javabasic-authenticationapache-commons-httpclient

Preemptive Basic authentication with Apache HttpClient 4


Is there an easier way to setup the http client for preemptive basic authentication than what described here?
In previous version (3.x) it used to be a simple method call (eg, httpClient.getParams().setAuthenticationPreemptive(true)).
The main thing I want to avoid is adding the BasicHttpContext to each method I execute.


Solution

  • It's difficult to do this without passing a context through every time, but you can probably do it by using a request interceptor. Here is some code that we use (found from their JIRA, iirc):

    // Pre-emptive authentication to speed things up
    BasicHttpContext localContext = new BasicHttpContext();
    
    BasicScheme basicAuth = new BasicScheme();
    localContext.setAttribute("preemptive-auth", basicAuth);
    
    httpClient.addRequestInterceptor(new PreemptiveAuthInterceptor(), 0);
    
    (...)
    
    static class PreemptiveAuthInterceptor implements HttpRequestInterceptor {
    
        public void process(final HttpRequest request, final HttpContext context) throws HttpException, IOException {
            AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
    
            // If no auth scheme avaialble yet, try to initialize it
            // preemptively
            if (authState.getAuthScheme() == null) {
                AuthScheme authScheme = (AuthScheme) context.getAttribute("preemptive-auth");
                CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
                HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
                if (authScheme != null) {
                    Credentials creds = credsProvider.getCredentials(new AuthScope(targetHost.getHostName(), targetHost.getPort()));
                    if (creds == null) {
                        throw new HttpException("No credentials for preemptive authentication");
                    }
                    authState.setAuthScheme(authScheme);
                    authState.setCredentials(creds);
                }
            }
    
        }
    
    }