Maybe you met these exceptions sometimes:

1. Chrome Driver

The path to the driver executable must be set by the webdriver.chrome.driver system property; for more information, see https://github.com/SeleniumHQ/selenium/wiki/ChromeDriver. The latest version can be downloaded from http://chromedriver.storage.googleapis.com/index.html

2. Firefox Driver

The path to the driver executable must be set by the webdriver.gecko.driver system property; for more information, see https://github.com/mozilla/geckodriver. The latest version can be downloaded from https://github.com/mozilla/geckodriver/releases

After checking the selenium source code, I had found that the rule how they located these drivers in new selenium 3 API:

Invoke the WebDriver

org.openqa.selenium.chrome.ChromeDriver.ChromeDriver()

ChromeDriverService.createDefaultService();

new Builder().usingAnyFreePort().build();

org.openqa.selenium.remote.service.DriverService.Builder.build();

org.openqa.selenium.chrome.ChromeDriverService.Builder.findDefaultExecutable()

org.openqa.selenium.remote.service.DriverService.findExecutable(String, String, String, String)
 

String defaultPath = CommandLine.find(exeName);

String exePath = System.getProperty(exeProperty, defaultPath);

checkState(exePath != null,

"The path to the driver executable must be set by the %s system property;"

+ " for more information, see %s. "

+ "The latest version can be downloaded from %s",

exeProperty, exeDocs, exeDownload);

 

 

public String find(String named) {

File file = new File(named);

if (canExecute(file)) {

return named;

}

 

if (Platform.getCurrent().is(Platform.WINDOWS)) {

file = new File(named + ".exe");

if (canExecute(file)) {

return named + ".exe";

}

}

 

addPathFromEnvironment();

if (Platform.getCurrent().is(Platform.MAC)) {

addMacSpecificPath();

}

 

for (String pathSegment : pathSegmentBuilder.build()) {

for (String ending : ENDINGS) {

file = new File(pathSegment, named + ending);

if (canExecute(file)) {

return file.getAbsolutePath();

}

}

}

return null;

}

1. First option is place the driver file in your current WebDriver or RemoteWebDriver instance,for example:

If you current selenium server path is: /usr/selenium-server-version.jar ,then you must put the driver into this place

/usr and also MUST NOT change the driver’s name .

2. Add the driver into the PATH environment variable, in linux kernel system, you can put it into this place: /etc/paths.

For windows system you can put it in System environment or User environment Path variable .and also MUST NOT change the driver’s name.

3. Using programmatically java Code: System.setProperty(“”,””) here you can change the driver’s name.

Issues: Selenium Server is developed by Java, and using System.getEnv() to find the PATH variable ,so maybe the cache issue ,cannot located it correctly. When you changed the environment Path for chromedriver you need to restart the Java virtual machine again to make the changes affected.