Http Servlet request lose params from POST body after read it once

Question

I\'m trying to accessing two http request parameters in a Java Servlet filter, nothing new here, but was surprised to find that the parameters have already been consumed! Be

Answer 1

Just overwriting of getInputStream() did not work in my case. My server implementation seems to parse parameters without calling this method. I did not find any other way, but re-implement the all four getParameter* methods as well. Here is the code of getParameterMap (Apache Http Client and Google Guava library used):

@Override
public Map getParameterMap() {
    Iterable params = URLEncodedUtils.parse(getQueryString(), NullUtils.UTF8);

    try {
        String cts = getContentType();
        if (cts != null) {
            ContentType ct = ContentType.parse(cts);
            if (ct.getMimeType().equals(ContentType.APPLICATION_FORM_URLENCODED.getMimeType())) {
                List postParams = URLEncodedUtils.parse(IOUtils.toString(getReader()), NullUtils.UTF8);
                params = Iterables.concat(params, postParams);
            }
        }
    } catch (IOException e) {
        throw new IllegalStateException(e);
    }
    Map result = toMap(params);
    return result;
}

public static Map toMap(Iterable body) {
    Map result = new LinkedHashMap<>();
    for (NameValuePair e : body) {
        String key = e.getName();
        String value = e.getValue();
        if (result.containsKey(key)) {
            String[] newValue = ObjectArrays.concat(result.get(key), value);
            result.remove(key);
            result.put(key, newValue);
        } else {
            result.put(key, new String[] {value});
        }
    }
    return result;
}