#2310 Add CollectionUtils to common module

Author: emeroad

commons/src/main/java/com/navercorp/pinpoint/common/util/CollectionUtils.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2016 NAVER Corp.
+ *
+ * Licensed 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 com.navercorp.pinpoint.common.util;
+
+import java.util.Collection;
+
+/**
+ * @author Woonduk Kang(emeroad)
+ */
+public final class CollectionUtils {
+
+    private CollectionUtils() {
+    }
+
+    public static <T> int nullSafeSize(Collection<T> collection) {
+        return nullSafeSize(collection, 0);
+    }
+
+    public static <T> int nullSafeSize(Collection<T> collection, int nullValue) {
+        if (collection == null) {
+            return nullValue;
+        }
+        return collection.size();
+    }
+
+    public static <T> boolean isEmpty(Collection<T> collection) {
+        return collection == null || collection.isEmpty();
+    }
+
+    public static <T> boolean isNotEmpty(Collection<T> collection) {
+        return !isEmpty(collection);
+    }
+}

commons/src/test/java/com/navercorp/pinpoint/common/util/CollectionUtilsTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2016 NAVER Corp.
+ *
+ * Licensed 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 com.navercorp.pinpoint.common.util;
+
+import com.google.common.collect.Lists;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Collections;
+
+
+/**
+ * @author Woonduk Kang(emeroad)
+ */
+public class CollectionUtilsTest {
+
+    @Test
+    public void nullSafeSize() throws Exception {
+        Assert.assertEquals(CollectionUtils.nullSafeSize(Lists.newArrayList(123)), 1);
+
+        Assert.assertEquals(CollectionUtils.nullSafeSize(Collections.emptyList()), 0);
+        Assert.assertEquals(CollectionUtils.nullSafeSize(null), 0);
+    }
+
+    @Test
+    public void nullSafeSize_nullValue() throws Exception {
+        Assert.assertEquals(CollectionUtils.nullSafeSize(null, -1), -1);
+    }
+
+    @Test
+    public void isEmpty() throws Exception {
+        Assert.assertTrue(CollectionUtils.isEmpty(null));
+        Assert.assertTrue(CollectionUtils.isEmpty(Collections.emptyList()));
+    }
+
+    @Test
+    public void isNotEmpty() throws Exception {
+        Assert.assertFalse(CollectionUtils.isNotEmpty(Collections.emptyList()));
+        Assert.assertFalse(CollectionUtils.isNotEmpty(null));
+    }
+
+}

rpc/src/main/java/com/navercorp/pinpoint/rpc/util/ListUtils.java

@@ -16,6 +16,9 @@
 
 package com.navercorp.pinpoint.rpc.util;
 
+import com.navercorp.pinpoint.common.util.CollectionUtils;
+
+import java.util.Collection;
 import java.util.List;
 
 /**
@@ -26,12 +29,12 @@ public final class ListUtils {
     private ListUtils() {
     }
 
+    /**
+     * @deprecated Since 1.6.1. Use {@link CollectionUtils#isEmpty(Collection)}
+     */
+    @Deprecated
     public static boolean isEmpty(List list) {
-        if (list == null || list.isEmpty()) {
-            return true;
-        }
-
-        return false;
+        return CollectionUtils.isEmpty(list);
     }
 
     public static <V> boolean addIfValueNotNull(List<V> list, V value) {

web/src/main/java/com/navercorp/pinpoint/web/dao/hbase/HbaseApplicationTraceIndexDao.java

@@ -28,7 +28,6 @@
 import com.navercorp.pinpoint.common.server.util.SpanUtils;
 import com.navercorp.pinpoint.common.util.TimeUtils;
 import com.navercorp.pinpoint.common.util.TransactionId;
-import com.navercorp.pinpoint.rpc.util.ListUtils;
 import com.navercorp.pinpoint.web.dao.ApplicationTraceIndexDao;
 import com.navercorp.pinpoint.web.mapper.TraceIndexScatterMapper2;
 import com.navercorp.pinpoint.web.mapper.TraceIndexScatterMapper3;
@@ -40,6 +39,7 @@
 import com.navercorp.pinpoint.web.vo.SelectedScatterArea;
 import com.navercorp.pinpoint.web.vo.scatter.Dot;
 import com.sematext.hbase.wd.AbstractRowKeyDistributor;
+import org.apache.commons.collections.CollectionUtils;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.client.Result;
@@ -296,7 +296,7 @@ public ScatterData scanTraceScatterData(String applicationName, Range range, int
         TraceIndexScatterMapper3 mapper = new TraceIndexScatterMapper3(range.getFrom(), range.getTo(), xGroupUnit, yGroupUnit);
         List<ScatterData> dotGroupList = hbaseOperations2.findParallel(HBaseTables.APPLICATION_TRACE_INDEX, scan, traceIdRowKeyDistributor, limit, mapper, APPLICATION_TRACE_INDEX_NUM_PARTITIONS);
 
-        if (ListUtils.isEmpty(dotGroupList)) {
+        if (CollectionUtils.isEmpty(dotGroupList)) {
             return new ScatterData(range.getFrom(), range.getTo(), xGroupUnit, yGroupUnit);
         } else {
             ScatterData firstScatterData = dotGroupList.get(0);