Run cross browser tests using TestNG - Chrome | IE | Safari | Opera | Firefox

1| Download Chromedriver 2.9 and IEDriverserver

2| Extract the zipped folders and mention proper location in code [highlighted below].
3| Edit testng.xml as shown below,

testng.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Suite" verbose="3" parallel="tests" thread-count="5">
  
<test name="Test on Firefox">
  <parameter name="browser" value="Firefox"/>
  <classes>      
    <class name="package.classname"/>       
  </classes>
</test>  
<test name="Test on Chrome">
  <parameter name="browser" value="Chrome"/>
  <classes>      
    <class name="package.classname"/>       
  </classes>
</test>
<test name="Test on InternetExplorer">
  <parameter name="browser" value="InternetExplorer"/>
  <classes>      
    <class name="package.classname"/>       
  </classes>
</test>
<test name="Test on Safari">
  <parameter name="browser" value="Safari"/>
  <classes>      
    <class name="package.classname"/>       
  </classes>
</test>
</test>
<test name="Test on Opera">
  <parameter name="browser" value="Opera"/>
  <classes>      
    <class name="package.classname"/>       
  </classes>
</test>
</suite> <!-- Suite -->

Snippet

@BeforeTest

@Parameters({"browser"})

  public void setUp(String browser) throws MalformedURLException

  {          

 if (browser.equalsIgnoreCase("Firefox")) 

 {

 System.out.println("Running Firefox");

  driver = new FirefoxDriver();

  baseUrl = "http://xyz.com";

 } 

 

 else if (browser.equalsIgnoreCase("chrome")) 

 {

 System.out.println("Running Chrome");

 System.setProperty("webdriver.chrome.driver","C:\\chromedriver.exe");  

 driver = new ChromeDriver();

 baseUrl = "http://xyz.com";

 } 

 

 else if (browser.equalsIgnoreCase("InternetExplorer")) 

 {

 System.out.println("Running Internet Explorer");

 System.setProperty("webdriver.ie.driver","C:\\IEDriverServer.exe");

    DesiredCapabilities dc = DesiredCapabilities.internetExplorer();

dc.setCapability(InternetExplorerDriver.INTRODUCE_FLAKINESS_BY_IGNORING_SECURITY_DOMAINS, true);  //If IE fail to work, please remove this and remove enable protected mode for all the 4 zones from Internet options

 driver = new InternetExplorerDriver(dc);

 baseUrl = "http://xyz.com";

 } 

   else if (browser.equalsIgnoreCase("safari")) 

  {

  System.out.println("Running Safari");

  driver = new SafariDriver();

  baseUrl = "http://xyz.com";

  } 

   else if (browser.equalsIgnoreCase("opera")) 

  {

  System.out.println("Running Opera");
    // driver = new OperaDriver();       --Use this if the location is set properly | see note #2 below--
    DesiredCapabilities capabilities = new DesiredCapabilities();
    capabilities.setCapability("opera.binary", "C://Program Files (x86)//Opera//opera.exe");
    capabilities.setCapability("opera.log.level", "CONFIG");
    driver = new OperaDriver(capabilities);

  baseUrl = "http://xyz.com";

  } 

}


Note:- 
1| There are drawbacks in SafariDriver
Here, I have used,
Safari | 5.0.3 (7533.19.4)
Selenium | 2.35
OS | Windows Vista
# SafariDriver won't work properly in Windows 7
# SafariDriver does not support interacting with modal dialogs
# Cannot navigate forwards or backwards in browser history and more...

2| OperaDriver doesn't support Opera browser versions 13 and above
# Make sure the location of opera.exe under, %PROGRAMFILES%\Opera\opera.exe; If not, then try to locate the execution file using Capabilities