HttpsURLConnection.getInputStream 在 Eclipse 中工作正常，但在导出代码并从命令行运行后服务器返回响应代码 503

Question

I use Eclipse and occasionally export my program and run it from the command line. The functionality is exactly the same except this one thing:

HttpsURLConnection reads some data from a website. This works fine when I run the code from Eclipse. However, after I export my code as Runnable JAR, this part of the program does not work: I get a

java.io.IOException: Server returned HTTP response code: 503

Here is the method that triggers this error:

private List<Event> parse(final String url) throws IOException {
    InputStream inputStream = null;
    try {
        URL u = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection)u.openConnection();
        con.setRequestProperty("User-Agent", "Mozilla/5.0 (compatible; Windows NT 6.1)");
        inputStream = con.getInputStream();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }
    final String page
        = org.apache.commons.io.IOUtils.toString(inputStream, java.nio.charset.StandardCharsets.US_ASCII);
    inputStream.close();
    ...
}

Please note that my program only visits this website once. It does not "harass" the server...

Answer 1

I replaced java in the command line with "C:\Program Files\Java\jdk-13.0.1\bin\java.exe" and now it works.

[I found out that's what Eclipse was doing by going to Project → Properties → Run/Debug Settings → Edit → Show Command Line].

I am not sure where exactly the plain java I was using before was pointing - and at this point, I don't intend to investigate.