Loose Coupling and Tight Coupling in Java with example

Loose Coupling and Tight Coupling in Java with example



Hello Friends,

This article will describe the concept of tight and loose coupling in java.

Coupling :- Degree of dependency of Class A on Class B.
How often do changes in one class force changes in another class.


Tight Coupling :-
Two classes often change together If class A knows more than it should about the way in which class B was implemented, then A and B are tightly coupled.


Loose Coupling :-
Reducing the dependencies of a class that uses the different classes directly.
If the only knowledge that class A has about class B, is what class B has exposed through its interface, then class A and class B are said to be loosely coupled.


Example of Tight coupling

class A1
{
A1(int x , int y)
{
System.out.println("sum is " + (x+y));
}
void sam()
{
System.out.println("i am method of class A");
}
}
class B extends A1
{
B(int x, int y)
//have to add this constructor other wise while creating the object , compile time error will appear. {
super(x, y);
}
void sam()
{
System.out.println("i am method of class B");
}
}
public class Coupling
{
public static void main(String args[])
{
B obj = new B(7, 8);
obj.sam();
}
}

Example of loose coupling

interface mycoup
{
void sample();
}
class A1 implements mycoup
{
A1(int x , int y)
{
System.out.println("sum is " + (x+y));
}
@Override
public void sample()
{
System.out.println("i am method of class A");
}
}
class B implements mycoup
{
public void sample()
{
System.out.println("i am method of class B");
}
}
public class Coupling
{
public static void main(String args[])
{
B obj = new B();
obj.sample();
A1 obj1 = new A1(3, 7);
obj1.sample();
}
}

Output:-
i am method of class B
sum is 10
i am method of class A

Upload Operation in Selenium testing the post

How to upload the file using selenium

Click Here to navigate on practice page

Hello Friends, In this tutorial we will learn how to perform upload operation in selenium.
We can perform the upload operation in selenium by two ways :
1). First by SendKeys() method.
2). Second by using the robot class.
First Method :
Precondition : Element should be input and type should be "file", as shown below :

Now we just need to locate the element and just use the method sendKeys() and in sendKeys() method we will pass the path of that file.
Syntax :-
driver.findElement(By.xpath("path of element")).sendKeys("path on file");

Here is sample code :-

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;

public class Uploadfile
{
WebDriver driver;
@BeforeTest
public void g() throws InterruptedException
{
System.setProperty("webdriver.chrome.driver", "C:\\Users\\cchauhan\\Downloads\\chromedriver_win32\\chromedriver.exe");
driver = new ChromeDriver();
/*FirefoxOptions foptions = new FirefoxOptions();
foptions.setCapability("marionette", false);
driver = new FirefoxDriver(foptions);*/
driver.manage().window().maximize();
driver.navigate().to("http://www.way2testing.com/p/this-webpage-is-designed-for-selenium.html");
Thread.sleep(3000);
}
@Test
public void h()
{
//Remember element should be input and type should be "file"
driver.findElement(By.xpath(".//*[@id='post-body-2064404811754288590']/form[1]/input[1]")).sendKeys("C:\\Users\\cchauhan\\Desktop\\wallpaper.png");
}
}

Second Method : By using Robot Class:-
What is Robot class ?
"Basically robot class will simulate the Keyboard and mouse actions."
Steps :-
1). First Copy the file path.
2).Paste the file path in popup window
3).Press Enter button.

by robot class we can perform CTRL + C operation by below methods as :-
StringSelection ss = new StringSelection("C:\\Users\\cchauhan\\Desktop\\wallpaper.png");
Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, null);

by robot class we can perform CTRL + V operation as below :-
robot.keyPress(KeyEvent.VK_CONTROL);
robot.keyPress(KeyEvent.VK_V);
robot.keyRelease(KeyEvent.VK_CONTROL);
robot.keyRelease(KeyEvent.VK_V);



by robot class we can press enter key as below :-
robot.keyPress(KeyEvent.VK_ENTER);
robot.keyRelease(KeyEvent.VK_ENTER);

Here is sample code :-

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyEvent;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;
public class Uploadfile
{
WebDriver driver;
@BeforeTest
public void g() throws InterruptedException
{
System.setProperty("webdriver.chrome.driver", "C:\\Users\\cchauhan\\Downloads\\chromedriver_win32\\chromedriver.exe");
driver = new ChromeDriver();
/*FirefoxOptions foptions = new FirefoxOptions();
foptions.setCapability("marionette", false);
driver = new FirefoxDriver(foptions);*/
driver.manage().window().maximize();
driver.navigate().to("http://www.way2testing.com/p/this-webpage-is-designed-for-selenium.html");
Thread.sleep(3000);
}
@Test
public void h() throws AWTException
{
driver.findElement(By.xpath(".//*[@id='post-body-2064404811754288590']/form[1]/input[1]")).click();
Robot robot = new Robot();
robot.setAutoDelay(2000);
StringSelection ss = new StringSelection("C:\\Users\\cchauhan\\Desktop\\wallpaper.png");
Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, null);
robot.setAutoDelay(2000);
robot.keyPress(KeyEvent.VK_CONTROL);
robot.keyPress(KeyEvent.VK_V);
robot.keyRelease(KeyEvent.VK_CONTROL);
robot.keyRelease(KeyEvent.VK_V);
robot.keyPress(KeyEvent.VK_ENTER);
robot.keyRelease(KeyEvent.VK_ENTER);
}
}