Spring RestTemplate无法解组包含“dtd>”的XML

Question

我称之为第三方提供的旧网络服务。我正在使用Spring RestTemplate：

HttpEntity<MyRequest> requestHttpEntity = new HttpEntity<>(requestBody, headers);
MyResponse response = restTemplate.postForEntity(url, requestHttpEntity, MyResponse.class);

我收到一个XML（我不能影响的格式，它是第三方服务）作为回复：

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE MyResponse SYSTEM "http://example.com:8080/some/path/MyResponse.dtd">

<MyResponse>
    ...
</MyResponse>

postForEntity()方法抛出异常

org.springframework.web.client.RestClientException: 
    Error while extracting response for type [class com.example.MyResponse] and content type [text/xml;charset=ISO-8859-1];
nested exception is org.springframework.http.converter.HttpMessageNotReadableException: 
    Could not unmarshal to [class com.example.MyResponse]: null;
nested exception is javax.xml.bind.UnmarshalException

- with linked exception:
     [org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 10;
     DOCTYPE is disallowed when the feature
     "http://apache.org/xml/features/disallow-doctype-decl" set to true.]

我在这里找到了http://apache.org/xml/features/disallow-doctype-decl特征的唯一明智的参考：https://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl

问题：如何在不完全避免Spring RestTemplate的自动行为的情况下自定义解组？我想强制unmarshaler接受包含DTD引用的XML元素。

这个问题与我的其他问题How to customize automatic marshaling in Spring RestTemplate to produce/modify XML headers (encoding, DOCTYPE)密切相关，但是提出的解决方案在这里并不容易适用。