用java代码实现firefox自动下载文件

题目：在启动firefox时，如何设置firefox的默认下载文件路径，让在需要下载的地方自动的把文件下载到设置的文件夹中去；
代码：

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebDriver.Navigation;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.firefox.FirefoxProfile;
import org.openqa.selenium.firefox.internal.ProfilesIni;

public class Mysavefiles {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        mydefault();

    }
    public static void mydefault(){
        ProfilesIni allprofiles = new ProfilesIni();
        FirefoxProfile profile = allprofiles.getProfile("default");
        profile.setPreference("browser.download.folderList", "2");
        profile.setPreference("browser.download.dir", "E:\\selenium");
        profile.setPreference("browser.download.useDownloadDir", true);
        profile.setPreference("browser.download.manager.showWhenStarting",false);
        profile.setPreference("browser.helperApps.neverAsk.saveToDisk", "application/octet-stream, application/vnd.ms-excel, text/csv, application/zip,application/exe");
        WebDriver driver = new FirefoxDriver(profile);
        Navigation navigation = driver.navigate();
        navigation.to("%202.14@67_136971.exe");
//        driver.get(");
        driver.close();
    }
}

一定要注意：browser.helperApps.neverAsk.saveToDisk这个属性值的配置，必须加上application/xxxx，不然一直会弹出下载提示框