Issue #561: Added revoked subjects to DittoHeaders.

Signed-off-by: Juergen Fickel <juergen.fickel@bosch-si.com>

model/base/src/main/java/org/eclipse/ditto/model/base/headers/AbstractDittoHeaders.java

@@ -107,12 +107,21 @@ public AuthorizationContext getAuthorizationContext() {
 
     @Override
     public Set<String> getReadSubjects() {
-        final JsonArray jsonValueArray = getJsonArrayForDefinition(DittoHeaderDefinition.READ_SUBJECTS);
+        return getSubjects(DittoHeaderDefinition.READ_SUBJECTS);
+    }
+
+    private Set<String> getSubjects(final HeaderDefinition headerDefinition) {
+        final JsonArray jsonValueArray = getJsonArrayForDefinition(headerDefinition);
         return jsonValueArray.stream()
                 .map(JsonValue::asString)
                 .collect(Collectors.toSet());
     }
 
+    @Override
+    public Set<String> getRevokedSubjects() {
+        return getSubjects(DittoHeaderDefinition.REVOKED_SUBJECTS);
+    }
+
     @Override
     public Optional<String> getChannel() {
         return getStringForDefinition(DittoHeaderDefinition.CHANNEL);

model/base/src/main/java/org/eclipse/ditto/model/base/headers/AbstractDittoHeadersBuilder.java

@@ -196,6 +196,12 @@ public S readSubjects(final Collection<String> readSubjects) {
         return myself;
     }
 
+    @Override
+    public S revokedSubjects(final Collection<String> revokedSubjects) {
+        putStringCollection(DittoHeaderDefinition.REVOKED_SUBJECTS, revokedSubjects);
+        return myself;
+    }
+
     @Override
     public S channel(@Nullable final CharSequence channel) {
         putCharSequence(DittoHeaderDefinition.CHANNEL, channel);

model/base/src/main/java/org/eclipse/ditto/model/base/headers/DittoHeaderDefinition.java

@@ -77,6 +77,16 @@ public enum DittoHeaderDefinition implements HeaderDefinition {
      */
     READ_SUBJECTS("ditto-read-subjects", JsonArray.class, false, false),
 
+    /**
+     * Header definition for revoked subjects value.
+     *
+     * <p>
+     * Key: {@code "revoked-subjects"}, Java type: {@link JsonArray}.
+     * </p>
+     * @since 1.1.0
+     */
+    REVOKED_SUBJECTS("ditto-revoked-subjects", JsonArray.class, false, false),
+
     /**
      * Header definition for a signal's content-type.
      * <p>

model/base/src/main/java/org/eclipse/ditto/model/base/headers/DittoHeaders.java

@@ -168,6 +168,16 @@ default DittoHeadersBuilder toBuilder() {
      */
     Set<String> getReadSubjects();
 
+    /**
+     * Returns the authorization subjects with explicitly revoked "READ" permissions for the key in the map defining a
+     * pointer in the Thing.
+     * Changes on the returned Set are not reflected back to this headers object.
+     *
+     * @return the revoked subjects for pointers in the Thing.
+     * @since 1.1.0
+     */
+    Set<String> getRevokedSubjects();
+
     /**
      * Returns the channel (twin/live) on which a Signal/Exception was sent/occurred.
      *

model/base/src/main/java/org/eclipse/ditto/model/base/headers/DittoHeadersBuilder.java

@@ -97,6 +97,16 @@ default B randomCorrelationId() {
      */
     B readSubjects(Collection<String> readSubjects);
 
+    /**
+     * Sets the revokedSubjects value.
+     *
+     * @param revokedSubjects the revokedSubjects value to be set.
+     * @return this builder for Method Chaining.
+     * @throws NullPointerException if {@code revokedSubjects} is {@code null}.
+     * @since 1.1.0
+     */
+    B revokedSubjects(Collection<String> revokedSubjects);
+
     /**
      * Sets the specified String as channel of the Signal/Exception.
      *

model/base/src/test/java/org/eclipse/ditto/model/base/headers/ImmutableDittoHeadersTest.java

@@ -20,13 +20,13 @@
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import org.assertj.core.util.Lists;
 import org.assertj.core.util.Maps;
 import org.eclipse.ditto.json.JsonArray;
 import org.eclipse.ditto.json.JsonArrayBuilder;
@@ -60,7 +60,9 @@ public final class ImmutableDittoHeadersTest {
     private static final EntityTagMatchers KNOWN_IF_NONE_MATCH =
             EntityTagMatchers.fromCommaSeparatedString("\"notOneValue\",\"notAnotherValue\"");
     private static final EntityTag KNOWN_ETAG = EntityTag.fromString("\"-12124212\"");
-    private static final Collection<String> KNOWN_READ_SUBJECTS = Collections.singleton(KNOWN_READ_SUBJECT);
+    private static final Collection<String> KNOWN_READ_SUBJECTS = Lists.list(KNOWN_READ_SUBJECT);
+    private static final Collection<String> KNOWN_REVOKED_SUBJECTS =
+            Lists.list("knownRevokedSubject1", "knownRevokedSubject2");
     private static final String KNOWN_CONTENT_TYPE = "application/json";
     private static final String KNOWN_ORIGIN = "knownOrigin";
     private static final String KNOWN_REPLY_TARGET = "5";
@@ -88,6 +90,7 @@ public void settingAllKnownHeadersWorksAsExpected() {
                 .authorizationSubjects(AUTH_SUBJECTS)
                 .correlationId(KNOWN_CORRELATION_ID)
                 .readSubjects(KNOWN_READ_SUBJECTS)
+                .revokedSubjects(KNOWN_REVOKED_SUBJECTS)
                 .responseRequired(KNOWN_RESPONSE_REQUIRED)
                 .dryRun(false)
                 .schemaVersion(KNOWN_SCHEMA_VERSION)
@@ -170,7 +173,14 @@ public void getAuthorizationContextReturnsExpected() {
     public void getReadSubjectsReturnsExpected() {
         final DittoHeaders underTest = DittoHeaders.newBuilder().readSubjects(KNOWN_READ_SUBJECTS).build();
 
-        assertThat(underTest.getReadSubjects()).isEqualTo(KNOWN_READ_SUBJECTS);
+        assertThat(underTest.getReadSubjects()).containsExactlyInAnyOrderElementsOf(KNOWN_READ_SUBJECTS);
+    }
+
+    @Test
+    public void getRevokedSubjectsReturnsExpected() {
+        final DittoHeaders underTest = DittoHeaders.newBuilder().revokedSubjects(KNOWN_REVOKED_SUBJECTS).build();
+
+        assertThat(underTest.getRevokedSubjects()).containsExactlyInAnyOrderElementsOf(KNOWN_REVOKED_SUBJECTS);
     }
 
     @Test
@@ -211,6 +221,7 @@ public void toJsonReturnsExpected() {
                 .set(DittoHeaderDefinition.RESPONSE_REQUIRED.getKey(), KNOWN_RESPONSE_REQUIRED)
                 .set(DittoHeaderDefinition.DRY_RUN.getKey(), false)
                 .set(DittoHeaderDefinition.READ_SUBJECTS.getKey(), toJsonArray(KNOWN_READ_SUBJECTS))
+                .set(DittoHeaderDefinition.REVOKED_SUBJECTS.getKey(), toJsonArray(KNOWN_REVOKED_SUBJECTS))
                 .set(DittoHeaderDefinition.IF_MATCH.getKey(), KNOWN_IF_MATCH.toString())
                 .set(DittoHeaderDefinition.IF_NONE_MATCH.getKey(), KNOWN_IF_NONE_MATCH.toString())
                 .set(DittoHeaderDefinition.ETAG.getKey(), KNOWN_ETAG.toString())
@@ -317,7 +328,7 @@ public void entriesSizeIsGreaterThanZeroIfHeadersAreNotEmpty() {
 
     @Test
     public void entriesSizeIsNotGreaterThanZeroIfHeadersAreEmpty() {
-        final ImmutableDittoHeaders underTest = ImmutableDittoHeaders.of(Collections.emptyMap());
+        final ImmutableDittoHeaders underTest = ImmutableDittoHeaders.of(new HashMap());
 
         assertThat(underTest.isEntriesSizeGreaterThan(0)).isFalse();
     }
@@ -371,6 +382,7 @@ private static Map<String, String> createMapContainingAllKnownHeaders() {
         result.put(DittoHeaderDefinition.RESPONSE_REQUIRED.getKey(), String.valueOf(KNOWN_RESPONSE_REQUIRED));
         result.put(DittoHeaderDefinition.DRY_RUN.getKey(), String.valueOf(false));
         result.put(DittoHeaderDefinition.READ_SUBJECTS.getKey(), toJsonArray(KNOWN_READ_SUBJECTS).toString());
+        result.put(DittoHeaderDefinition.REVOKED_SUBJECTS.getKey(), toJsonArray(KNOWN_REVOKED_SUBJECTS).toString());
         result.put(DittoHeaderDefinition.IF_MATCH.getKey(), KNOWN_IF_MATCH.toString());
         result.put(DittoHeaderDefinition.IF_NONE_MATCH.getKey(), KNOWN_IF_NONE_MATCH.toString());
         result.put(DittoHeaderDefinition.ETAG.getKey(), KNOWN_ETAG.toString());