Refactor: Ensure all resources are closed when exceptions are thrown

Author: ennuite

flight/flight-sql-jdbc-core/src/main/java/org/apache/arrow/driver/jdbc/ArrowFlightConnection.java

@@ -20,7 +20,7 @@
 
 import io.netty.util.concurrent.DefaultThreadFactory;
 import java.sql.SQLException;
-import java.util.List;
+import java.util.ArrayList;
 import java.util.Properties;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -183,17 +183,26 @@ public Properties getClientInfo() {
   public void close() throws SQLException {
     Exception topLevelException = null;
     try {
-      AutoCloseables.close(List.copyOf(statementMap.values()));
+      if (executorService != null) {
+        executorService.shutdown();
+      }
     } catch (final Exception e) {
       topLevelException = e;
     }
+    ArrayList<AutoCloseable> closeables = new ArrayList<>(statementMap.values());
+    closeables.add(clientHandler);
+    closeables.addAll(allocator.getChildAllocators());
+    closeables.add(allocator);
     try {
-      AutoCloseables.close(clientHandler);
-      if (executorService != null) {
-        executorService.shutdown();
+      AutoCloseables.close(closeables);
+    } catch (final Exception e) {
+      if (topLevelException == null) {
+        topLevelException = e;
+      } else {
+        topLevelException.addSuppressed(e);
       }
-      allocator.getChildAllocators().forEach(AutoCloseables::closeNoChecked);
-      AutoCloseables.close(allocator);
+    }
+    try {
       super.close();
     } catch (final Exception e) {
       if (topLevelException == null) {