HADOOP-13605. Clean up FileSystem javadocs, logging; improve diagnostics on FS load. Contributed by Steve Loughran

hadoop-common-project/hadoop-common/src/site/markdown/filesystem/filesystem.md

@@ -416,7 +416,7 @@ If the filesystem is not location aware, it SHOULD return
         BlockLocation(["localhost:50010"] ,
                   ["localhost"],
                   ["/default/localhost"]
-                   0, F.getLen())
+                   0, f.getLen())
        ] ;
 
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileSystemCaching.java

@@ -95,16 +95,14 @@ public class TestFileSystemCaching {
     try {
       fs = FileSystem.get(URI.create("//host"), conf);
       fail("got fs with auth but no scheme");
-    } catch (Exception e) {
-      assertEquals("No FileSystem for scheme: null", e.getMessage());
+    } catch (UnsupportedFileSystemException e) {
     }
     
     // no scheme, different auth
     try {
       fs = FileSystem.get(URI.create("//host2"), conf);
       fail("got fs with auth but no scheme");
-    } catch (Exception e) {
-      assertEquals("No FileSystem for scheme: null", e.getMessage());
+    } catch (UnsupportedFileSystemException e) {
     }
   }