XML外部实体注入：在此行显示错误DocumentBuilderFactory.newInstance（）。newDocumentBuilder（）。parse（new InputSource（sr））;

Question

URL configurlURL = new URL(configurl.toString()); // validate
String domainConfig = get(configurl.toString(), headers, null);

// find and get the schema file from the reference url
Document doc = null;
try (StringReader sr = new StringReader(domainConfig)) {
    doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new InputSource(sr));
}