事实证明，这是一种简单，标准的方法实现我想要的：

It turned out that there's a simple, standard way to achieve what I wanted:

import java.net.Authenticator;
import java.net.PasswordAuthentication;

Authenticator myAuth = new Authenticator() 
{
    @Override
    protected PasswordAuthentication getPasswordAuthentication()
    {
        return new PasswordAuthentication("german", "german".toCharArray());
    }
};

Authenticator.setDefault(myAuth);

没有自定义sun类或外部依赖项，也没有手动编码任何内容。

No custom "sun" classes or external dependencies, and no manually encode anything.

我知道BASIC安全性不是很安全，但我们也使用HTTPS。

I'm aware that BASIC security is not, well, secure, but we are also using HTTPS.