when do you need constructors java code example

Example 1: how to create a constructor in java

class Other{
    public Other(String message){
        System.out.println(message);
    }
}

class scratch{
    public static void main(String[] args) {
        Other method = new Other("Hey");
        //prints Hey to the console
    }
}

Example 2: where to use constructors in framework java

In my framework Our BasePage class 
have a constructor  which takes a 
WebDriver object to initialize
a WebDriverWait object. The constructor will
also be responsible to initialize 
WebElements via PageFactory.