Development Assistance Custom FallingSand disappears.

Hello,

I have been trying to make a plugin that spawns a custom fallingsand entity, which works fine, more or less. The only problem is that the custom fallingsand disappears after about half a second. What do I do to make a proper fallingsand entity that doesn't disappear?

This is my main class:

Main class (open) Main class (close)

Code:java

package p;
 
import net.minecraft.server.v1_7_R1.World;
 
import org.bukkit.Location;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.craftbukkit.v1_7_R1.CraftWorld;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;
 
public class TestFire extends JavaPlugin{
    public void onEnable() {}
 
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (cmd.getName().equalsIgnoreCase("fire")) {
            Player player = (Player) sender;
            World world = ((CraftWorld) player.getWorld()).getHandle();
            Location loc = player.getEyeLocation();
            loc.add(loc.getDirection());
            CustomFire myFire = new CustomFire(loc, loc.getDirection());
            world.addEntity(myFire);
        }
        return false;
    }
 
    public void onDisable() {}
}

And this is my custom fallingsand entity:

Custom entity (open) Custom entity (close)

Code:java

package p;
 
import org.bukkit.Location;
import org.bukkit.craftbukkit.v1_7_R1.CraftWorld;
import org.bukkit.util.Vector;
 
import net.minecraft.server.v1_7_R1.Blocks;
import net.minecraft.server.v1_7_R1.EntityFallingBlock;
 
public class CustomFire extends EntityFallingBlock {
    public CustomFire(Location loc, Vector vec) {
        super(((CraftWorld) loc.getWorld()).getHandle(), loc.getX(), loc.getY(), loc.getZ(), Blocks.FIRE);
        this.motX = vec.getX();
        this.motY = vec.getY();
        this.motZ = vec.getZ();
        this.ticksLived = 20;
    }
}

 

Register your class!

 

Thank you for the quick reply. @thepluginbros
Could anyone point me to a source which explains how to register entities?
I have been trying to use

Show Spoiler Hide Spoiler

Code:java

try {
    Method a = EntityTypes.class.getDeclaredMethod("a", Class.class, String.class, int.class);
    a.setAccessible(true); 
    a.invoke(a, CustomFire.class, "FallingSand", 21);
} catch (Exception e) {
    e.printStackTrace();
}

but it gives me an InvocationTargetException.