@Override
protected String getMediaTypeKey(NativeWebRequest webRequest) {
HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
if (request == null) {
logger.warn("An HttpServletRequest is required to determine the media type key");
return null;
}
String path = PATH_HELPER.getLookupPathForRequest(request);
String filename = WebUtils.extractFullFilenameFromUrlPath(path);
String extension = StringUtils.getFilenameExtension(filename);
return (StringUtils.hasText(extension)) ? extension.toLowerCase(Locale.ENGLISH) : null;
}
/**
* Determines the list of {@link MediaType} for the given {@link HttpServletRequest}.
*
* <p>The default implementation invokes {@link #getMediaTypeFromFilename(String)} if {@linkplain
* #setFavorPathExtension favorPathExtension} property is <code>true</code>. If the property is
* <code>false</code>, or when a media type cannot be determined from the request path, this
* method will inspect the {@code Accept} header of the request.
*
* <p>This method can be overridden to provide a different algorithm.
*
* @param request the current servlet request
* @return the list of media types requested, if any
*/
protected List<MediaType> getMediaTypes(HttpServletRequest request) {
if (this.favorPathExtension) {
String requestUri = urlPathHelper.getLookupPathForRequest(request);
String filename = WebUtils.extractFullFilenameFromUrlPath(requestUri);
MediaType mediaType = getMediaTypeFromFilename(filename);
if (mediaType != null) {
if (logger.isDebugEnabled()) {
logger.debug(
"Requested media type is '" + mediaType + "' (based on filename '" + filename + "')");
}
return Collections.singletonList(mediaType);
}
}
if (this.favorParameter) {
if (request.getParameter(this.parameterName) != null) {
String parameterValue = request.getParameter(this.parameterName);
MediaType mediaType = getMediaTypeFromParameter(parameterValue);
if (mediaType != null) {
if (logger.isDebugEnabled()) {
logger.debug(
"Requested media type is '"
+ mediaType
+ "' (based on parameter '"
+ this.parameterName
+ "'='"
+ parameterValue
+ "')");
}
return Collections.singletonList(mediaType);
}
}
}
if (!this.ignoreAcceptHeader) {
String acceptHeader = request.getHeader(ACCEPT_HEADER);
if (StringUtils.hasText(acceptHeader)) {
try {
List<MediaType> acceptableMediaTypes = MediaType.parseMediaTypes(acceptHeader);
List<MediaType> producibleMediaTypes = getProducibleMediaTypes(request);
Set<MediaType> compatibleMediaTypes = new LinkedHashSet<MediaType>();
for (MediaType acceptable : acceptableMediaTypes) {
for (MediaType producible : producibleMediaTypes) {
if (acceptable.isCompatibleWith(producible)) {
compatibleMediaTypes.add(getMostSpecificMediaType(acceptable, producible));
}
}
}
List<MediaType> mediaTypes = new ArrayList<MediaType>(compatibleMediaTypes);
MediaType.sortByQualityValue(mediaTypes);
if (logger.isDebugEnabled()) {
logger.debug(
"Requested media types are "
+ mediaTypes
+ " based on Accept header types "
+ "and producible media types "
+ producibleMediaTypes
+ ")");
}
return mediaTypes;
} catch (IllegalArgumentException ex) {
if (logger.isDebugEnabled()) {
logger.debug(
"Could not parse accept header [" + acceptHeader + "]: " + ex.getMessage());
}
return null;
}
}
}
if (this.defaultContentType != null) {
if (logger.isDebugEnabled()) {
logger.debug(
"Requested media types is "
+ this.defaultContentType
+ " (based on defaultContentType property)");
}
return Collections.singletonList(this.defaultContentType);
} else {
return Collections.emptyList();
}
}