HADOOP-13140. FileSystem#initialize must not attempt to create StorageStatistics objects with null or empty schemes (Mingliang Liu via cmccabe)

(cherry picked from commit f2c1d9181f80e53890b50309b15c9ea37cb24987)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java

@@ -75,6 +75,7 @@ import org.apache.htrace.core.TraceScope;
 
 import com.google.common.annotations.VisibleForTesting;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.*;
 
 /****************************************************************
@@ -211,7 +212,13 @@ public abstract class FileSystem extends Configured implements Closeable {
    * @param conf the configuration
    */
   public void initialize(URI name, Configuration conf) throws IOException {
-    statistics = getStatistics(name.getScheme(), getClass());    
+    final String scheme;
+    if (name.getScheme() == null || name.getScheme().isEmpty()) {
+      scheme = getDefaultUri(conf).getScheme();
+    } else {
+      scheme = name.getScheme();
+    }
+    statistics = getStatistics(scheme, getClass());
     resolveSymlinks = conf.getBoolean(
         CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_KEY,
         CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_DEFAULT);
@@ -3576,6 +3583,8 @@ public abstract class FileSystem extends Configured implements Closeable {
   @Deprecated
   public static synchronized Statistics getStatistics(final String scheme,
       Class<? extends FileSystem> cls) {
+    checkArgument(scheme != null,
+        "No statistics is allowed for a file system with null scheme!");
     Statistics result = statisticsTable.get(cls);
     if (result == null) {
       final Statistics newStats = new Statistics(scheme);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/GlobalStorageStatistics.java

@@ -23,6 +23,7 @@ import java.util.NavigableMap;
 import java.util.NoSuchElementException;
 import java.util.TreeMap;
 
+import com.google.common.base.Preconditions;
 import org.apache.hadoop.classification.InterfaceAudience;
 
 /**
@@ -55,7 +56,7 @@ public enum GlobalStorageStatistics {
    *                      null if there is none.
    */
   public synchronized StorageStatistics get(String name) {
-    return map.get(name);
+    return name == null ? null : map.get(name);
   }
 
   /**
@@ -70,6 +71,8 @@ public enum GlobalStorageStatistics {
    */
   public synchronized StorageStatistics put(String name,
       StorageStatisticsProvider provider) {
+    Preconditions.checkNotNull(name,
+        "Storage statistics can not have a null name!");
     StorageStatistics stats = map.get(name);
     if (stats != null) {
       return stats;