Fix Serializable issues (#132)

Author: stIncMale

src/integrationTest/java/com/mongodb/hibernate/TestCommandListener.java

@@ -30,7 +30,7 @@ public final class TestCommandListener implements CommandListener, Service {
 
     static TestCommandListener INSTANCE = new TestCommandListener();
 
-    private final List<BsonDocument> startedCommands = new ArrayList<>();
+    private final transient List<BsonDocument> startedCommands = new ArrayList<>();
 
     private TestCommandListener() {}
 

src/main/java/com/mongodb/hibernate/internal/extension/service/StandardServiceRegistryScopedState.java

@@ -24,6 +24,9 @@
 import com.mongodb.hibernate.internal.cfg.MongoConfiguration;
 import com.mongodb.hibernate.internal.cfg.MongoConfigurationBuilder;
 import com.mongodb.hibernate.service.spi.MongoConfigurationContributor;
+import java.io.IOException;
+import java.io.NotSerializableException;
+import java.io.ObjectOutputStream;
 import java.io.Serial;
 import java.util.Map;
 import org.hibernate.HibernateException;
@@ -38,7 +41,7 @@ public final class StandardServiceRegistryScopedState implements Service {
     @Serial
     private static final long serialVersionUID = 1L;
 
-    private final MongoConfiguration config;
+    private final transient MongoConfiguration config;
 
     @VisibleForTesting(otherwise = PRIVATE)
     public StandardServiceRegistryScopedState(MongoConfiguration config) {
@@ -49,6 +52,12 @@ public MongoConfiguration getConfiguration() {
         return config;
     }
 
+    @Serial
+    private void writeObject(ObjectOutputStream out) throws IOException {
+        throw new NotSerializableException(
+                "This class is not designed to be serialized despite it having to implement `Serializable`");
+    }
+
     public static final class ServiceContributor implements org.hibernate.service.spi.ServiceContributor {
         public ServiceContributor() {}
 

src/main/java/com/mongodb/hibernate/internal/type/MongoStructJdbcType.java

@@ -27,6 +27,9 @@
 import static com.mongodb.hibernate.internal.type.ValueConversions.toDomainValue;
 
 import com.mongodb.hibernate.internal.FeatureNotSupportedException;
+import java.io.IOException;
+import java.io.NotSerializableException;
+import java.io.ObjectOutputStream;
 import java.io.Serial;
 import java.sql.CallableStatement;
 import java.sql.Connection;
@@ -58,7 +61,7 @@ public final class MongoStructJdbcType implements StructJdbcType {
     public static final MongoStructJdbcType INSTANCE = new MongoStructJdbcType();
     public static final JDBCType JDBC_TYPE = JDBCType.STRUCT;
 
-    private final @Nullable EmbeddableMappingType embeddableMappingType;
+    private final transient @Nullable EmbeddableMappingType embeddableMappingType;
     private final @Nullable String structTypeName;
 
     private MongoStructJdbcType() {
@@ -206,6 +209,12 @@ public <X> ValueExtractor<X> getExtractor(JavaType<X> javaType) {
         return new Extractor<>(javaType);
     }
 
+    @Serial
+    private void writeObject(ObjectOutputStream out) throws IOException {
+        throw new NotSerializableException(
+                "This class is not designed to be serialized despite it having to implement `Serializable`");
+    }
+
     /** Thread-safe. */
     private final class Binder<X> extends BasicBinder<X> {
         @Serial

src/main/java/com/mongodb/hibernate/jdbc/MongoConnectionProvider.java

@@ -56,7 +56,7 @@ public final class MongoConnectionProvider implements ConnectionProvider, Stoppa
     private static final long serialVersionUID = 1L;
 
     private @Nullable StandardServiceRegistryScopedState standardServiceRegistryScopedState;
-    private @Nullable MongoClient mongoClient;
+    private transient @Nullable MongoClient mongoClient;
 
     @Override
     public Connection getConnection() throws SQLException {