DBZ-7416 Fix duplicate SMTs sometimes returned by Kafka Connect. Moved deduplication from Map to LinkedHashSet.

closes https://issues.redhat.com/browse/DBZ-7416

debezium-connect-rest-extension/src/main/java/io/debezium/kcrestextension/DebeziumResource.java

@@ -11,8 +11,8 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -68,7 +68,7 @@ public class DebeziumResource {
     private final Boolean isTopicCreationEnabled;
     private List<TransformDefinition> transforms = null;
     private List<PredicateDefinition> predicates = null;
-    private List<ConnectorDescriptor> availableConnectorPlugins = null;
+    private Set<ConnectorDescriptor> availableConnectorPlugins = null;
 
     private static final Pattern VERSION_PATTERN = Pattern
             .compile("([1-9][0-9]*(?:(?:\\.0)*\\.[1-9][0-9]*)*)(?:-([a-zA-Z0-9]+))?(?:(\\+)(0|[1-9][0-9]*)?)?(?:-([-a-zA-Z0-9.]+))?");
@@ -93,20 +93,20 @@ else if (m.lookingAt()) {
         throw new IllegalArgumentException("Invalid version string: \"" + version + "\"");
     }
 
-    private static <T> void addConnectorPlugins(Map<String, ConnectorDescriptor> connectorPlugins, Collection<PluginDesc<T>> plugins) {
+    private static <T> void addConnectorPlugins(Set<ConnectorDescriptor> connectorPlugins, Collection<PluginDesc<T>> plugins) {
         plugins.stream()
                 .filter(p -> SUPPORTED_CONNECTORS.contains(p.pluginClass().getName()))
-                .forEach(p -> connectorPlugins.put(p.pluginClass().getName() + "#" + p.version(), new ConnectorDescriptor(p.pluginClass().getName(), p.version())));
+                .forEach(p -> connectorPlugins.add(new ConnectorDescriptor(p.pluginClass().getName(), p.version())));
     }
 
     private synchronized void initConnectorPlugins() {
         if (null == this.availableConnectorPlugins || this.availableConnectorPlugins.isEmpty()) {
             // TODO: improve once plugins are allowed to be added/removed during runtime by Kafka Connect, @see org.apache.kafka.connect.runtime.rest.resources.ConnectorPluginsResource
-            final Map<String, ConnectorDescriptor> connectorPlugins = new HashMap<>();
+            final Set<ConnectorDescriptor> connectorPlugins = new LinkedHashSet<>();
             Herder herder = getHerder();
             addConnectorPlugins(connectorPlugins, herder.plugins().sinkConnectors());
             addConnectorPlugins(connectorPlugins, herder.plugins().sourceConnectors());
-            this.availableConnectorPlugins = Collections.unmodifiableList(new ArrayList<>(connectorPlugins.values()));
+            this.availableConnectorPlugins = Collections.unmodifiableSet(connectorPlugins);
         }
     }
 
@@ -165,7 +165,7 @@ private synchronized Herder getHerder() {
     @GET
     @Path(CONNECTOR_PLUGINS_ENDPOINT)
     @Produces(MediaType.APPLICATION_JSON)
-    public List<ConnectorDescriptor> availableDebeziumConnectors() {
+    public Set<ConnectorDescriptor> availableDebeziumConnectors() {
         initConnectorPlugins();
         return this.availableConnectorPlugins;
     }

debezium-connector-mongodb/src/main/java/io/debezium/connector/mongodb/metadata/MongoDbConnectorMetadata.java

@@ -16,7 +16,7 @@ public class MongoDbConnectorMetadata implements ConnectorMetadata {
 
     @Override
     public ConnectorDescriptor getConnectorDescriptor() {
-        return new ConnectorDescriptor("mongodb", "Debezium MongoDB Connector", MongoDbConnector.class.getName(), Module.version());
+        return new ConnectorDescriptor(MongoDbConnector.class.getName(), Module.version());
     }
 
     @Override

debezium-connector-mysql/src/main/java/io/debezium/connector/mysql/metadata/MySqlConnectorMetadata.java

@@ -16,7 +16,7 @@ public class MySqlConnectorMetadata implements ConnectorMetadata {
 
     @Override
     public ConnectorDescriptor getConnectorDescriptor() {
-        return new ConnectorDescriptor("mysql", "Debezium MySQL Connector", MySqlConnector.class.getName(), Module.version());
+        return new ConnectorDescriptor(MySqlConnector.class.getName(), Module.version());
     }
 
     @Override

debezium-connector-oracle/src/main/java/io/debezium/connector/oracle/metadata/OracleConnectorMetadata.java

@@ -16,7 +16,7 @@ public class OracleConnectorMetadata implements ConnectorMetadata {
 
     @Override
     public ConnectorDescriptor getConnectorDescriptor() {
-        return new ConnectorDescriptor("oracle", "Debezium Oracle Connector", OracleConnector.class.getName(), Module.version());
+        return new ConnectorDescriptor(OracleConnector.class.getName(), Module.version());
     }
 
     @Override

debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/metadata/PostgresConnectorMetadata.java

@@ -16,7 +16,7 @@ public class PostgresConnectorMetadata implements ConnectorMetadata {
 
     @Override
     public ConnectorDescriptor getConnectorDescriptor() {
-        return new ConnectorDescriptor("postgres", "Debezium PostgreSQL Connector", PostgresConnector.class.getName(), Module.version());
+        return new ConnectorDescriptor(PostgresConnector.class.getName(), Module.version());
     }
 
     @Override

debezium-connector-sqlserver/src/main/java/io/debezium/connector/sqlserver/metadata/SqlServerConnectorMetadata.java

@@ -16,7 +16,7 @@ public class SqlServerConnectorMetadata implements ConnectorMetadata {
 
     @Override
     public ConnectorDescriptor getConnectorDescriptor() {
-        return new ConnectorDescriptor("sqlserver", "Debezium SQLServer Connector", SqlServerConnector.class.getName(), Module.version());
+        return new ConnectorDescriptor(SqlServerConnector.class.getName(), Module.version());
     }
 
     @Override

debezium-core/src/main/java/io/debezium/metadata/ConnectorDescriptor.java

@@ -5,6 +5,8 @@
  */
 package io.debezium.metadata;
 
+import java.util.Objects;
+
 public class ConnectorDescriptor {
 
     private final String id;
@@ -12,7 +14,7 @@ public class ConnectorDescriptor {
     private final String className;
     private final String version;
 
-    public ConnectorDescriptor(String id, String displayName, String className, String version) {
+    private ConnectorDescriptor(String id, String displayName, String className, String version) {
         this.id = id;
         this.displayName = displayName;
         this.className = className;
@@ -20,10 +22,7 @@ public ConnectorDescriptor(String id, String displayName, String className, Stri
     }
 
     public ConnectorDescriptor(String className, String version) {
-        this.id = getIdForConnectorClass(className);
+        this(getIdForConnectorClass(className), getDisplayNameForConnectorClass(className), className, version);
-        this.displayName = getDisplayNameForConnectorClass(className);
-        this.className = className;
-        this.version = version;
     }
 
     public String getId() {
@@ -75,4 +74,20 @@ public static String getDisplayNameForConnectorClass(String className) {
                 throw new RuntimeException("Unsupported connector type with className: \"" + className + "\"");
         }
     }
+
+    @Override
+    public boolean equals(Object that) {
+        if (this == that) {
+            return true;
+        }
+        if (that == null || getClass() != that.getClass()) {
+            return false;
+        }
+        return this.getClassName().equals(((ConnectorDescriptor) that).getClassName())
+                && this.getVersion().equals(((ConnectorDescriptor) that).getVersion());
+    }
+
+    public int hashCode() {
+        return Objects.hash(this.className, this.version);
+    }
 }