How to use Implicit wait and Explicit wait in Selenium Web driver -Java

A brief into about implicit wait and explicit wait and when to use what.

Implicit Wait:-

Implicit waits are used when we need to wait for a certain element to appear or visible on the screen before we can proceed to next action.Once an Implicit wait is set it is set for life time of the web driver.

ImplicitWaitDemo.java

package com.example;

import java.util.Calendar;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.Test;

public class ImplicitWaitDemo {
 
 @Test
 public void implicitWaitDemo () throws InterruptedException{
  WebDriver driver=new FirefoxDriver();
  
  //Print the current time
  System.out.println(Calendar.getInstance().getTime());
  //Implicitily wait for 10 seconds
  driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
  driver.get("http://www.learn-selenium.net/");
  //print current time
  System.out.println(Calendar.getInstance().getTime());
  // Maximize the Browser Window.
  driver.manage().window().maximize(); 
  //Close the browser
  driver.close();
 }

}

Explicit Wait:-

Explicit waits are used when we need to wait for a certain condition to happen like a button click or an alert open.This is like waiting for a condition to happen this can be acheived using webdriver wait.Below is a simple example .

ExplicitWaitDemo.java


package com.example;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;
import org.testng.annotations.Test;

public class ExplicitWaitDemo {
 
 @Test
 public void explicitWaitDeom() throws InterruptedException{
  WebDriver driver=new FirefoxDriver();
  driver.get("http://www.learn-selenium.net/");

  //Explicitily  wait for 10 seconds
  WebElement myelement = (new WebDriverWait(driver, 10)).until(ExpectedConditions.presenceOfElementLocated(By.xpath("/html/body/nav/div/div[1]/a[2]")));
  
  System.out.println(myelement.getText().toString());
 
  // Maximize the Browser Window.
  driver.manage().window().maximize(); 
  //Close the browser
  driver.close();
 }

}

Note/Warning: Do not use explicit and implicit wait together as the results would be unpredictable.Suppose you use implicit wait of 10 seconds and then explicit wait of 20 seconds you may get an exception any time after 10 Seconds.