Dynamic Typed: Redundant imports in Java

When you are creating a class in Java you can import packages with the "import" clause, for example:

import java.util.Random;

public class Blogger {
   public static void main(String[] args) {
       Random random = new Random();
       System.out.println(random.nextInt(9));
   } 
}

In this case we are importing the class "Random.java" from the package util.

But java allows us to import multiple packages, even we can have multiple redundant import declarations in a class, as follows:

import java.util.Random;
import java.util.Random; //Redundant import clause

public class Blogger {
   public static void main(String[] args) {
       Random random = new Random();
       System.out.println(random.nextInt(9));
   } 
}

This class will compile without any problem, and will print a random number between 0 and 9.

Another type of redundant import is when you import a class that is in the same package, for example, suppose that you have a class "Comment.java" and "Blogger.java" in the package "mysite". it is not necessary to have the clause "import mysite.Comment" in the class "Blogger.java", as follows:

package mysite;

import java.util.Date;

import mysite.Comment; //Redundant import clause

public class Blogger {
    public static void main(String[] args) {
        Comment mycomment = new Comment("My comment for today", new Date());
        System.out.println(mycomment.getCommnet());
    }
}

package mysite;

import java.util.Date;

public class Comment {
    private String comment;
    private Date date;

    public Comment(String comment, Date date){
        this.comment = comment;
        this.date = date;
    }

    public String getCommnet(){
        return this.comment;
    }

    public Date getDate(){
        return this.date;
    }
}

this type of import as mentioned before it is not necessary since Java will automatically look for the classes that you are using in the same package.

So be careful with the way you import classes in java, even though many modern IDE can help you to automatically import package and classes, it is good to know and understand this types of redundant imports because it can be a great help if you are facing an interview or solving a certification exam.

Dynamic Typed

viernes, 17 de julio de 2020

Redundant imports in Java

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