How can I make a code in p5.js mode work in Java mode?

asdf

I have this code which works in Processing p5.js mode but not in Java mode. Is there a way to make the code work in Java mode as well? If so, what should i change? I am a beginner in coding and would appreciate your help. Thank you.

var rockets = []; 
var sparkles = [];
var moving = true;
var gravity = 0.4;

function setup() {
    // put setup code here

    createCanvas(windowWidth, windowHeight);
    background(0);
    strokeWeight(1);

    colorMode(HSB);

    var thisRocket = new rocket();
    rockets.push(thisRocket);
}

function draw() {
    // put drawing code here
    translate(width / 2, height);
    background('rgba(0,0,0, 0.1)');
    for (var i = rockets.length - 1; i >= 0; i--) 
    {
        if(rockets[i].type == "Exploded")
            rockets.splice(i,1);
        else
            rockets[i].draw();
    }   

    for (var i = sparkles.length - 1; i >= 0; i--) 
    {
        if(sparkles[i].position.y > 0 || sparkles[i].brt <= 0)
            sparkles.splice(i,1);
        else
            sparkles[i].draw();
    }   

    if (int(random(0, 12)) == 0)
    {
        var thisRocket = new rocket();
        rockets.push(thisRocket);
    }
}

function rocket(position, speed, type, sparkler, afterblow)
{
//  stroke(255);

    if (position == undefined)
        this.position = createVector(int(random(-width / 2, width / 2)), 0);
    else 
        this.position = position.copy();

    if (speed == undefined)
        this.speed = createVector(random(-1,1), -random(10,22));
    else
        this.speed = speed.copy();

    if (afterblow == undefined)
        this.afterblow = -1;
    else
        this.afterblow = afterblow;

    if (sparkler == undefined)
        this.sparkler = round(random(0,1)) == 0;
    else
        this.sparkler = sparkler;

    this.fuse = random(-1,1);
    this.hue = round(random(0,360));

    this.type = type;
    if(type == undefined)
    {
        typeIndex = int(random (0,9));
        switch (typeIndex)
        {
            case 0:
                this.type = "simple";
                break;
            case 1:
                this.type = "blinker";
                break;
            case 2:
                this.type = "directed";
                break;
            case 3:
                this.type = "burster";
                break;
            case 4:
                this.type = "double";
                break;
            case 5:
                this.type = "mega";
                break;
            case 6:
                this.type = "sparkleBlinker";
                break;
            case 7:
                this.type = "writer";
                break;
            case 8:
                this.type = "swirler";
                break;
        }
    }

    this.draw = function()
    {
        stroke(255);
        if(this.fuse < this.speed.y || this.afterblow >= 0)
            this.explode();

        if (this.sparkler) 
        {
            sparkleDir = random(0, TWO_PI);
            sparkleVel = random(0,1);
            sparkleSpd = createVector(sparkleVel * cos(sparkleDir), sparkleVel * sin(sparkleDir))
            thisSparkle = new sparkle(createVector(this.position.x+sparkleSpd.x, this.position.y+sparkleSpd.y), sparkleSpd.copy(),random(50,75), round(random(20,40)), round(random(0,30)));
            sparkles.push(thisSparkle);
        }
        stroke(this.hue+round(random(-10,+10)), random(0,20), 90);

        point(this.position.x,this.position.y);

        this.position.add(this.speed);
        this.speed.y = this.speed.y + gravity;
    }

    this.explode = function()
    {
        switch (this.type)
        {
            case "blinker":
            {
                if (this.afterblow == -1)
                 this.afterblow = round(random(3,8));

                if(this.afterblow-- > 0)
                {
                    noStroke()
                    thisSize = random (40,60)
                    fill(this.hue+round(random(-10,+10)), random(0,20), 90);
                    ellipse(this.position.x + random(-30,30) ,this.position.y + random(-30,30) ,thisSize,thisSize);
                }
                else
                    this.type = "Exploded";
            }
            break;
        case "directed":
            {
                var dir = random(0, TWO_PI);
                for (var i = 0; i < 50; i++) 
                {
                    sparkleDir = dir+random(0, PI/1.5);
                    sparkleVel = random(3,5);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(3,8), this.hue+round(random(-10,+10)), round(random(0,40)));
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "burster":
            {
                for (var i = 0; i < 60; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,3) + random(0,3);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(3,8), this.hue+round(random(-10,+10)), round(random(0,40)), "sparkler");
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "double":
            {
                for (var i = 0; i < 90; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(3,5);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(2,4), this.hue+round(random(-10,+10)), round(random(0,40)));
                    sparkles.push(thisSparkle);
                }
                for (var i = 0; i < 10; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,.5);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(2,4), this.hue+round(random(-10,+10)), round(random(0,40)));
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "mega":
            {
                for (var i = 0; i < 1000; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,4)+random(0,4);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(3,8), this.hue+round(random(-10,+10)), round(random(0,40)));
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "sparkleBlinker":
            {
                for (var i = 0; i < 100; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,2)+random(0,3);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(1,3), this.hue+round(random(-10,+10)), round(random(0,40)),"blinker");
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "writer":
            {
                for (var i = 0; i < 100; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,2)+random(0,3);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(1,3), this.hue+round(random(-10,+10)), round(random(0,40)),"writer");
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        case "swirler":
            {
                for (var i = 0; i < 60; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,3) + random(0,3);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(3,8), this.hue+round(random(-10,+10)), round(random(0,40)), "swirler");
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
            break;
        default:
            {
                for (var i = 0; i < 100; i++) 
                {
                    sparkleDir = random(0, TWO_PI);
                    sparkleVel = random(0,5);
                    sparkleSpd = createVector(this.speed.x + sparkleVel * cos(sparkleDir), this.speed.y + sparkleVel * sin(sparkleDir))
                    thisSparkle = new sparkle(this.position.copy(), sparkleSpd.copy(), random(1,3), this.hue+round(random(-10,+10)), 0);
                    sparkles.push(thisSparkle);
                }
                this.type = "Exploded";
            }
        }
    }
}

function sparkle(position, speed, fade, hue, sat, type)
{
    this.position = position.copy();
    this.speed = speed.copy(); 
    this.fade = (fade == undefined ? 5 : fade);
    this.hue = (hue == undefined ? 360 : hue);
    this.sat = (sat == undefined ? 0 : sat);
    this.type = (type == undefined ? "default" : type);

    this.brt = 255;

    this.burntime=0;

    this.draw = function()
    {
        stroke(this.hue, this.sat, this.brt);
        newPositionX = this.position.x + log(this.burntime) * 8 * this.speed.x;
        newPositionY = this.position.y + log(this.burntime) * 8 * this.speed.y + this.burntime * gravity;

        point(newPositionX, newPositionY);

        if (this.type == "writer" && this.burntime > 1)
        {
            line(newPositionX, newPositionY, this.position.x + log(this.burntime-2) * 8 * this.speed.x, this.position.y + log(this.burntime-2) * 8 * this.speed.y + this.burntime * gravity);
        }

        if(this.type == "swirler")
        {
            sparkleDir = this.burntime/2 % TWO_PI;
            sparkleVel = random(0,1);
            sparkleSpd = createVector(sparkleVel * cos(sparkleDir), sparkleVel * sin(sparkleDir))
            thisSparkle = new sparkle(createVector(newPositionX+sparkleSpd.x, newPositionY+sparkleSpd.y), sparkleSpd.copy(),random(50,75), round(random(20,40)), round(random(0,30)));
            sparkles.push(thisSparkle);
        }

        if(this.type == "sparkler")
        {
            sparkleDir = random(0, TWO_PI);
            sparkleVel = random(0,1);
            sparkleSpd = createVector(sparkleVel * cos(sparkleDir), sparkleVel * sin(sparkleDir))
            thisSparkle = new sparkle(createVector(newPositionX+sparkleSpd.x, newPositionY+sparkleSpd.y), sparkleSpd.copy(),random(50,75), round(random(20,40)), round(random(0,30)));
            sparkles.push(thisSparkle);
        }

        this.brt = this.brt - fade;

        if(this.type == "blinker" && this.burntime > random(10,15))
        {
            if(int(random(0,15)) == 0)
            {
                noStroke()
                thisSize = random (20,30)
                fill(this.hue+round(random(-10,+10)), random(0,10), 100);
                ellipse(newPositionX, newPositionY, thisSize, thisSize);
            }
            this.brt = 0;
        }

        this.burntime++;

    }
}

function touchStarted() 
{
    if(moving)
    {
        moving = false; 
        strokeWeight(1);
        fill(255);
        rect(width/2-30, -height+20, 10, 30);
        rect(width/2-50, -height+20, 10, 30);
        noLoop();
        }
        else
        { 
            moving = true;
        loop();
    } 
    // prevent default
    return false;
}

GoToLoop

https://GitHub.com/processing/p5.js/wiki/Processing-transition

https://www.Reddit.com/r/processing/comments/7dqqvh/openprocessing_converting_code_written_in_java_to/

asdf

Thank you!

var rockets = []; 
var sparkles = [];
var moving = true;
var gravity = 0.4;

I've changed the above four lines to

float rockets = []; 
float sparkles = [];
float moving = true;
float gravity = 0.4;

but i get an error message. Any advice??

GoToLoop

Java doesn't have such simple way to instantiate arrays like []. :(
Read more about how to on these 2 links: ~O)

1. https://Processing.org/reference/Array.html
2. https://Docs.Oracle.com/javase/tutorial/java/nutsandbolts/arrays.html

BtW, don't forget to take a look at my cross-flavor sketches at the Reddit link below: L-)
https://www.Reddit.com/r/processing/comments/7dqqvh/openprocessing_converting_code_written_in_java_to/dq0ecac/

asdf

Thank you for the answer. Could you tell me how can I rewrite those four lines so that they work in java mode?

GoToLoop

There's no ready answer for it! In Java, all variables have a datatype in which we've gotta specify when declaring them. #:-S

Also, Java arrays have a fixed length. If you need to change its length later, you're better off picking another container type. For example, the ArrayList: >-)
https://Processing.org/reference/ArrayList.html

Again, pay attention on the diffs. between the Java & JS versions of the sketch links I've posted on Reddit. O:-)