Issue #106: Added method to get optional correlation ID from a specif…

…ied Signal. Signed-off-by: Juergen Fickel <juergen.fickel@bosch.io>
eclipse-ditto · Nov 11, 2021 · ef4f8f0 · ef4f8f0
1 parent d842488
commit ef4f8f0
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Showing 2 changed files with 40 additions and 1 deletion.
diff --git a/...signal/src/main/java/org/eclipse/ditto/internal/models/signal/SignalInformationPoint.java b/...signal/src/main/java/org/eclipse/ditto/internal/models/signal/SignalInformationPoint.java
@@ -38,7 +38,7 @@ public final class SignalInformationPoint {
     private static final String CHANNEL_LIVE_VALUE = "live";
 
     private SignalInformationPoint() {
-        throw new AssertionError("nope");
+        throw new AssertionError();
     }
 
     /**
@@ -167,4 +167,21 @@ public static Optional<EntityId> getEntityId(@Nullable final Signal<?> signal) {
         return result;
     }
 
+    /**
+     * Returns the optional correlation ID of the specified {@code Signal} argument's headers.
+     *
+     * @param signal the signal to get the optional correlation ID from.
+     * @return the optional correlation ID. The optional is empty if {@code signal} is {@code null}.
+     */
+    public static Optional<String> getCorrelationId(@Nullable final Signal<?> signal) {
+        final Optional<String> result;
+        if (null != signal) {
+            final var signalDittoHeaders = signal.getDittoHeaders();
+            result = signalDittoHeaders.getCorrelationId();
+        } else {
+            result = Optional.empty();
+        }
+        return result;
+    }
+
 }
diff --git a/...al/src/test/java/org/eclipse/ditto/internal/models/signal/SignalInformationPointTest.java b/...al/src/test/java/org/eclipse/ditto/internal/models/signal/SignalInformationPointTest.java
@@ -20,6 +20,7 @@
 import org.eclipse.ditto.base.model.correlationid.TestNameCorrelationId;
 import org.eclipse.ditto.base.model.headers.DittoHeaders;
 import org.eclipse.ditto.base.model.headers.WithDittoHeaders;
+import org.eclipse.ditto.base.model.signals.Signal;
 import org.eclipse.ditto.base.model.signals.SignalWithEntityId;
 import org.eclipse.ditto.internal.models.signal.common.SignalInterfaceImplementations;
 import org.eclipse.ditto.messages.model.signals.commands.MessageCommand;
@@ -294,6 +295,27 @@ public void getEntityIdForSignalWithoutEntityIdReturnsEmptyOptional() {
         assertThat(SignalInformationPoint.getEntityId(signal)).isEmpty();
     }
 
+    @Test
+    public void getCorrelationIdFromNullSignalReturnsEmptyOptional() {
+        assertThat(SignalInformationPoint.getCorrelationId(null)).isEmpty();
+    }
+
+    @Test
+    public void getCorrelationIdFromSignalWithHeadersWithoutCorrelationIdReturnsEmptyCorrelationId() {
+        final Signal<?> signal = Mockito.mock(Signal.class);
+        Mockito.when(signal.getDittoHeaders()).thenReturn(DittoHeaders.empty());
+
+        assertThat(SignalInformationPoint.getCorrelationId(null)).isEmpty();
+    }
+
+    @Test
+    public void getCorrelationIdFromSignalWithCorrelationIdInHeadersReturnsThoseCorrelationId() {
+        final Signal<?> signal = Mockito.mock(Signal.class);
+        Mockito.when(signal.getDittoHeaders()).thenReturn(dittoHeaders);
+
+        assertThat(SignalInformationPoint.getCorrelationId(signal)).isEqualTo(dittoHeaders.getCorrelationId());
+    }
+
     private static String getSimpleClassName(final Object o) {
         final var oClass = o.getClass();
         return oClass.getSimpleName();