HADOOP-12895. SSLFactory#createSSLSocketFactory exception message is wrong. Contributed by Wei-Chiu Chuang.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/ssl/SSLFactory.java

@@ -212,7 +212,8 @@ public class SSLFactory implements ConnectionConfigurator {
   public SSLServerSocketFactory createSSLServerSocketFactory()
     throws GeneralSecurityException, IOException {
     if (mode != Mode.SERVER) {
-      throw new IllegalStateException("Factory is in CLIENT mode");
+      throw new IllegalStateException(
+          "Factory is not in SERVER mode. Actual mode is " + mode.toString());
     }
     return context.getServerSocketFactory();
   }
@@ -229,7 +230,8 @@ public class SSLFactory implements ConnectionConfigurator {
   public SSLSocketFactory createSSLSocketFactory()
     throws GeneralSecurityException, IOException {
     if (mode != Mode.CLIENT) {
-      throw new IllegalStateException("Factory is in CLIENT mode");
+      throw new IllegalStateException(
+          "Factory is not in CLIENT mode. Actual mode is " + mode.toString());
     }
     return context.getSocketFactory();
   }
@@ -241,7 +243,8 @@ public class SSLFactory implements ConnectionConfigurator {
    */
   public HostnameVerifier getHostnameVerifier() {
     if (mode != Mode.CLIENT) {
-      throw new IllegalStateException("Factory is in CLIENT mode");
+      throw new IllegalStateException(
+          "Factory is not in CLIENT mode. Actual mode is " + mode.toString());
     }
     return hostnameVerifier;
   }