[Issue:5669] Fix the ledgerID not found cause NPE (#5809)

## Motivation
when ledgers.ceilingKey return a NULL value, we need to process the ledgerId is NUll case.

## Modifications
change long ledgerId to Long ledgerId and check if ledgerId is NULL.

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/ManagedLedgerException.java

@@ -71,6 +71,10 @@ public class ManagedLedgerException extends Exception {
         public ManagedLedgerNotFoundException(Exception e) {
             super(e);
         }
+
+        public ManagedLedgerNotFoundException(String message) {
+            super(message);
+        }
     }
 
     public static class ManagedLedgerTerminatedException extends ManagedLedgerException {

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedLedgerImpl.java

@@ -1790,8 +1790,13 @@ public class ManagedLedgerImpl implements ManagedLedger, CreateCallback {
         }
     }
 
-    PositionImpl startReadOperationOnLedger(PositionImpl position) {
-        long ledgerId = ledgers.ceilingKey(position.getLedgerId());
+    PositionImpl startReadOperationOnLedger(PositionImpl position, OpReadEntry opReadEntry) {
+        Long ledgerId = ledgers.ceilingKey(position.getLedgerId());
+        if (null == ledgerId) {
+            opReadEntry.readEntriesFailed(new ManagedLedgerException.NoMoreEntriesToReadException("The ceilingKey(K key) method is used to return the " +
+                    "least key greater than or equal to the given key, or null if there is no such key"), null);
+        }
+
         if (ledgerId != position.getLedgerId()) {
             // The ledger pointed by this position does not exist anymore. It was deleted because it was empty. We need
             // to skip on the next available ledger

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/OpReadEntry.java

@@ -49,7 +49,7 @@ class OpReadEntry implements ReadEntriesCallback {
     public static OpReadEntry create(ManagedCursorImpl cursor, PositionImpl readPositionRef, int count,
             ReadEntriesCallback callback, Object ctx) {
         OpReadEntry op = RECYCLER.get();
-        op.readPosition = cursor.ledger.startReadOperationOnLedger(readPositionRef);
+        op.readPosition = cursor.ledger.startReadOperationOnLedger(readPositionRef, op);
         op.cursor = cursor;
         op.count = count;
         op.callback = callback;
@@ -128,12 +128,12 @@ class OpReadEntry implements ReadEntriesCallback {
         if (entries.size() < count && cursor.hasMoreEntries()) {
             // We still have more entries to read from the next ledger, schedule a new async operation
             if (nextReadPosition.getLedgerId() != readPosition.getLedgerId()) {
-                cursor.ledger.startReadOperationOnLedger(nextReadPosition);
+                cursor.ledger.startReadOperationOnLedger(nextReadPosition, OpReadEntry.this);
             }
 
             // Schedule next read in a different thread
             cursor.ledger.getExecutor().execute(safeRun(() -> {
-                readPosition = cursor.ledger.startReadOperationOnLedger(nextReadPosition);
+                readPosition = cursor.ledger.startReadOperationOnLedger(nextReadPosition, OpReadEntry.this);
                 cursor.ledger.asyncReadEntries(OpReadEntry.this);
             }));
         } else {