HADOOP-4407. HADOOP-4395 should use a Java 1.5 API for 0.18. (szetszwo)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/branches/branch-0.18@704291 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -21,6 +21,8 @@ Release 0.18.2 - Unreleased
     HADOOP-4351. FSNamesystem.getBlockLocationsInternal throws
     ArrayIndexOutOfBoundsException. (hairong)
 
+    HADOOP-4407. HADOOP-4395 should use a Java 1.5 API for 0.18.  (szetszwo)
+
   NEW FEATURES
 
     HADOOP-2421.  Add jdiff output to documentation, listing all API

src/hdfs/org/apache/hadoop/dfs/FSImage.java

@@ -1371,7 +1371,7 @@ class FSImage extends Storage {
 
   static String readString_EmptyAsNull(DataInputStream in) throws IOException {
     final String s = readString(in);
-    return s.isEmpty()? null: s;
+    return s.length() == 0? null: s;
   }
 
   static byte[] readBytes(DataInputStream in) throws IOException {