[Solved] how to upload a file using selenium

You can't access native controls with Selenium. But one trick you can use is to launch the file upload dialog using selenium, then use java.awt utilities to load a string into the clipboard and invoke the keystrokes to paste it.

import java.awt.Toolkit;
import java.awt.Robot;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyEvent;

...

CommandCenter cc = CommandCenter.login("CustomerATransMgr");
cc.openTabFromMenu("Tools", "Upload", "Partner");

WebElement input = cc.getUIContext().waitUntilElementExists(By.name("dataFile"));
new Actions(cc.getDriver()).doubleClick(input).build().perform();
Thread.sleep(1000); // we have no choice here but to wait a moment for the popup to open

Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection("C:\Temp\myFile.txt"), null);
Robot robot = new Robot();
// Paste filename 
robot.keyPress(KeyEvent.VK_CONTROL);
robot.keyPress(KeyEvent.VK_V);
robot.keyRelease(KeyEvent.VK_V);
robot.keyRelease(KeyEvent.VK_CONTROL);
// Hit "enter" to accept
robot.keyPress(KeyEvent.VK_ENTER);
robot.keyRelease(KeyEvent.VK_ENTER);

We had some issues with awt approach. Thanks to Yusuf, he came up with following logic.

@Test
public void testEnterpriseUpload() throws Exception {
  Tab tab = cc.openTabFromMenu("Uploads", "Upload Onboard Requests");
  tab.select();
  context.waitUntilUnmask();
  WebElement input = cc.getUIContext().waitUntilElementExists(By.name("dataFile"));
  String datasetDir = new TestEnv().getInstallRootDir().toString();
  String fileLocation = datasetDir+File.separator+"..\\dataset\\CommunityMasterData_dataset"+File.separator+"xml"+File.separator+"EReq.csv";
  input.sendKeys(fileLocation);
  ((JavascriptExecutor) context.getDriver()).executeScript("submitFn();");
}