HADOOP-10812. Delegate KeyProviderExtension#toString to underlying KeyProvider. (wang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1609416 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -177,6 +177,9 @@ Trunk (Unreleased)
     HADOOP-10769. Create KeyProvider extension to handle delegation tokens.
     (Arun Suresh via atm)
 
+    HADOOP-10812. Delegate KeyProviderExtension#toString to underlying
+    KeyProvider. (wang)
+
   BUG FIXES
 
     HADOOP-9451. Fault single-layer config if node group topology is enabled.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/KeyProviderExtension.java

@@ -120,4 +120,9 @@ public abstract class KeyProviderExtension
   public void flush() throws IOException {
     keyProvider.flush();
   }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + ": " + keyProvider.toString();
+  }
 }