Merge pull request #472 from apache/fix_spot_bugs_issues2

This fixes the remaining spotBugs issues.

Author: leerho

README.md

@@ -150,3 +150,9 @@ In Eclipse, open the project *Properties / Java Build Path / Module Dependencies
 
 **NOTE:** If you execute *Maven/Update Project...* from Eclipse with the option *Update project configuration from pom.xml* checked, all of the above will be erased, and you will have to redo it.
 
+## Known Issues
+
+#### SpotBugs
+
+* Make sure you configure SpotBugs with the /tools/FindBugsExcludeFilter.xml file. Otherwise, you will get a lot of false positive or low risk issues that we have examined and exliminated with this exclusion file.
+

src/main/java/org/apache/datasketches/common/Util.java

@@ -767,7 +767,7 @@ public static int numDigits(int n) {
    * @return the given number to a string prepended with spaces
    */
   public static String intToFixedLengthString(final int number, final int length) {
-    final String num = Integer.valueOf(number).toString();
+    final String num = Integer.toString(number);
     return characterPad(num, length, ' ', false);
   }
 

src/main/java/org/apache/datasketches/kll/KllItemsSketch.java

@@ -240,10 +240,10 @@ public double[] getRanks(final T[] quantiles, final QuantileSearchCriteria searc
   }
 
   @Override
-  public KllItemsSketchSortedView<T> getSortedView() {
+  public final KllItemsSketchSortedView<T> getSortedView() {
     if (isEmpty()) { throw new SketchesArgumentException(EMPTY_MSG); }
-    refreshSortedView();
-    return kllItemsSV;
+    return refreshSortedView();
+    //return kllItemsSV; //SpotBugs EI_EXPOSE_REP, Suppressed by FindBugsExcludeFilter
   }
 
   @Override
@@ -301,8 +301,11 @@ MemoryRequestServer getMemoryRequestServer() {
   @Override
   abstract int getMinMaxSizeBytes();
 
-  private final void refreshSortedView() {
-    kllItemsSV = (kllItemsSV == null) ? new KllItemsSketchSortedView<T>(this) : kllItemsSV;
+  private final KllItemsSketchSortedView<T> refreshSortedView() {
+    final KllItemsSketchSortedView<T> sv = (kllItemsSV == null)
+        ? kllItemsSV = new KllItemsSketchSortedView<T>(this)
+        : kllItemsSV;
+    return sv;
   }
 
   abstract T[] getRetainedItemsArray();

src/main/java/org/apache/datasketches/kll/KllItemsSketchSortedView.java

@@ -58,9 +58,8 @@ public class KllItemsSketchSortedView<T> implements GenericSortedView<T> {
    * @param totalN the total number of items presented to the sketch.
    * @param minItem used to extract the type of T
    * @param comparator the Comparator for type T
-   *
    */
-  public KllItemsSketchSortedView(
+  KllItemsSketchSortedView(
       final T[] quantiles,
       final long[] cumWeights,
       final long totalN,
@@ -77,7 +76,7 @@ public KllItemsSketchSortedView(
    * Constructs this Sorted View given the sketch
    * @param sk the given KllItemsSketch.
    */
-  public KllItemsSketchSortedView(final KllItemsSketch<T> sk) {
+  KllItemsSketchSortedView(final KllItemsSketch<T> sk) {
     this.totalN = sk.getN();
     this.minItem = sk.getMinItem();
     final Object[] srcQuantiles = sk.getTotalItemsArray();

src/main/java/org/apache/datasketches/quantiles/ItemsSketch.java

@@ -581,7 +581,8 @@ public void putMemory(final WritableMemory dstMem, final ArrayOfItemsSerDe<T> se
 
   @Override
   public GenericSortedView<T> getSortedView() {
-    return new ItemsSketchSortedView<T>(this);
+    if (isEmpty()) { throw new SketchesArgumentException(EMPTY_MSG); }
+    return refreshSortedView();
   }
 
   @Override
@@ -605,8 +606,11 @@ public void update(final T item) {
 
   // Restricted
 
-  private final void refreshSortedView() {
-    classicQisSV = (classicQisSV == null) ? new ItemsSketchSortedView<T>(this) : classicQisSV;
+  private final ItemsSketchSortedView<T> refreshSortedView() {
+    final ItemsSketchSortedView<T> sv = (classicQisSV == null)
+        ? classicQisSV = new ItemsSketchSortedView<T>(this)
+        : classicQisSV;
+    return sv;
   }
 
   /**

src/main/java/org/apache/datasketches/quantiles/ItemsSketchSortedView.java

@@ -41,7 +41,7 @@
  * @author Kevin Lang
  * @author Alexander Saydakov
  */
-public final class ItemsSketchSortedView<T> implements GenericSortedView<T> {
+public class ItemsSketchSortedView<T> implements GenericSortedView<T> {
   private final T[] quantiles;
   private final long[] cumWeights; //comes in as individual weights, converted to cumulative natural weights
   private final long totalN;
@@ -54,7 +54,10 @@ public final class ItemsSketchSortedView<T> implements GenericSortedView<T> {
    * @param totalN the total number of items presented to the sketch.
    * @param comparator comparator for type T
    */
-  ItemsSketchSortedView(final T[] quantiles, final long[] cumWeights, final long totalN,
+  ItemsSketchSortedView(
+      final T[] quantiles,
+      final long[] cumWeights,
+      final long totalN,
       final Comparator<T> comparator) {
     this.quantiles = quantiles;
     this.cumWeights = cumWeights;

src/main/java/org/apache/datasketches/quantilescommon/GenericSortedViewIterator.java

@@ -35,8 +35,8 @@ public class GenericSortedViewIterator<T> implements SortedViewIterator {
   private int index;
 
   public GenericSortedViewIterator(final T[] quantiles, final long[] cumWeights) {
-    this.quantiles = quantiles;
-    this.cumWeights = cumWeights;
+    this.quantiles = quantiles;   //SpotBugs EI_EXPOSE_REP2 suppressed by FindBugsExcludeFilter
+    this.cumWeights = cumWeights; //SpotBugs EI_EXPOSE_REP2 suppressed by FindBugsExcludeFilter
     this.totalN = (cumWeights.length > 0) ? cumWeights[cumWeights.length - 1] : 0;
     index = -1;
   }

src/test/java/org/apache/datasketches/common/TestUtil.java

@@ -29,7 +29,7 @@
  */
 public final class TestUtil  {
 
-  private static String userDir = System.getProperty("user.dir");
+  private static final String userDir = System.getProperty("user.dir");
 
   /**
    * TestNG group constants
@@ -41,17 +41,17 @@ public final class TestUtil  {
   /**
    * The full target Path for Java serialized sketches to be tested by other languages.
    */
-  public static Path javaPath = createPath("target/java_generated_files");
+  public static final Path javaPath = createPath("target/java_generated_files");
 
   /**
    * The full target Path for C++ serialized sketches to be tested by Java.
    */
-  public static Path cppPath = createPath("target/cpp_generated_files");
+  public static final Path cppPath = createPath("target/cpp_generated_files");
 
   /**
    * The full target Path for historical C++ serialized sketches to be tested by Java.
    */
-  public static Path cppHistPath = createPath("src/test/resources");
+  public static final Path cppHistPath = createPath("src/test/resources");
 
   private static Path createPath(final String projectLocalDir) {
     try {

src/test/java/org/apache/datasketches/kll/KllCrossLanguageTest.java

@@ -161,7 +161,7 @@ public int compare(final String s1, final String s2) {
         try {
           final int i1 = Integer.parseInt(s1);
           final int i2 = Integer.parseInt(s2);
-          return Integer.valueOf(i1).compareTo(i2);
+          return Integer.compare(i1, i2);
         } catch (NumberFormatException e) {
           throw new RuntimeException(e);
         }

src/test/java/org/apache/datasketches/kll/KllItemsSketchSortedViewString.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.datasketches.kll;
+
+import java.util.Comparator;
+
+/**
+ * For testing only
+ */
+public class KllItemsSketchSortedViewString extends KllItemsSketchSortedView<String> {
+
+  public KllItemsSketchSortedViewString(
+      final String[] quantiles,
+      final long[] cumWeights,
+      final long totalN,
+      final String minItem,
+      final Comparator<String> comparator) {
+    super(quantiles, cumWeights, totalN, minItem, comparator);
+  }
+}