Fix inconsistent equals and hashCode

extensions-core/google-extensions/src/main/java/org/apache/druid/firehose/google/GoogleBlob.java

@@ -72,5 +72,10 @@ public boolean equals(Object o)
     return Objects.equals(bucket, that.bucket) &&
            Objects.equals(path, that.path);
   }
-}
 
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(bucket, path);
+  }
+}

extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/LoadingLookupFactory.java

@@ -29,6 +29,7 @@
 
 import javax.annotation.Nullable;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 @JsonTypeName("loadingLookup")
@@ -137,6 +138,11 @@ public boolean equals(Object o)
     return reverseLoadingCache != null
            ? reverseLoadingCache.equals(that.reverseLoadingCache)
            : that.reverseLoadingCache == null;
+  }
 
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(dataFetcher, loadingCache, reverseLoadingCache);
   }
 }

extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/PollingLookupFactory.java

@@ -30,6 +30,7 @@
 import org.joda.time.Period;
 
 import javax.annotation.Nullable;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 @JsonTypeName("pollingLookup")
@@ -155,6 +156,11 @@ public boolean equals(Object o)
            ? (that.cacheFactory != null
               && cacheFactory.getClass() == (that.cacheFactory).getClass())
            : that.cacheFactory == null;
+  }
 
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(pollPeriod, dataFetcher, cacheFactory);
   }
 }

extensions-core/lookups-cached-single/src/main/java/org/apache/druid/server/lookup/jdbc/JdbcDataFetcher.java

@@ -38,6 +38,7 @@
 import java.sql.SQLException;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 public class JdbcDataFetcher implements DataFetcher<String, String>
 {
@@ -183,6 +184,12 @@ public boolean equals(Object o)
 
   }
 
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(connectorConfig, table, keyColumn, valueColumn);
+  }
+
   @Override
   public String toString()
   {

extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/StandardDeviationPostAggregator.java

@@ -150,4 +150,10 @@ public boolean equals(Object o)
 
     return true;
   }
+
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(name, fieldName, estimator, isVariancePop);
+  }
 }

processing/src/main/java/org/apache/druid/query/extraction/IdentityExtractionFn.java

@@ -82,6 +82,12 @@ public boolean equals(Object o)
     return o != null && o instanceof IdentityExtractionFn;
   }
 
+  @Override
+  public int hashCode()
+  {
+    return 0;
+  }
+
   public static final IdentityExtractionFn getInstance()
   {
     return INSTANCE;

processing/src/main/java/org/apache/druid/query/ordering/StringComparators.java

@@ -87,6 +87,12 @@ public boolean equals(Object o)
       return true;
     }
 
+    @Override
+    public int hashCode()
+    {
+      return 0;
+    }
+
     @Override
     public String toString()
     {
@@ -269,6 +275,12 @@ public boolean equals(Object o)
       return true;
     }
 
+    @Override
+    public int hashCode()
+    {
+      return 0;
+    }
+
     @Override
     public String toString()
     {
@@ -314,10 +326,15 @@ public boolean equals(Object o)
       if (o == null || getClass() != o.getClass()) {
         return false;
       }
-
       return true;
     }
 
+    @Override
+    public int hashCode()
+    {
+      return 0;
+    }
+
     @Override
     public String toString()
     {
@@ -410,10 +427,15 @@ public boolean equals(Object o)
       if (o == null || getClass() != o.getClass()) {
         return false;
       }
-
       return true;
     }
 
+    @Override
+    public int hashCode()
+    {
+      return 0;
+    }
+
     @Override
     public byte[] getCacheKey()
     {
@@ -461,6 +483,12 @@ public boolean equals(Object o)
       return true;
     }
 
+    @Override
+    public int hashCode()
+    {
+      return 0;
+    }
+
     @Override
     public byte[] getCacheKey()
     {

processing/src/main/java/org/apache/druid/query/search/InsensitiveContainsSearchQuerySpec.java

@@ -53,4 +53,10 @@ public boolean equals(Object o)
     }
     return super.equals(o);
   }
+
+  @Override
+  public int hashCode()
+  {
+    return super.hashCode();
+  }
 }