Java: Clean way of avoiding NullPointerException in equals checks

Question

I have an address object that I want to create an equals method for. I could have made this quite simple by doing something like the following (shortened a bit):

Answer 1

You could do the following:

public boolean equals(Object obj) 
{
    if (this == obj) {
        return true;
    }

    if (obj == null) {
        return false;
    }

    if (getClass() != obj.getClass()) {
        return false;
    }

    Address other = (Address) obj;

    return equals(this.getStreet(),other.getStreet())
        && equals(this.getStreetNumber(), other.getStreetNumber())
        && equals(this.getStreetLetter(), other.getStreetLetter())
        && equals(this.getTown(), other.getTown());
}

private boolean equals(Object control, Object test) {
    if(null == control) {
        return null == test;
    }
    return control.equals(test);
}

Java 7 introduced built-in support for this use case with the java.util.Objects class see:

• java.utils.Objects.equals(Object, Object)
• java.utils.Objects.deepEquals(Object, Object)