Télécharger le fichier en utilisant HtmlUnit

Je l'ai fait en fonction de votre post.. Remarque: vous pouvez modifier le type de contenu d'état pour télécharger uniquement type de fichier spécifique. par exemple.( application/octect-stream, application/pdf, etc).

package net.s4bdigital.export.main;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.htmlunit.HtmlUnitDriver;

import com.gargoylesoftware.htmlunit.ConfirmHandler;
import com.gargoylesoftware.htmlunit.Page;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.WebResponse;
import com.gargoylesoftware.htmlunit.WebWindowEvent;
import com.gargoylesoftware.htmlunit.WebWindowListener;
import com.gargoylesoftware.htmlunit.util.NameValuePair;

public class HtmlUnitDownloadFile {

    protected String baseUrl;
    protected static WebDriver driver;

    @Before
    public void openBrowser() {
        baseUrl = "http://localhost/teste.html";
        driver = new CustomHtmlUnitDriver();
        ((HtmlUnitDriver) driver).setJavascriptEnabled(true);

    }


    @Test
    public void downloadAFile() throws Exception {

        driver.get(baseUrl);
        driver.findElement(By.linkText("click to Downloadfile")).click();

    }

    public class CustomHtmlUnitDriver extends HtmlUnitDriver { 

          //This is the magic. Keep a reference to the client instance 
           protected WebClient modifyWebClient(WebClient client) { 


             ConfirmHandler okHandler = new ConfirmHandler(){
                    public boolean handleConfirm(Page page, String message) {
                        return true;
                    }
             };
             client.setConfirmHandler(okHandler);

             client.addWebWindowListener(new WebWindowListener() {

                public void webWindowOpened(WebWindowEvent event) {
                    //TODO Auto-generated method stub

                }

                public void webWindowContentChanged(WebWindowEvent event) {

                    WebResponse response = event.getWebWindow().getEnclosedPage().getWebResponse();
                    System.out.println(response.getLoadTime());
                    System.out.println(response.getStatusCode());
                    System.out.println(response.getContentType());

                    List<NameValuePair> headers = response.getResponseHeaders();
                    for(NameValuePair header: headers){
                        System.out.println(header.getName() + " : " + header.getValue());
                    }

                    //Change or add conditions for content-types that you would to like 
                    //receive like a file.
                    if(response.getContentType().equals("text/plain")){
                        getFileResponse(response, "target/testDownload.war");
                    }



                }

                public void webWindowClosed(WebWindowEvent event) {



                }
            });          

             return client; 
           } 


    } 

    public static void getFileResponse(WebResponse response, String fileName){

        InputStream inputStream = null;

        //write the inputStream to a FileOutputStream
        OutputStream outputStream = null; 

        try {       

            inputStream = response.getContentAsStream();

            //write the inputStream to a FileOutputStream
            outputStream = new FileOutputStream(new File(fileName));

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }

            System.out.println("Done!");

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (outputStream != null) {
                try {
                    //outputStream.flush();
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }

    }

}

 final WebClient webClient = new WebClient(BrowserVersion.CHROME);
        webClient.getOptions().setTimeout(2000);
        webClient.getOptions().setThrowExceptionOnScriptError(false);
        webClient.getOptions().setThrowExceptionOnFailingStatusCode(false);
        webClient.waitForBackgroundJavaScript(2000);

        //get General page
        final HtmlPage page = webClient.getPage("http://your");

        //get Frame
        final HtmlPage frame = ((HtmlPage) 
        page.getFrameByName("Frame").getEnclosedPage());

        webClient.setConfirmHandler(new ConfirmHandler() {
            public boolean handleConfirm(Page page, String message) {
                return true;
            }
        });

        //get element file
        final DomElement file = mainFrame.getElementByName("File");

        final InputStream xls =  file.click().getWebResponse().getContentAsStream();

        assertNotNull(xls);
    }