ui自动化利用WatchService去给下载事件进行断言

项目中，存在点击后下载的业务流程，而selenium本身没有很好的方法去断言文件是否下载成功。此时我们可以通过WatchService去监听目录文件，来确定文件是否下载成功。

//监听所下载的文件名

public static String getDownloadedDocumentName(String filepath, String filename)

{

String downloadedFileName = null;

boolean valid = true;

boolean found = false;

//default timeout in seconds

long timeOut = 30;

try

{

Path downloadFolderPath = Paths.get(filepath);

WatchService watchService = FileSystems.getDefault().newWatchService();

downloadFolderPath.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);

long startTime = System.currentTimeMillis();

do

{

WatchKey watchKey;

watchKey = watchService.poll(timeOut,TimeUnit.SECONDS);

long currentTime = (System.currentTimeMillis()-startTime)/1000;

if(currentTime>timeOut)

{

System.out.println("Download operation timed out.. Expected file was not downloaded");

return downloadedFileName;

}

for (WatchEvent<?> event: watchKey.pollEvents())

{

WatchEvent.Kind<?> kind = event.kind();

if (kind.equals(StandardWatchEventKinds.ENTRY_CREATE))

{

String fileName = event.context().toString();

System.out.println("New File Created:" + fileName);

if(fileName.endsWith(filename))

{

downloadedFileName = fileName;

System.out.println("Downloaded file found with extension " + filename + ". File name is " + fileName);

Thread.sleep(500);

found = true;

break;

}

}

}

if(found)

{

return downloadedFileName;

}

else

{

currentTime = (System.currentTimeMillis()-startTime)/1000;

if(currentTime>timeOut)

{

System.out.println("Failed to download expected file");

return downloadedFileName;

}

valid = watchKey.reset();

}

} while (valid);

}

catch (InterruptedException e)

{

System.out.println("Interrupted error - " + e.getMessage());

e.printStackTrace();

}

catch (NullPointerException e)

{

System.out.println("Download operation timed out.. Expected file was not downloaded");

}

catch (Exception e)

{

System.out.println("Error occured - " + e.getMessage());

e.printStackTrace();

}

return downloadedFileName;

}

//确认文件下载是否完成

public static Boolean isFileDownloaded_Ext(String filepath, String filename) {

boolean flag=false;

File dir = new File(filepath);

File[] files = dir.listFiles();

if (files == null || files.length == 0) {

flag = false;

}

for (int i = 0; i <files.length; i++) {

if(files[i].getName().contains(filename)) {

flag=true;

}

}

return flag;

}

运行结果

通过上面的方法即可得到下载后的文件名，然后通过下载的文件和用例中的预期做断言即可