounts.hasKey(id = id.toLowerCase()))
    showMessageDialog(null, "Unknown \"" + id + "\" user!" + (id = "")
      , "Alert", ERROR_MESSAGE);

  return id;
}

boolean askPass(String id) {
  boolean isLogged = false;
  pwd.setText("");

  int action = showConfirmDialog(null, pwd
    , "Now enter password:", OK_CANCEL_OPTION);

  if (action != OK_OPTION) {
    showMessageDialog(null, "Password input canceled!"
      , "Alert", ERROR_MESSAGE);

    return false;
  }

  String phrase = pwd.getText();
  //String phrase = new String(pwd.getPassword());

  if ("".equals(phrase))
    showMessageDialog(null, "Empty password input!"
      , "Alert", ERROR_MESSAGE);

  else if (accounts.get(id).equals(phrase)) {
    showMessageDialog(null, "Welcome \"" + id + "\"!\nYou're logged in!"
      , "Info", INFORMATION_MESSAGE);

    isLogged = true;
    stage=2;
  } else
    showMessageDialog(null, "Password \"" + phrase + "\" mismatch!"
      , "Alert", ERROR_MESSAGE);

  return isLogged;
}

void confirmQuit() {
  if (showConfirmDialog(null, "Wanna quit then?", "Exit"
    , OK_CANCEL_OPTION) == OK_OPTION)  exit();
}


public class Ball {

  float x, y, xSpeed, ySpeed, diameter;
  int dropColour;
  boolean isAlive;
  int stepsAlive;
  HealthBar hb0 = new HealthBar();

  public Ball(float x, float y, float d, float xs, float ys) {
    this.x=x;
    this.y =y;
    this.diameter =d;
    xSpeed =xs;
    ySpeed =ys;
    isAlive = true;
    int stepsAlive =0 ;
  }

  public void move() {
    stepsAlive++;
    x = x + xSpeed;
    y = y + ySpeed;

    if (x >=800) {

      xSpeed = -xSpeed;
    }

    if (x <=950) {

      xSpeed = -xSpeed;
    }

    ySpeed = ySpeed +0.1F;

    if (y  > 800) {
      ySpeed = -ySpeed;
    }
  }

  public void isDead() {

    if (stepsAlive >= 400) {
      isAlive = false;
    }

    if (dist(x, y, dogx, dogy) <100  ) {

      isAlive = false;
    }

    if (y  > 800) {
      isAlive =false;
    }
  }
}


import ddf.minim.*;

public class Fountain {
  ArrayList<Ball> ballList;
  AudioPlayer player;
  Minim minim;
  HealthBar hb0 = new HealthBar();

  void fountainSetup() {
    //size(600,600);
    ballList = new ArrayList<Ball>();
    //minim = new Minim(this);
  }

  public void fountainDraw() {
    //background(255,255,255);

    // if (mousePressed){
    if (mousePressed ==true) {
      float xSpeed = (float)(-3 + Math.random()*6);
      Ball b = new Ball(880, 400, 20, xSpeed, -2);

      b.dropColour = color(204, 255, 255);

      ballList.add(b);
    }

    for (int i =0; i <ballList.size(); i++) {
      Ball b2 = ballList.get(i);

      fill(b2.dropColour);
      ellipse(b2.x, b2.y, b2.diameter, b2.diameter);
      b2.move();
      //println("working");

      b2.isDead();

      if (b2.isAlive == false)
        ballList.remove(b2);

          println(dogy + ""+ "This thing is broke");
        }
      }
    }

class HealthBar {
  float value, max, x, y, w, h;
  color backing, bar;
  HealthBar(){
    value = 0;
    max = 100;
    x = 800;
    y = 60;
    w = 200;
    h = 30;
    backing = color(255,0,0);
    bar = color(0,255,0);
  }
  void draw(){
    fill(backing);
    stroke(0);
    rect(x,y,w,h);
    fill(bar);
    rect(x,y,map(value,0,max,0,w),h);
  }
}