public Response intercept()

in aws-android-sdk-appsync/src/main/java/com/amazonaws/mobileconnectors/appsync/sigv4/AppSyncSigV4SignerInterceptor.java [116:199]
59 lines of code
13 McCabe index (conditional complexity)

    public Response intercept(Chain chain) throws IOException {
        Log.d(TAG, "Signer Interceptor called");

        Request req = chain.request();

        //Clone the request into a new DefaultRequest object and populate it with credentials
        DefaultRequest dr = new DefaultRequest(SERVICE_NAME);
        //set the endpoint
        dr.setEndpoint(req.url().uri());
        //copy all the headers
        for(String headerName : req.headers().names()) {
            dr.addHeader(headerName, req.header(headerName));
        }
        //set the http method
        dr.setHttpMethod(HttpMethodName.valueOf(req.method()));

        //Add User Agent
        String userAgent = StringUtils.toHumanReadableAscii(VersionInfoUtils.getUserAgent());
        dr.addHeader(HEADER_USER_AGENT, userAgent);

        //write the body to a byte array stream.
        final Buffer buffer = new Buffer();
        req.body().writeTo(buffer);
        dr.setContent(buffer.inputStream());

        Buffer body = buffer.clone();

        //Sign or Decorate request with the required headers
        if (AuthMode.IAM.equals(authMode)) {
            //get the aws credentials from provider.
            try {
                //Get credentials - This will refresh the credentials if necessary
                AWSCredentials credentials = this.credentialsProvider.getCredentials();
                //sign the request
                new AppSyncV4Signer(this.awsRegion).sign(dr, credentials);
            } catch (Exception e) {
                throw new IOException("Failed to read credentials to sign the request.", e);
            }
        } else if (AuthMode.API_KEY.equals(authMode)) {
            dr.addHeader(X_API_KEY, apiKey.getAPIKey());
            if (subscriberUUID != null ) {
                Log.d(TAG,"Subscriber ID is " + subscriberUUID);
                dr.addHeader(X_AMZ_SUBSCRIBER_ID, subscriberUUID);
            }

        } else if (AuthMode.USERPOOLS_AUTHORIZATION_TOKEN.equals(authMode)) {
            try {
                dr.addHeader(AUTHORIZATION, cognitoUserPoolsAuthProvider.getLatestAuthToken());
            } catch (Exception e) {
                IOException ioe = new IOException("Failed to retrieve Cognito User Pools token.", e);
                throw ioe;
            }
        } else if (AuthMode.OIDC_AUTHORIZATION_TOKEN.equals(authMode)) {
            try {
                dr.addHeader(AUTHORIZATION, oidcAuthProvider.getLatestAuthToken());
            } catch (Exception e) {
                IOException ioe = new IOException("Failed to retrieve OIDC token.", e);
                throw ioe;
            }
        } else if (AuthMode.AWS_LAMBDA_AUTHORIZATION_TOKEN.equals(authMode)) {
            try {
                dr.addHeader(AUTHORIZATION, awsLambdaAuthProvider.getLatestAuthToken());
            } catch (Exception e) {
                IOException ioe = new IOException("Failed to retrieve AWS Lambda authorization token.", e);
                throw ioe;
            }
        }

        //Copy the signed/credentialed request back into an OKHTTP Request object.
        Request.Builder okReqBuilder = new Request.Builder();

        //set the headers from default request, since it contains the signed headers as well.
        for (Map.Entry<String, String> e : (Set<Map.Entry<String, String>>)dr.getHeaders().entrySet()) {
            okReqBuilder.addHeader(e.getKey(), e.getValue());
        }

        //Set the URL and Method
        okReqBuilder.url(req.url());
        okReqBuilder.method(req.method(), RequestBody.create(JSON_MEDIA_TYPE, body.readByteArray()));

        //continue with chain.
        Response res = chain.proceed(okReqBuilder.build());
        return res;
    }