HDFS-9210. Fix some misuse of %n in VolumeScanner#printStats. Contributed by Xiaoyu Yao.

(cherry picked from commit b11008d54d8aa3eb9c7c10c3a0734d95b9ef41e9)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -1772,6 +1772,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9708. FSNamesystem.initAuditLoggers() doesn't trim classnames
     (Mingliang Liu via stevel)
 
+    HDFS-9210. Fix some misuse of %n in VolumeScanner#printStats.
+    (Xiaoyu Yao)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/VolumeScanner.java

@@ -216,9 +216,8 @@ public class VolumeScanner extends Thread {
   }
 
   public void printStats(StringBuilder p) {
-    p.append("Block scanner information for volume " +
-        volume.getStorageID() + " with base path " + volume.getBasePath() +
-        "%n");
+    p.append(String.format("Block scanner information for volume %s with base" +
+        " path %s%n", volume.getStorageID(), volume.getBasePath()));
     synchronized (stats) {
       p.append(String.format("Bytes verified in last hour       : %57d%n",
           stats.bytesScannedInPastHour));
@@ -245,7 +244,7 @@ public class VolumeScanner extends Thread {
           stats.lastBlockScanned.toString())));
       p.append(String.format("More blocks to scan in period     : %57s%n",
           !stats.eof));
-      p.append("%n");
+      p.append(System.lineSeparator());
     }
   }