The Mystery of life

//Vehicle.java

class Vehicle1{
private double load, maxLoad;
public Vehicle1 (double max){
this.maxLoad = max;
}
public double getLoad(){
return this.load;
}
public double getMaxLoad(){
return this.maxLoad;
}
public boolean addBox(double weight){
double temp = 0.0D;
temp = this.load + weight;
if(temp <= maxLoad){
this.load = this.load + weight;
return true;
}
else{
return false;
}
}
}

//MainVehicle.java

class TestVehicle1{
public static void main(String[] args){
System.out.println("Creating a vehicle with a 10,000 kg maximum load.");
Vehicle1 vehicle = new Vehicle1(10000);
System.out.println("Add box #1 (500kg) : " + vehicle.addBox(500));
System.out.println("Add box #2 (250kg) : " + vehicle.addBox(250));
System.out.println("Add box #3 (5000kg) : " + vehicle.addBox(5000));
System.out.println("Add box #4 (4000kg) : " + vehicle.addBox(4000));
System.out.println("Add box #5 (300kg) : " + vehicle.addBox(300));
System.out.println("Vehicle load is " +vehicle.getLoad() + "kg");
}
}

output :

Add box #1 (500kg) : true
Add box #2 (250kg) : true
Add box #3 (5000kg) : true
Add box #4 (4000kg) : true
Add box #5 (300kg) : false
Vehicle load is 9750.0kg