CODEWITHSUNDEEP
javanullpointerexceptionpackage
prog
prog

Reputation: 150

equals() gives me null pointer exception

This is my equal method:

public boolean equals(Car other)
{
if (other == null)
{
    return false;
}

if (this.genre.equals(other.genre))
{

    if (this.price == other.price && this.height == other.height && this.name == other.name && this.door = other.door)
    {
        return true;
    }
    else
    {
        return false;
    }

}
else
{
    return false;
}

}

For some reason, this line gives me a null pointer exception: this.genre.equals(other.genre)

genre is a variable from another package;

All variables were declared in the class Car. The program compiles fine.

This is the constructor of Car:

    public Car(double price, float height, String genre, String name, int door)
{
    super(price, height, genre);
            this.name = name;
            this.door = door;

}

Why am I getting a null pointer exception?

Upvotes: 0

Views: 992

Answers (3)

Ruan Mendes
Ruan Mendes

Reputation: 92274

Because this.genre is null?

if (this.genre != null && this.genre.equals(other.genre))

Upvotes: 2

Subhrajyoti Majumder
Subhrajyoti Majumder

Reputation: 41200

I suspect you are equaling with null String genre in Car Object which cause NullPointerExcaption.

if (this.genre!=null && this.genre.equals(other.genre)){...}

One more thing -

...
if(...this.door = other.door){
           ^^^^

It should be ==.

Upvotes: 0

DwB
DwB

Reputation: 38300

Start using a library that correctly handles nulls when performing string comparisons.

Start using apache commons lang. Here is the StringUtils JavaDoc page

Upvotes: 0

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