Refactor Needles Interfaces and Rename "process" to "backend"

Reason:
- Interfaces with a single method can be replaced with
  interfaces from java.util.function.
- Less interfaces = less code = less maintenance!
- Spring can inject beans by name so we name dependencies correctly
  to prevent ambiguity.

Others:
- Rename process to backend since backend gives a better description
  of its components.

18 files changed, 114 insertions, 158 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/process/SingleThreadedDeliveryPipeline.java b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
index 445f386..06eba80 100644
--- a/src/main/java/at/gv/egiz/moazs/process/SingleThreadedDeliveryPipeline.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
@@ -1,4 +1,4 @@
-package at.gv.egiz.moazs.process;
+package at.gv.egiz.moazs.backend;
 
 
 import at.gv.egiz.moazs.MoaZSException;
@@ -7,8 +7,6 @@ import at.gv.egiz.moazs.client.TnvzHelper;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.Mzs2MsgConverter;
 import at.gv.egiz.moazs.scheme.RequestStatusResponse;
-import at.gv.egiz.moazs.verify.MsgResponseVerifier;
-import at.gv.egiz.moazs.verify.SignatureVerifier;
 import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
 import at.gv.zustellung.msg.xsd.App2ZusePort;
 import at.gv.zustellung.tnvz.xsd.TNVZServicePort;
@@ -17,15 +15,17 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Profile;
 import org.springframework.stereotype.Component;
 
+import java.util.function.Consumer;
+
 import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
 import static at.gv.egiz.moazs.scheme.RequestStatusResponse.generateErrorFromException;
 import static java.lang.String.format;
 
 @Component
 @Profile("!cluster")
-public class SingleThreadedDeliveryPipeline implements DeliveryPipeline {
+public class DeliveryRequestBackend implements Consumer<String> {
 
-    private static final Logger log = Logger.getLogger(SingleThreadedDeliveryPipeline.class);
+    private static final Logger log = Logger.getLogger(DeliveryRequestBackend.class);
     private static final String MZS_PIPELINE_ERROR_MSG =
             "An error occured while processing the DeliveryRequest with AppDeliveryID=%s. ";
 
@@ -33,23 +33,32 @@ public class SingleThreadedDeliveryPipeline implements DeliveryPipeline {
     private final TnvzHelper tnvzHelper;
     private final Mzs2MsgConverter converter;
     private final ClientFactory clientFactory;
-    private final SignatureVerifier verifier;
+    private final Consumer<byte[]> signatureVerifier;
 
     @Autowired
-    public SingleThreadedDeliveryPipeline(DeliveryRepository repository,
-                                          TnvzHelper tnvzHelper,
-                                          Mzs2MsgConverter converter,
-                                          ClientFactory clientFactory,
-                                          SignatureVerifier verifier) {
+    public DeliveryRequestBackend(DeliveryRepository repository,
+                                  TnvzHelper tnvzHelper,
+                                  Mzs2MsgConverter converter,
+                                  ClientFactory clientFactory,
+                                  Consumer<byte[]> signatureVerifier) {
         this.repository = repository;
         this.tnvzHelper = tnvzHelper;
         this.converter = converter;
         this.clientFactory = clientFactory;
-        this.verifier = verifier;
+        this.signatureVerifier = signatureVerifier;
     }
 
+    /**
+     * Performs all {@code DeliveryRequest}'s Back-End Tasks.
+     *
+     * Fetches {@code DeliveryRequest} referred by appDeliveryID from
+     * {@code DeliveryRepository}, makes sure that all necessary
+     * tasks (query tnvz, query msg, accept status) are executed and
+     * stores the response back to {@code DeliveryRepository}.
+     * @param appDeliveryID
+     */
     @Override
-    public void processRequest(String appDeliveryID) {
+    public void accept(String appDeliveryID) {
 
         var exceptionBuilder = moaZSExceptionBuilder();
 
@@ -79,9 +88,9 @@ public class SingleThreadedDeliveryPipeline implements DeliveryPipeline {
     private void verifySignedStatus(String responseID, String appDeliveryID, MoaZSException.Builder exceptionBuilder) throws MoaZSException {
         try {
             var signedStatus = repository.retrieveBinaryResponse(responseID).get();
-            verifier.verify(signedStatus);
+            signatureVerifier.accept(signedStatus);
         } catch (MoaZSException ex) {
-            throw exceptionBuilder.withMessage(format(MsgResponseVerifier.MOASP_SIGNATURE_INVALID_ERROR_MSG, appDeliveryID))
+            throw exceptionBuilder.withMessage(format(MsgResponseBackend.MOASP_SIGNATURE_INVALID_ERROR_MSG, appDeliveryID))
                     .withErrorCode(MoaZSException.ERROR_MOASP_SIGNATURE_INVALID)
                     .withCause(ex)
                     .build();
diff --git a/src/main/java/at/gv/egiz/moazs/verify/MsgResponseVerifier.java b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
index 9c8b17c..414c2dc 100644
--- a/src/main/java/at/gv/egiz/moazs/verify/MsgResponseVerifier.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
@@ -1,4 +1,4 @@
-package at.gv.egiz.moazs.verify;
+package at.gv.egiz.moazs.backend;
 
 import at.gv.egiz.moazs.MoaZSException;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
@@ -9,23 +9,44 @@ import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
 import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
 import static java.lang.String.format;
+import static java.util.concurrent.CompletableFuture.supplyAsync;
 
 @Component
-public class MsgResponseVerifier {
+public class MsgResponseBackend implements Consumer<String> {
 
     private static final Logger log = LoggerFactory.getLogger(MsgService.class);
+
     public static final String MOASP_SIGNATURE_INVALID_ERROR_MSG = "Signature of Msg Response " +
             "with AppDeliveryID=%s is not valid.";
 
     private final DeliveryRepository repository;
-    private final SignatureVerifier verifier;
+    private final Consumer<byte[]> signatureVerifier;
+    private final Function<MsgResponse, CompletableFuture<Void>> sink;
 
     @Autowired
-    public MsgResponseVerifier(DeliveryRepository repository, SignatureVerifier verifier) {
+    public MsgResponseBackend(DeliveryRepository repository,
+                              Consumer<byte[]> signatureVerifier,
+                              Function<MsgResponse, CompletableFuture<Void>> sink) {
         this.repository = repository;
-        this.verifier = verifier;
+        this.signatureVerifier = signatureVerifier;
+        this.sink = sink;
+    }
+
+    /**
+     * Performs all {@code MsgResponse}'s Back-End Tasks, such as verifying
+     * its signature and archiving the response.
+     *
+     * @param responseID refers to MsgResponse Object.
+     */
+    @Override
+    public void accept(String responseID) {
+        supplyAsync(() -> verify(responseID)).thenAcceptAsync(sink::apply);
     }
 
     public MsgResponse verify(String responseID) {
@@ -36,7 +57,7 @@ public class MsgResponseVerifier {
         var binaryResponse = repository.retrieveBinaryResponse(responseID).get();
 
         try {
-            verifier.verify(binaryResponse);
+            signatureVerifier.accept(binaryResponse);
             return response;
         } catch (MoaZSException ex) {
             log.error(ex.getMessage(), ex);
diff --git a/src/main/java/at/gv/egiz/moazs/process/SaveResponseToFileSink.java b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
index 09d8570..02771a9 100644
--- a/src/main/java/at/gv/egiz/moazs/process/SaveResponseToFileSink.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
@@ -1,4 +1,4 @@
-package at.gv.egiz.moazs.process;
+package at.gv.egiz.moazs.backend;
 
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.Marshaller;
@@ -15,6 +15,7 @@ import java.nio.charset.StandardCharsets;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.concurrent.CompletableFuture;
+import java.util.function.Function;
 
 import static at.gv.egiz.moazs.MoaZSException.moaZSException;
 import static java.lang.String.format;
@@ -22,7 +23,7 @@ import static java.util.concurrent.CompletableFuture.allOf;
 import static java.util.concurrent.CompletableFuture.supplyAsync;
 
 @Component
-public class SaveResponseToFileSink implements MsgResponseSink {
+public class SaveResponseToFileSink implements Function<MsgResponse, CompletableFuture<Void>> {
 
     private static final Logger log = LoggerFactory.getLogger(SaveResponseToFileSink.class);
     private static final String SAVING_FAILED_MSG = "Could not save response with AppDeliveryId=%s.";
@@ -41,7 +42,7 @@ public class SaveResponseToFileSink implements MsgResponseSink {
     }
 
     @Override
-    public CompletableFuture<Void> handle(MsgResponse response) {
+    public CompletableFuture<Void> apply(MsgResponse response) {
 
         var responseID = response.getResponseID();
 
@@ -84,4 +85,5 @@ public class SaveResponseToFileSink implements MsgResponseSink {
             throw moaZSException(e.getMessage(), e);
         }
     }
+
 }
diff --git a/src/main/java/at/gv/egiz/moazs/verify/MoaSPSSSignatureVerifier.java b/src/main/java/at/gv/egiz/moazs/backend/SignatureVerifier.java
index 5220c3b..e9c5387 100644
--- a/src/main/java/at/gv/egiz/moazs/verify/MoaSPSSSignatureVerifier.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/SignatureVerifier.java
@@ -1,4 +1,4 @@
-package at.gv.egiz.moazs.verify;
+package at.gv.egiz.moazs.backend;
 
 import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.ISignatureVerificationService;
 import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.data.IXMLSignatureVerificationResponse;
@@ -6,31 +6,36 @@ import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.exceptions.MOASigServ
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.function.Consumer;
+
 import static at.gv.egiz.moazs.MoaZSException.moaZSException;
 import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
-import static java.lang.String.*;
+import static java.lang.String.format;
 
-public class MoaSPSSSignatureVerifier implements SignatureVerifier {
+public class SignatureVerifier implements Consumer<byte[]> {
 
-    private static final Logger log = LoggerFactory.getLogger(MoaSPSSSignatureVerifier.class);
+    private static final Logger log = LoggerFactory.getLogger(SignatureVerifier.class);
+    private static final int OK_CODE = 0;
 
     private final ISignatureVerificationService service;
-
     private final String trustProfile;
-
     private final boolean isManifestCheckActive;
 
-    private static final int OK_CODE = 0;
-
-    public MoaSPSSSignatureVerifier(ISignatureVerificationService service,
+    public SignatureVerifier(ISignatureVerificationService service,
                                     String trustProfile, boolean isManifestCheckActive) {
         this.service = service;
         this.trustProfile = trustProfile;
         this.isManifestCheckActive = isManifestCheckActive;
     }
 
+    /**
+     * Verifies the signature of a signed XML document. Throws a at.gv.egiz.moazs.MoaZSException exception
+     * if the validation fails.
+     * @param signedXMLdocument
+     * @throws at.gv.egiz.moazs.MoaZSException
+     */
     @Override
-    public void verify(byte[] signedXMLdocument) {
+    public void accept(byte[] signedXMLdocument) {
 
         try {
             var response = service.verifyXMLSignature(signedXMLdocument, trustProfile);
@@ -82,7 +87,7 @@ public class MoaSPSSSignatureVerifier implements SignatureVerifier {
             }
 
         } catch (MOASigServiceException e) {
-            throw moaZSExceptionBuilder("Could not verify the XML signature.")
+            throw moaZSExceptionBuilder("Could not accept the XML signature.")
                     .withCause(e)
                     .build();
         }
diff --git a/src/main/java/at/gv/egiz/moazs/config/MoaSigConfig.java b/src/main/java/at/gv/egiz/moazs/config/MoaSigConfig.java
index 0b7bdc7..e02c11d 100644
--- a/src/main/java/at/gv/egiz/moazs/config/MoaSigConfig.java
+++ b/src/main/java/at/gv/egiz/moazs/config/MoaSigConfig.java
@@ -3,8 +3,7 @@ package at.gv.egiz.moazs.config;
 import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.ISignatureVerificationService;
 import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.impl.SignatureVerificationService;
 import at.gv.egiz.moazs.util.FileUtils;
-import at.gv.egiz.moazs.verify.MoaSPSSSignatureVerifier;
-import at.gv.egiz.moazs.verify.SignatureVerifier;
+import at.gv.egiz.moazs.backend.SignatureVerifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -14,6 +13,7 @@ import org.springframework.context.annotation.Configuration;
 
 import java.io.File;
 import java.io.FileNotFoundException;
+import java.util.function.Consumer;
 
 
 @Configuration
@@ -62,8 +62,6 @@ public class MoaSigConfig {
         }
     }
 
-
-
     private void fallBackToSpringEnvForJavaxNetSSLStoreTypeProperty() {
         if (System.getProperty(JAVAX_SSL_TRUSTSTORE_TYPE_PROPERTY) == null) {
             log.info(SET_PROPERTY_MSG_TEMPLATE, JAVAX_SSL_TRUSTSTORE_TYPE_PROPERTY, trustStoreType);
@@ -87,11 +85,11 @@ public class MoaSigConfig {
     }
 
     @Bean
-    public SignatureVerifier signatureVerifier(@Value("${moa.spss.is-active}") boolean isMoaSPSSActive,
-                                               @Value("${moa.spss.is-manifest-check-active}") boolean isManifestCheckActive) {
+    public Consumer<byte[]> signatureVerifier(@Value("${moa.spss.is-active}") boolean isMoaSPSSActive,
+                                              @Value("${moa.spss.is-manifest-check-active}") boolean isManifestCheckActive) {
         if (isMoaSPSSActive) {
             log.info("Moa SPSS is active. Signatures in SOAP Messages will be verified.");
-            return new MoaSPSSSignatureVerifier(moaSigVerifyService(), defaultTrustProfile, isManifestCheckActive);
+            return new SignatureVerifier(moaSigVerifyService(), defaultTrustProfile, isManifestCheckActive);
         } else {
             log.warn("Moa SPSS is not active. Signatures in SOAP Messages will not be verified.");
             return signedXMLdocument -> {};
diff --git a/src/main/java/at/gv/egiz/moazs/config/PreprocessConfig.java b/src/main/java/at/gv/egiz/moazs/config/PreprocessConfig.java
index 76bfb30..29797dd 100644
--- a/src/main/java/at/gv/egiz/moazs/config/PreprocessConfig.java
+++ b/src/main/java/at/gv/egiz/moazs/config/PreprocessConfig.java
@@ -21,15 +21,14 @@ public class PreprocessConfig {
         return generator.generate();
     }
 
-    @Value("${verify-completeness-of-default-delivery-request-configuration:true}")
-    private boolean verifyCompletenessOfDefaultConfiguration;
-
     @Bean
     @Autowired
     public ConfigProfileGenerator configProfileGenerator(
             SpringPropertiesFacade properties,
             MzsDeliveryRequestValidator validator,
-            ConfigUtil util) {
+            ConfigUtil util,
+            @Value("${verify-completeness-of-default-delivery-request-configuration:true}")
+                    boolean verifyCompletenessOfDefaultConfiguration) {
 
         return configProfileGeneratorBuilder()
                 .withProperties(properties)
diff --git a/src/main/java/at/gv/egiz/moazs/config/ServicesConfig.java b/src/main/java/at/gv/egiz/moazs/config/ServicesConfig.java
index 42019b1..c16dfd2 100644
--- a/src/main/java/at/gv/egiz/moazs/config/ServicesConfig.java
+++ b/src/main/java/at/gv/egiz/moazs/config/ServicesConfig.java
@@ -38,7 +38,8 @@ public class ServicesConfig {
         return new Zuse2AppPortService();
     }
 
-    @Bean public App2Mzs app2mzs() {
+    @Bean
+    public App2Mzs app2mzs() {
         return new App2Mzs();
     }
 
diff --git a/src/main/java/at/gv/egiz/moazs/process/DeliveryPipeline.java b/src/main/java/at/gv/egiz/moazs/process/DeliveryPipeline.java
deleted file mode 100644
index 506dd1f..0000000
--- a/src/main/java/at/gv/egiz/moazs/process/DeliveryPipeline.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package at.gv.egiz.moazs.process;
-
-
-public interface DeliveryPipeline {
-
-    /**
-     * Performs all {@code DeliveryRequest}'s Back-End Tasks.
-     *
-     * Fetches {@code DeliveryRequest} referred by appDeliveryId from
-     * {@code DeliveryRepository}, makes sure that all necessary
-     * tasks (query tnvz, query msg, verify status) are executed and
-     * stores the response back to {@code DeliveryRepository}.
-     * @param appDeliveryId
-     */
-    void processRequest(String appDeliveryId);
-
-}
diff --git a/src/main/java/at/gv/egiz/moazs/process/MsgResponseHandler.java b/src/main/java/at/gv/egiz/moazs/process/MsgResponseHandler.java
deleted file mode 100644
index 5a7d39b..0000000
--- a/src/main/java/at/gv/egiz/moazs/process/MsgResponseHandler.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package at.gv.egiz.moazs.process;
-
-public interface MsgResponseHandler {
-
-    void handle(String id);
-
-}
diff --git a/src/main/java/at/gv/egiz/moazs/process/MsgResponseSink.java b/src/main/java/at/gv/egiz/moazs/process/MsgResponseSink.java
deleted file mode 100644
index 67348fc..0000000
--- a/src/main/java/at/gv/egiz/moazs/process/MsgResponseSink.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package at.gv.egiz.moazs.process;
-
-import at.gv.egiz.moazs.scheme.MsgResponse;
-
-import java.util.concurrent.CompletableFuture;
-
-public interface MsgResponseSink {
-
-    CompletableFuture<Void> handle(MsgResponse response);
-
-}
diff --git a/src/main/java/at/gv/egiz/moazs/process/SingleNodeResponseHandler.java b/src/main/java/at/gv/egiz/moazs/process/SingleNodeResponseHandler.java
deleted file mode 100644
index 65f5eed..0000000
--- a/src/main/java/at/gv/egiz/moazs/process/SingleNodeResponseHandler.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package at.gv.egiz.moazs.process;
-
-import at.gv.egiz.moazs.verify.MsgResponseVerifier;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
-
-import static java.util.concurrent.CompletableFuture.supplyAsync;
-
-@Component
-public class SingleNodeResponseHandler implements MsgResponseHandler {
-
-    private final MsgResponseVerifier verifier;
-    private final MsgResponseSink sink;
-
-    @Autowired
-    public SingleNodeResponseHandler(MsgResponseVerifier verifier, MsgResponseSink sink) {
-        this.verifier = verifier;
-        this.sink = sink;
-    }
-
-    @Override
-    public void handle(String responseID) {
-        supplyAsync(() -> verifier.verify(responseID))
-                .thenAcceptAsync(response -> sink.handle(response));
-    }
-}
diff --git a/src/main/java/at/gv/egiz/moazs/service/MsgService.java b/src/main/java/at/gv/egiz/moazs/service/MsgService.java
index 87644a0..9f94cb3 100644
--- a/src/main/java/at/gv/egiz/moazs/service/MsgService.java
+++ b/src/main/java/at/gv/egiz/moazs/service/MsgService.java
@@ -1,5 +1,4 @@
 package at.gv.egiz.moazs.service;
-import at.gv.egiz.moazs.process.MsgResponseHandler;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.MsgResponse;
 import at.gv.egiz.moazs.scheme.NameSpace;
@@ -10,6 +9,8 @@ import org.apache.cxf.annotations.SchemaValidation;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+import java.util.function.Consumer;
+
 import static at.gv.zustellung.msg.xsd.DeliveryNotificationACKType.deliveryNotificationACKTypeBuilder;
 import static at.gv.zustellung.msg.xsd.DeliveryRequestStatusACKType.deliveryRequestStatusACKTypeBuilder;
 import static at.gv.zustellung.msg.xsd.GetVersionResponse.getVersionResponseBuilder;
@@ -20,12 +21,12 @@ import static java.util.concurrent.CompletableFuture.runAsync;
 public class MsgService implements Zuse2AppPort {
 
     private final DeliveryRepository repository;
-    private final MsgResponseHandler handler;
+    private final Consumer<String> backend;
 
     @Autowired
-    public MsgService(DeliveryRepository repository, MsgResponseHandler handler) {
+    public MsgService(DeliveryRepository repository, Consumer<String> msgResponseBackend) {
         this.repository = repository;
-        this.handler = handler;
+        this.backend = msgResponseBackend;
     }
 
     @Override
@@ -59,7 +60,7 @@ public class MsgService implements Zuse2AppPort {
 
     private void sendToWork(MsgResponse response) {
         runAsync(() -> repository.store(response))
-            .thenRunAsync(() -> handler.handle(response.getResponseID()));
+            .thenRunAsync(() -> backend.accept(response.getResponseID()));
     }
 
     private DeliveryNotificationACKType notificationAck(String appDeliveryID, String zsDeliveryID) {
diff --git a/src/main/java/at/gv/egiz/moazs/service/MzsService.java b/src/main/java/at/gv/egiz/moazs/service/MzsService.java
index 2755a37..c8c0878 100644
--- a/src/main/java/at/gv/egiz/moazs/service/MzsService.java
+++ b/src/main/java/at/gv/egiz/moazs/service/MzsService.java
@@ -1,7 +1,6 @@
 package at.gv.egiz.moazs.service;
 
 import at.gv.egiz.moazs.preprocess.DeliveryRequestAugmenter;
-import at.gv.egiz.moazs.process.DeliveryPipeline;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.Msg2MzsConverter;
 import at.gv.egiz.moazs.client.MzsClient;
@@ -19,6 +18,7 @@ import org.springframework.stereotype.Service;
 import javax.jws.WebParam;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.function.Consumer;
 
 import static at.gv.egiz.moazs.MoaZSException.moaZSException;
 import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
@@ -36,16 +36,16 @@ public class MzsService implements App2MzsPortType {
     private static final int TIMEOUT_FOR_ANWSER = 10;
 
     private final DeliveryRepository repository;
-    private final DeliveryPipeline pipeline;
+    private final Consumer<String> backend;
     private final MzsClient appClient;
     private final DeliveryRequestAugmenter augmenter;
     private final Msg2MzsConverter converter;
 
     @Autowired
-    public MzsService(DeliveryRepository repository, DeliveryPipeline pipeline, MzsClient appClient,
+    public MzsService(DeliveryRepository repository, Consumer<String> deliveryRequestBackend, MzsClient appClient,
                       DeliveryRequestAugmenter augmenter, Msg2MzsConverter converter) {
         this.repository = repository;
-        this.pipeline = pipeline;
+        this.backend = deliveryRequestBackend;
         this.appClient = appClient;
         this.augmenter = augmenter;
         this.converter = converter;
@@ -87,7 +87,7 @@ public class MzsService implements App2MzsPortType {
         logger.info("Receive request with appDeliveryID = {}.", appDeliveryID);
 
         repository.store(deliveryRequest);
-        pipeline.processRequest(appDeliveryID);
+        backend.accept(appDeliveryID);
 
         var statusId = RequestStatusResponse.getResponseID(appDeliveryID);
         var response = repository.retrieveResponse(statusId)
diff --git a/src/main/java/at/gv/egiz/moazs/verify/SignatureVerifier.java b/src/main/java/at/gv/egiz/moazs/verify/SignatureVerifier.java
deleted file mode 100644
index a31c4cf..0000000
--- a/src/main/java/at/gv/egiz/moazs/verify/SignatureVerifier.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package at.gv.egiz.moazs.verify;
-
-@FunctionalInterface
-public interface SignatureVerifier {
-
-    /**
-     * Verifies the signature of a signed XML document. Throws a at.gv.egiz.moazs.MoaZSException exception
-     * if the validation fails.
-     * @param signedXMLdocument
-     * @throws at.gv.egiz.moazs.MoaZSException
-     */
-    void verify(byte[] signedXMLdocument);
-}
diff --git a/src/test/java/at/gv/egiz/moazs/SingleThreadedDeliveryPipelineTest.java b/src/test/java/at/gv/egiz/moazs/DeliveryRequestBackendTest.java
index e245eb1..ed63489 100644
--- a/src/test/java/at/gv/egiz/moazs/SingleThreadedDeliveryPipelineTest.java
+++ b/src/test/java/at/gv/egiz/moazs/DeliveryRequestBackendTest.java
@@ -1,13 +1,12 @@
 package at.gv.egiz.moazs;
 
-import at.gv.egiz.moazs.process.DeliveryPipeline;
-import at.gv.egiz.moazs.process.SingleThreadedDeliveryPipeline;
-import at.gv.egiz.moazs.client.TnvzHelper;
-import at.gv.egiz.moazs.scheme.*;
 import at.gv.egiz.moazs.client.ClientFactory;
+import at.gv.egiz.moazs.client.TnvzHelper;
+import at.gv.egiz.moazs.backend.DeliveryRequestBackend;
+import at.gv.egiz.moazs.backend.SignatureVerifier;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.repository.InMemoryDeliveryRepository;
-import at.gv.egiz.moazs.verify.MoaSPSSSignatureVerifier;
+import at.gv.egiz.moazs.scheme.Mzs2MsgConverter;
 import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
 import at.gv.zustellung.msg.xsd.App2ZusePort;
 import at.gv.zustellung.msg.xsd.DeliveryRequestStatusType;
@@ -35,7 +34,7 @@ import static org.mockito.ArgumentMatchers.same;
 import static org.mockito.Mockito.*;
 
 @RunWith(MockitoJUnitRunner.class)
-public class SingleThreadedDeliveryPipelineTest {
+public class DeliveryRequestBackendTest {
 
     private DeliveryRepository repository = new InMemoryDeliveryRepository(100);
 
@@ -55,14 +54,14 @@ public class SingleThreadedDeliveryPipelineTest {
     private Mzs2MsgConverter converter;
 
     @Mock
-    private MoaSPSSSignatureVerifier verifier;
+    private SignatureVerifier verifier;
 
 
-    private DeliveryPipeline pipeline;
+    private DeliveryRequestBackend pipeline;
 
     @Before
     public void setup() {
-        pipeline = new SingleThreadedDeliveryPipeline(
+        pipeline = new DeliveryRequestBackend(
                 repository,
                 tnvzHelper,
                 converter,
@@ -75,7 +74,7 @@ public class SingleThreadedDeliveryPipelineTest {
         var appDeliveryID = "no-tnvz-request";
         var expectedStatus = setupMocks(appDeliveryID, false);
 
-        pipeline.processRequest(appDeliveryID);
+        pipeline.accept(appDeliveryID);
 
         verifyZeroInteractions(tnvzHelper);
         var response = repository.retrieveResponse(getResponseID(appDeliveryID)).get();
@@ -91,7 +90,7 @@ public class SingleThreadedDeliveryPipelineTest {
         when(tnvzHelper.performQueryPersonRequest(any(), any(), any()))
                 .thenThrow(buildMzsException("400", appDeliveryID));
 
-        pipeline.processRequest(appDeliveryID);
+        pipeline.accept(appDeliveryID);
 
         var responseID = getResponseID(appDeliveryID);
         var response = repository.retrieveResponse(responseID).get();
@@ -108,7 +107,7 @@ public class SingleThreadedDeliveryPipelineTest {
         var appDeliveryID = "tnvz-request";
         var expectedStatus = setupMocks(appDeliveryID, true);
 
-        pipeline.processRequest(appDeliveryID);
+        pipeline.accept(appDeliveryID);
         var response = repository.retrieveResponse(getResponseID(appDeliveryID)).get();
         var actualStatus = (DeliveryRequestStatusType) response.getResponse();
 
@@ -119,9 +118,9 @@ public class SingleThreadedDeliveryPipelineTest {
     public void rejectInvalidSignature() {
         var appDeliveryID = "invalid-signature";
         setupMocks(appDeliveryID, true);
-        doThrow(moaZSException("Signature Invalid!")).when(verifier).verify(any());
+        doThrow(moaZSException("Signature Invalid!")).when(verifier).accept(any());
 
-        pipeline.processRequest(appDeliveryID);
+        pipeline.accept(appDeliveryID);
         var response = repository.retrieveResponse(getResponseID(appDeliveryID)).get();
         var status = (DeliveryRequestStatusType) response.getResponse();
         var actualCode = status.getError().getErrorInfo().getCode();
diff --git a/src/test/java/at/gv/egiz/moazs/ITMoaSPSSSignatureVerifierTest.java b/src/test/java/at/gv/egiz/moazs/ITMoaSPSSSignatureVerifierTest.java
index 2c6b978..34f4e1b 100644
--- a/src/test/java/at/gv/egiz/moazs/ITMoaSPSSSignatureVerifierTest.java
+++ b/src/test/java/at/gv/egiz/moazs/ITMoaSPSSSignatureVerifierTest.java
@@ -1,8 +1,7 @@
 package at.gv.egiz.moazs;
 
 import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.ISignatureVerificationService;
-import at.gv.egiz.moazs.verify.MoaSPSSSignatureVerifier;
-import at.gv.egiz.moazs.verify.SignatureVerifier;
+import at.gv.egiz.moazs.backend.SignatureVerifier;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -27,7 +26,7 @@ import java.nio.file.Files;
 
         @Bean
         public SignatureVerifier verifier(@Autowired ISignatureVerificationService service){
-            return new MoaSPSSSignatureVerifier(service, "test-trust-profile", true);
+            return new SignatureVerifier(service, "test-trust-profile", true);
         }
 
     }
@@ -41,7 +40,7 @@ import java.nio.file.Files;
         var path = resourcesPath + "valid-signed-delivery-response.xml";
         var signature = Files.readAllBytes(new File(path).toPath());
 
-        verifier.verify(signature);
+        verifier.accept(signature);
     }
 
     @Test(expected = MoaZSException.class)
@@ -50,7 +49,7 @@ import java.nio.file.Files;
         var path = resourcesPath + "invalid-signed-delivery-response.xml";
         var signature = Files.readAllBytes(new File(path).toPath());
 
-        verifier.verify(signature);
+        verifier.accept(signature);
     }
 
 }
diff --git a/src/test/java/at/gv/egiz/moazs/ITMzsServiceTest.java b/src/test/java/at/gv/egiz/moazs/ITMzsServiceTest.java
index a93c720..e9b4f70 100644
--- a/src/test/java/at/gv/egiz/moazs/ITMzsServiceTest.java
+++ b/src/test/java/at/gv/egiz/moazs/ITMzsServiceTest.java
@@ -1,12 +1,9 @@
 package at.gv.egiz.moazs;
 
-import at.gv.egiz.moazs.process.DeliveryPipeline;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.RequestStatusResponse;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
@@ -25,6 +22,7 @@ import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.nio.file.Paths;
 import java.util.GregorianCalendar;
+import java.util.function.Consumer;
 
 import static at.gv.zustellung.msg.xsd.DeliveryRequestStatusType.Success.successBuilder;
 import static at.gv.zustellung.msg.xsd.DeliveryRequestStatusType.deliveryRequestStatusTypeBuilder;
@@ -40,8 +38,6 @@ public class ITMzsServiceTest {
 
     private final String basePath = "src/test/resources/at/gv/egiz/moazs/ITMzsServiceTest/";
 
-    private final static Logger logger = LoggerFactory.getLogger(ITMzsServiceTest.class);
-
     @TestConfiguration
     public static class TestConfig {
 
@@ -50,7 +46,7 @@ public class ITMzsServiceTest {
 
         @Bean
         @Primary
-        public DeliveryPipeline deliveryPipelineThatAlwaysSucceeds() {
+        public Consumer<String> deliveryPipelineThatAlwaysSucceeds() {
             return appDeliveryId -> {
 
                 var success = successBuilder()
diff --git a/src/test/java/at/gv/egiz/moazs/SaveResponseToFileSinkTest.java b/src/test/java/at/gv/egiz/moazs/SaveResponseToFileSinkTest.java
index ca501c8..9ddd37e 100644
--- a/src/test/java/at/gv/egiz/moazs/SaveResponseToFileSinkTest.java
+++ b/src/test/java/at/gv/egiz/moazs/SaveResponseToFileSinkTest.java
@@ -1,6 +1,6 @@
 package at.gv.egiz.moazs;
 
-import at.gv.egiz.moazs.process.SaveResponseToFileSink;
+import at.gv.egiz.moazs.backend.SaveResponseToFileSink;
 import at.gv.egiz.moazs.repository.DeliveryRepository;
 import at.gv.egiz.moazs.scheme.Marshaller;
 import at.gv.egiz.moazs.scheme.RequestStatusResponse;
@@ -63,7 +63,7 @@ public class SaveResponseToFileSinkTest {
         var fileContent = "<xml>some content</xml>";
         var status = setupMocks(fileContent);
 
-        sink.handle(status)
+        sink.apply(status)
                 .thenRun(() -> assertFilesCreatedAndContentMatches(fileContent));
     }