HBASE-19487 Remove IterablesUtil Class

Signed-off-by: Chia-Ping Tsai <chia7712@gmail.com>

hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueTestUtil.java

@@ -22,11 +22,10 @@ import java.nio.ByteBuffer;
 import java.util.Collection;
 import java.util.List;
 
+import org.apache.commons.collections4.IterableUtils;
 import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.IterableUtils;
 import org.apache.hadoop.hbase.util.Strings;
 import org.apache.yetus.audience.InterfaceAudience;
-
 import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
 
 @InterfaceAudience.Private
@@ -64,7 +63,7 @@ public class KeyValueTestUtil {
       boolean includeMemstoreTS) {
     int totalBytes = KeyValueUtil.totalLengthWithMvccVersion(kvs, includeMemstoreTS);
     ByteBuffer bb = ByteBuffer.allocate(totalBytes);
-    for (KeyValue kv : IterableUtils.nullSafe(kvs)) {
+    for (KeyValue kv : IterableUtils.emptyIfNull(kvs)) {
       KeyValueUtil.appendToByteBuffer(bb, kv, includeMemstoreTS);
     }
     bb.rewind();

hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java

@@ -28,11 +28,11 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.commons.collections4.IterableUtils;
 import org.apache.hadoop.hbase.KeyValue.Type;
 import org.apache.hadoop.hbase.io.util.StreamUtils;
 import org.apache.hadoop.hbase.util.ByteBufferUtils;
 import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.IterableUtils;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.WritableUtils;
 import org.apache.yetus.audience.InterfaceAudience;
@@ -90,7 +90,7 @@ public class KeyValueUtil {
   public static int totalLengthWithMvccVersion(final Iterable<? extends KeyValue> kvs,
       final boolean includeMvccVersion) {
     int length = 0;
-    for (KeyValue kv : IterableUtils.nullSafe(kvs)) {
+    for (KeyValue kv : IterableUtils.emptyIfNull(kvs)) {
       length += lengthWithMvccVersion(kv, includeMvccVersion);
     }
     return length;

hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java

@@ -30,8 +30,10 @@ import java.math.BigInteger;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.security.SecureRandom;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;
@@ -47,7 +49,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
 
 import com.google.protobuf.ByteString;
 
@@ -2339,21 +2340,24 @@ public class Bytes implements Comparable<Bytes> {
   }
 
   public static boolean isSorted(Collection<byte[]> arrays) {
+    if (!CollectionUtils.isEmpty(arrays)) {
       byte[] previous = new byte[0];
-    for (byte[] array : IterableUtils.nullSafe(arrays)) {
+      for (byte[] array : arrays) {
         if (Bytes.compareTo(previous, array) > 0) {
           return false;
         }
         previous = array;
       }
+    }
     return true;
   }
 
   public static List<byte[]> getUtf8ByteArrays(List<String> strings) {
-    List<byte[]> byteArrays = Lists.newArrayListWithCapacity(CollectionUtils.nullSafeSize(strings));
-    for (String s : IterableUtils.nullSafe(strings)) {
-      byteArrays.add(Bytes.toBytes(s));
+    if (CollectionUtils.isEmpty(strings)) {
+      return Collections.emptyList();
     }
+    List<byte[]> byteArrays = new ArrayList<>(strings.size());
+    strings.forEach(s -> byteArrays.add(Bytes.toBytes(s)));
     return byteArrays;
   }
 

hbase-common/src/main/java/org/apache/hadoop/hbase/util/IterableUtils.java

@@ -1,44 +0,0 @@
-/*
- * 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.hadoop.hbase.util;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-import org.apache.yetus.audience.InterfaceAudience;
-
-/**
- * Utility methods for Iterable including null-safe handlers.
- */
-@InterfaceAudience.Private
-public class IterableUtils {
-
-  private static final List<Object> EMPTY_LIST = Collections
-      .unmodifiableList(new ArrayList<>(0));
-
-  @SuppressWarnings("unchecked")
-  public static <T> Iterable<T> nullSafe(Iterable<T> in) {
-    if (in == null) {
-      return (List<T>) EMPTY_LIST;
-    }
-    return in;
-  }
-
-}