_java

Example

To start things off let's import our requisite classes (for annotations (e.g., org.junit.After, etc.), driving the browser with Selenium (e.g., org.openqa.selenium.WebDriver, etc.), matchers for our assertions (e.g., org.hamcrest.CoreMatchers, etc.), and an HTTP library to handle our HEAD request (e.g., org.apache.http.HttpResponse, etc.) and start our class with some setup and teardown methods.

// filename: DownloadFileRevisited.java
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import static org.hamcrest.CoreMatchers.*;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.MatcherAssert.assertThat;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpHead;
import org.apache.http.impl.client.HttpClientBuilder;

public class DownloadFileRevisited {
    WebDriver driver;

    @Before
    public void setUp() throws Exception {
        driver = new FirefoxDriver();
    }

    @After
    public void tearDown() throws Exception {
        driver.quit();
    }
// ...

Now we're ready to wire up our test.

It's just a simple matter of visiting the page with download links, grabbing a URL from one of them, and performing a HEAD request with it.

// filename: DownloadFileRevisited.java
// ...
    @Test
    public void downloadFileRevisitedTest() throws Exception {
        driver.get("http://the-internet.herokuapp.com/download");
        String link = driver.findElement(By.cssSelector(".example a:nth-of-type(1)")).getAttribute("href");

        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpHead request = new HttpHead(link);
        HttpResponse response = httpClient.execute(request);
        String contentType = response.getFirstHeader("Content-Type").getValue();
        int contentLength = Integer.parseInt(response.getFirstHeader("Content-Length").getValue());

        assertThat(contentType, is("application/octet-stream"));
        assertThat(contentLength, is(not(0)));
    }

}

Once we receive the response we check it's header for the content type (e.g., response.getFirstHeader("Content-Type")) and content length (e.g., response.getFirstHeader("Content-Length")) to make sure the file is the correct type and not empty.

Expected Behavior

When you save this and run it (e.g., mvn clean install from the command-line) here is what will happen:

• Open the browser
• Load the page
• Grab the URL of the first download link
• Perform a HEAD request against it with an HTTP library
• Store the response headers
• Check the response headers to see that the file type is correct
• Check the response headers to see that the file is not empty
• Close the browser

Summary

Compared to the browser specific configuration with Selenium this is hands-down a leaner, faster, and more maintainable approach.

Thanks to Roman Isko for contributing the initial Java code for this tip.

Happy Testing!