From a6a7dd71635d0a5dd0eccaf67e28ba346894fe9e Mon Sep 17 00:00:00 2001 From: Beluga Behr Date: Thu, 18 Oct 2018 09:56:20 -0400 Subject: [PATCH] Use Collections.emptyList() For Empty List Values --- .../org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java | 3 ++- .../java/org/apache/hadoop/hbase/regionserver/BaseRowProcessor.java | 4 ++-- .../org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java | 4 +++- hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java | 4 ++-- 4 files changed, 9 insertions(+), 6 deletions(-) diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java index f4abb1c..10e99a2 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java @@ -21,6 +21,7 @@ package org.apache.hadoop.hbase.master.balancer; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; +import java.util.Collections; import java.util.Comparator; import java.util.Deque; import java.util.HashMap; @@ -75,7 +76,7 @@ public abstract class BaseLoadBalancer implements LoadBalancer { protected static final int MIN_SERVER_BALANCE = 2; private volatile boolean stopped = false; - private static final List EMPTY_REGION_LIST = new ArrayList<>(0); + private static final List EMPTY_REGION_LIST = Collections.emptyList(); static final Predicate IDLE_SERVER_PREDICATOR = load -> load.getRegionMetrics().isEmpty(); diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BaseRowProcessor.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BaseRowProcessor.java index da691b7..e33a9f2 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BaseRowProcessor.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BaseRowProcessor.java @@ -18,7 +18,7 @@ package org.apache.hadoop.hbase.regionserver; import java.io.IOException; -import java.util.ArrayList; +import java.util.Collections; import java.util.List; import java.util.Locale; import java.util.UUID; @@ -57,7 +57,7 @@ implements RowProcessor { @Override public List getClusterIds() { - return new ArrayList<>(); + return Collections.emptyList(); } @Override diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java index 8caf013..ad40734 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java @@ -996,7 +996,9 @@ public class StripeStoreFileManager @Override public List getStripeBoundaries() { - if (this.state.stripeFiles.isEmpty()) return new ArrayList<>(); + if (this.state.stripeFiles.isEmpty()) { + return Collections.emptyList(); + } ArrayList result = new ArrayList<>(this.state.stripeEndRows.length + 2); result.add(OPEN_KEY); Collections.addAll(result, this.state.stripeEndRows); diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java index 5b968db..85ed2ae 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java @@ -1034,7 +1034,7 @@ public abstract class FSUtils extends CommonFSUtils { // assumes we are in a table dir. List rds = listStatusWithStatusFilter(fs, tableDir, new RegionDirFilter(fs)); if (rds == null) { - return new ArrayList<>(); + return Collections.emptyList(); } List regionDirs = new ArrayList<>(rds.size()); for (FileStatus rdfs: rds) { @@ -1101,7 +1101,7 @@ public abstract class FSUtils extends CommonFSUtils { public static List getReferenceFilePaths(final FileSystem fs, final Path familyDir) throws IOException { List fds = listStatusWithStatusFilter(fs, familyDir, new ReferenceFileFilter(fs)); if (fds == null) { - return new ArrayList<>(); + return Collections.emptyList(); } List referenceFiles = new ArrayList<>(fds.size()); for (FileStatus fdfs: fds) { -- 2.7.4