使用Java从HTTPS URL下载文件

Question

我已经编写了一些代码来从网站下载文件.该代码适用于测试http网址.一旦我将URL更改为https,我就会有一个连接超时.

System.setProperty("http.proxyHost","trproxy.rwe.com") ;
System.setProperty("http.proxyPort", "80") ;
Authenticator.setDefault (new MyAuthenticator("USER","PW"));
//URL url = new URL("http","www.treasury.gov",80,"/ofac/downloads/sdn.csv",new    sun.net.www.protocol.http.Handler());  THIS WORKS
URL url = new URL("https", "downloads.elexonportal.co.uk",443,"/bmradataarchive/download?key=MYKEY&filename="+filename,new sun.net.www.protocol.https.Handler());
url.openConnection();
InputStream reader = url.openStream();
FileOutputStream writer = new FileOutputStream("C:/downloads/"+filename);

如果我将https网址复制到浏览器中,我会被问到我希望保存文件的位置,并且工作正常.任何帮助非常感谢.我试过这个 但是没用

谢谢克里斯