Fixed the CodeQL issues.

src/main/java/org/apache/datasketches/partitions/Partitioner.java

@@ -41,8 +41,8 @@
 /**
  * A partitioning process that can partition very large data sets into thousands to millions
  * of partitions of approximately the same size.
- * @param T the data type
- * @param S the quantiles sketch that implements both QuantilesGenericAPI and PartitioningFeature.
+ * @param <T> the data type
+ * @param <S> the quantiles sketch that implements both QuantilesGenericAPI and PartitioningFeature.
  */
 //@SuppressWarnings("unused")
 public class Partitioner<T, S extends QuantilesGenericAPI<T> & PartitioningFeature<T>> {
@@ -108,7 +108,7 @@ public List<PartitionBoundsRow<T>> partition(final S sk) {
     final int partsPerSk = (int)round(pow(guessNumParts, 1.0 / numLevels));
     this.partitionsPerSk = min(partsPerSk, maxPartsPerSk);
     final GenericPartitionBoundaries<T> gpb = sk.getPartitionBoundaries(partitionsPerSk, criteria);
-    final StackElement<T> se = new StackElement<>(gpb, stack.size() + 1, 0, "1");
+    final StackElement<T> se = new StackElement<>(gpb, 0, "1");
     stack.push(se);
     partitionSearch(stack);
     return finalPartitionList;
@@ -136,8 +136,8 @@ private void partitionSearch(final Stack<StackElement<T>> stack) {
         final S sk = fillReq.getRange(row.lowerBound, row.upperBound, row.rule);
         final GenericPartitionBoundaries<T> gpb2 = sk.getPartitionBoundaries(this.partitionsPerSk, criteria);
         final int level = stack.size() + 1;
-        final String partId = se.partId + "." + se.part + "," + level;
-        final StackElement<T> se2 = new StackElement<>(gpb2, level, 0, partId);
+        final String partId = se.levelPartId + "." + se.part + "," + level;
+        final StackElement<T> se2 = new StackElement<>(gpb2, 0, partId);
         stack.push(se2);
         partitionSearch(stack);
       }
@@ -156,12 +156,12 @@ private void partitionSearch(final Stack<StackElement<T>> stack) {
   public static class StackElement<T> {
     public final GenericPartitionBoundaries<T> gpb;
     public int part;
-    public String partId;
+    public String levelPartId;
 
-    public StackElement(final GenericPartitionBoundaries<T> gpb, final int level, final int part, final String partId) {
+    public StackElement(final GenericPartitionBoundaries<T> gpb, final int part, final String levelPartId) {
       this.gpb = gpb;
       this.part = part;
-      this.partId = partId;
+      this.levelPartId = levelPartId;
     }
   }
 
@@ -170,7 +170,7 @@ public StackElement(final GenericPartitionBoundaries<T> gpb, final int level, fi
    */
   public static class PartitionBoundsRow<T> {
     public int part;
-    public String partId;
+    public String levelPartId;
     public long approxNumDeltaItems;
     public BoundsRule rule;
     public T lowerBound;
@@ -179,7 +179,7 @@ public static class PartitionBoundsRow<T> {
     public PartitionBoundsRow(final StackElement<T> se) {
       final GenericPartitionBoundaries<T> gpb = se.gpb;
       this.part = se.part;
-      this.partId = se.partId + "." + part;
+      this.levelPartId = se.levelPartId + "." + part;
       final QuantileSearchCriteria searchCrit = gpb.getSearchCriteria();
       final T[] boundaries = gpb.getBoundaries();
       final int numParts = gpb.getNumPartitions();

src/test/java/org/apache/datasketches/partitions/ClassicPartitionsTest.java

@@ -82,7 +82,7 @@ void outputList(final List<PartitionBoundsRow<String>> list) {
     double sumSqErr = 0;
     for (int i = 0; i < numParts; i++) {
       final PartitionBoundsRow<String> row = list.get(i);
-      printf(dFmt, row.partId , (i + 1), row.lowerBound, row.upperBound, row.approxNumDeltaItems, row.rule.name());
+      printf(dFmt, row.levelPartId , (i + 1), row.lowerBound, row.upperBound, row.approxNumDeltaItems, row.rule.name());
       size = row.approxNumDeltaItems;
       sumSizes += size;
       sumAbsRelErr += Math.abs(size / meanPartSize - 1.0);

src/test/java/org/apache/datasketches/partitions/ItemsSketchFillRequestLongAsString.java

@@ -27,6 +27,7 @@
 import java.util.Comparator;
 import java.util.Random;
 
+import org.apache.datasketches.common.SketchesArgumentException;
 import org.apache.datasketches.quantiles.ItemsSketch;
 
 /**
@@ -52,8 +53,11 @@ public ItemsSketchFillRequestLongAsString(final int k, final long totalN) {
   public ItemsSketch<String> getRange(final String lowerQuantile, final String upperQuantile,
       final BoundsRule bounds) {
     final ItemsSketch<String> sk = ItemsSketch.getInstance(String.class, k, Comparator.naturalOrder());
-    final long lower = Long.parseLong(lowerQuantile.trim());
-    final long upper = Long.parseLong(upperQuantile.trim());
+    long upper, lower;
+    try {
+      lower = Long.parseLong(lowerQuantile.trim());
+      upper = Long.parseLong(upperQuantile.trim());
+    } catch (NumberFormatException e) { throw new SketchesArgumentException(e.toString()); }
     if (bounds == INCLUDE_BOTH) {
       for (long i = lower; i <= upper; i++) { sk.update(getString(i, numDigits)); }
     } else if (bounds == INCLUDE_UPPER) {

src/test/java/org/apache/datasketches/partitions/KllItemsSketchFillRequestLongAsString.java

@@ -28,6 +28,7 @@
 import java.util.Random;
 
 import org.apache.datasketches.common.ArrayOfStringsSerDe;
+import org.apache.datasketches.common.SketchesArgumentException;
 import org.apache.datasketches.kll.KllItemsSketch;
 
 /**
@@ -53,8 +54,11 @@ public KllItemsSketchFillRequestLongAsString(final int k, final long totalN) {
   public KllItemsSketch<String> getRange(final String lowerQuantile, final String upperQuantile,
       final BoundsRule bounds) {
     KllItemsSketch<String> sk = KllItemsSketch.newHeapInstance(k, Comparator.naturalOrder(), new ArrayOfStringsSerDe());
-    long lower = Long.parseLong(lowerQuantile.trim());
-    long upper = Long.parseLong(upperQuantile.trim());
+    long upper, lower;
+    try {
+      lower = Long.parseLong(lowerQuantile.trim());
+      upper = Long.parseLong(upperQuantile.trim());
+    } catch (NumberFormatException e) { throw new SketchesArgumentException(e.toString()); }
     if (bounds == INCLUDE_BOTH) {
       for (long i = lower; i <= upper; i++) { sk.update(getString(i, numDigits)); }
     } else if (bounds == INCLUDE_UPPER) {

src/test/java/org/apache/datasketches/partitions/KllPartitionsTest.java

@@ -82,7 +82,7 @@ void outputList(final List<PartitionBoundsRow<String>> list) {
     double sumSqErr = 0;
     for (int i = 0; i < numParts; i++) {
       final PartitionBoundsRow<String> row = list.get(i);
-      printf(dFmt, row.partId , (i + 1), row.lowerBound, row.upperBound, row.approxNumDeltaItems, row.rule.name());
+      printf(dFmt, row.levelPartId , (i + 1), row.lowerBound, row.upperBound, row.approxNumDeltaItems, row.rule.name());
       size = row.approxNumDeltaItems;
       sumSizes += size;
       sumAbsRelErr += Math.abs(size / meanPartSize - 1.0);

src/test/java/org/apache/datasketches/quantilescommon/LongsAsOrderableStrings.java

@@ -23,6 +23,8 @@
 import static java.lang.Math.log;
 import static org.apache.datasketches.common.Util.characterPad;
 
+import org.apache.datasketches.common.SketchesArgumentException;
+
 /**
  * Creates a string from a positive long value that is orderable in the
  * same order as its long value.
@@ -46,7 +48,11 @@ public static String getString(final long value, final int numDigits) {
    * @return the given String back to a long
    */
   public static long getLong(final String value) {
-    return Long.parseLong(value.trim());
+    long out;
+    try { out = Long.parseLong(value.trim()); } catch (NumberFormatException e) {
+      throw new SketchesArgumentException(e.toString());
+    }
+    return out;
   }
 
   /**