Simplify class hierarchy

CHANGELOG.md

@@ -22,6 +22,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - Replace `SdmxWebConnection#ping()` with `SdmxConnection#testConnection()`
 - Refactor data query API [#218](https://github.com/nbbrd/sdmx-dl/issues/218)
 - Replace `SdmxConnection#isDetailSupported()` with a more general solution [#89](https://github.com/nbbrd/sdmx-dl/issues/89)
+- Simplify class hierarchy [#222](https://github.com/nbbrd/sdmx-dl/issues/222)
 
 ### Fixed
 

sdmx-dl-api/src/main/java/internal/sdmxdl/web/spi/FailsafeWebConnection.java → sdmx-dl-api/src/main/java/internal/sdmxdl/web/spi/FailsafeConnection.java

@@ -19,7 +19,6 @@
 import lombok.AccessLevel;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import sdmxdl.*;
-import sdmxdl.web.SdmxWebConnection;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -34,16 +33,16 @@
  */
 @SuppressWarnings("ConstantConditions")
 @lombok.AllArgsConstructor(access = AccessLevel.PACKAGE)
-final class FailsafeWebConnection implements SdmxWebConnection {
+final class FailsafeConnection implements SdmxConnection {
 
-    static SdmxWebConnection wrap(SdmxWebConnection obj) {
-        if (obj instanceof FailsafeWebConnection) return obj;
+    static SdmxConnection wrap(SdmxConnection obj) {
+        if (obj instanceof FailsafeConnection) return obj;
         FailsafeLogging logging = FailsafeLogging.of(FailsafeWebDriver.class);
-        return new FailsafeWebConnection(obj, logging::logUnexpectedError, logging::logUnexpectedNull);
+        return new FailsafeConnection(obj, logging::logUnexpectedError, logging::logUnexpectedNull);
     }
 
     @lombok.NonNull
-    private final SdmxWebConnection delegate;
+    private final SdmxConnection delegate;
 
     @lombok.NonNull
     private final BiConsumer<? super String, ? super RuntimeException> onUnexpectedError;
@@ -60,23 +59,6 @@ public void testConnection() throws IOException {
         }
     }
 
-    @Override
-    public String getDriver() throws IOException {
-        String result;
-
-        try {
-            result = delegate.getDriver();
-        } catch (RuntimeException ex) {
-            throw unexpectedError(ex, "while getting driver");
-        }
-
-        if (result == null) {
-            throw unexpectedNull("driver");
-        }
-
-        return result;
-    }
-
     @Override
     public Collection<Dataflow> getFlows() throws IOException {
         Collection<Dataflow> result;

sdmx-dl-api/src/main/java/internal/sdmxdl/web/spi/FailsafeWebDriver.java

@@ -17,7 +17,7 @@
 package internal.sdmxdl.web.spi;
 
 import lombok.AccessLevel;
-import sdmxdl.web.SdmxWebConnection;
+import sdmxdl.SdmxConnection;
 import sdmxdl.web.SdmxWebSource;
 import sdmxdl.web.spi.SdmxWebContext;
 import sdmxdl.web.spi.SdmxWebDriver;
@@ -90,11 +90,11 @@ public boolean isAvailable() {
     }
 
     @Override
-    public SdmxWebConnection connect(SdmxWebSource source, SdmxWebContext context) throws IOException, IllegalArgumentException {
+    public SdmxConnection connect(SdmxWebSource source, SdmxWebContext context) throws IOException, IllegalArgumentException {
         Objects.requireNonNull(source);
         Objects.requireNonNull(context);
 
-        SdmxWebConnection result;
+        SdmxConnection result;
 
         try {
             result = delegate.connect(source, context);
@@ -108,7 +108,7 @@ public SdmxWebConnection connect(SdmxWebSource source, SdmxWebContext context) t
             throw newUnexpectedNull("null connection");
         }
 
-        return FailsafeWebConnection.wrap(result);
+        return FailsafeConnection.wrap(result);
     }
 
     @Override

sdmx-dl-api/src/main/java/sdmxdl/SdmxManager.java

@@ -26,6 +26,7 @@
 
 import java.io.IOException;
 import java.util.List;
+import java.util.function.BiConsumer;
 
 /**
  * @author Philippe Charles
@@ -35,13 +36,20 @@
         SdmxWebManager.class
 })
 @ThreadSafe
-public abstract class SdmxManager<SOURCE> {
+public abstract class SdmxManager<SOURCE extends SdmxSource> {
 
     public abstract @NonNull SdmxConnection getConnection(@NonNull SOURCE source) throws IOException;
 
     public abstract @NonNull LanguagePriorityList getLanguages();
 
     public abstract @NonNull SdmxCache getCache();
 
+    public abstract @NonNull BiConsumer<? super SOURCE, ? super String> getEventListener();
+
     public abstract @NonNull List<SdmxDialect> getDialects();
+
+    public static final BiConsumer<SdmxSource, String> NO_OP_EVENT_LISTENER = SdmxManager::doNothing;
+
+    private static void doNothing(SdmxSource source, String message) {
+    }
 }

sdmx-dl-api/src/main/java/sdmxdl/SdmxSource.java

@@ -0,0 +1,12 @@
+package sdmxdl;
+
+import nbbrd.design.SealedType;
+import sdmxdl.file.SdmxFileSource;
+import sdmxdl.web.SdmxWebSource;
+
+@SealedType({
+        SdmxFileSource.class,
+        SdmxWebSource.class
+})
+public abstract class SdmxSource {
+}

sdmx-dl-api/src/main/java/sdmxdl/file/SdmxFileManager.java

@@ -19,6 +19,7 @@
 import lombok.AccessLevel;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import sdmxdl.LanguagePriorityList;
+import sdmxdl.SdmxConnection;
 import sdmxdl.SdmxManager;
 import sdmxdl.ext.SdmxCache;
 import sdmxdl.ext.spi.SdmxDialect;
@@ -31,6 +32,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.function.BiConsumer;
 
 /**
  * @author Philippe Charles
@@ -58,7 +60,7 @@ public static SdmxFileManager ofServiceLoader() {
 
     @lombok.NonNull
     @lombok.Builder.Default
-    SdmxFileListener eventListener = SdmxFileListener.getDefault();
+    BiConsumer<? super SdmxFileSource, ? super String> eventListener = NO_OP_EVENT_LISTENER;
 
     @lombok.NonNull
     @lombok.Singular
@@ -73,7 +75,7 @@ public static SdmxFileManager ofServiceLoader() {
     SdmxFileContext context = initContext();
 
     @Override
-    public @NonNull SdmxFileConnection getConnection(@NonNull SdmxFileSource source) throws IOException {
+    public @NonNull SdmxConnection getConnection(@NonNull SdmxFileSource source) throws IOException {
         Objects.requireNonNull(source);
 
         SdmxFileReader reader = lookupReader(source)

sdmx-dl-api/src/main/java/sdmxdl/file/SdmxFileSource.java

@@ -19,6 +19,7 @@
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import sdmxdl.DataflowRef;
+import sdmxdl.SdmxSource;
 
 import java.io.File;
 
@@ -27,7 +28,8 @@
  */
 @lombok.Value
 @lombok.Builder(toBuilder = true)
-public class SdmxFileSource {
+@lombok.EqualsAndHashCode(callSuper = false)
+public class SdmxFileSource extends SdmxSource {
 
     @lombok.NonNull
     File data;