import org.apache.oltu.oauth2.rs.request.OAuthAccessResourceRequest; //导入依赖的package包/类
protected boolean CheckAccessToken(HttpServletRequest request, HttpServletResponse response)
    throws IOException, OAuthSystemException {
  try {
    String accessToken = new OAuthAccessResourceRequest(request).getAccessToken();
    if (oAuthService.checkAccessToken(accessToken, request))
      return true;
    // because OLTU client not process error in response header
    // so still send JSON data back, the client need process this error
    I18N i18n = new I18N(request.getLocale());
    return ResponseUtils.processResponse(response, null,
        ResponseUtils.responseInvalidToken(i18n.getString("INVALID_TOKEN")));
  } catch (OAuthProblemException ex) {
    if (OAuthUtils.isEmpty(ex.getError()))
      return ResponseUtils.processResponse(response, null,
          ResponseUtils.responseInvalidRequest(ex.getDescription()));
    return ResponseUtils.processResponse(response, null,
        OAuthRSResponse.errorResponse(HttpServletResponse.SC_UNAUTHORIZED).error(ex));
  }
}
 

import org.apache.oltu.oauth2.rs.request.OAuthAccessResourceRequest; //导入依赖的package包/类
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;

    try {

        // Make an OAuth Request out of this servlet request
        OAuthAccessResourceRequest oauthRequest = new OAuthAccessResourceRequest(req,
                parameterStyles);

        // Get the access token
        String accessToken = oauthRequest.getAccessToken();

        final OAuthDecision decision = provider.validateRequest(realm, accessToken, req);

        final Principal principal = decision.getPrincipal();

        HttpServletRequest newRequest = new HttpServletRequestWrapper((HttpServletRequest) request) {
            @Override
            public String getRemoteUser() {
                return principal != null ? principal.getName() : null;
            }

            @Override
            public Principal getUserPrincipal() {
                return principal;
            }

        };

        newRequest.setAttribute(OAuth.OAUTH_CLIENT_ID, decision.getOAuthClient().getClientId());

        chain.doFilter(newRequest, response);

    } catch (OAuthSystemException e1) {
        throw new ServletException(e1);
    } catch (OAuthProblemException e) {
        respondWithError(res, e);
    }

}