Simplify exceptions handling

Author: kovyrin

core/src/main/ruby/shell/commands.rb

@@ -8,7 +8,7 @@ def initialize(shell)
       end
 
       def command_safe(debug, *args)
-        command(*args)
+        translate_hbase_exceptions(*args) { command(*args) }
       rescue => e
         puts
         puts "ERROR: #{e}"
@@ -42,8 +42,13 @@ def format_simple_command
         formatter.footer(now)
       end
 
-      def check_table(table)
-        raise ArgumentError, "Unknown table #{table}!" unless admin.exists?(table)
+      def translate_hbase_exceptions(*args)
+        yield
+      rescue org.apache.hadoop.hbase.TableNotFoundException
+        raise "Unknown table #{args.first}!"
+      rescue org.apache.hadoop.hbase.regionserver.NoSuchColumnFamilyException
+        valid_cols = table(args.first).get_all_columns.map { |c| c + '*' }
+        raise "Unknown column family! Valid column names: #{valid_cols.join(", ")}"
       end
     end
   end

core/src/main/ruby/shell/commands/alter.rb

@@ -29,7 +29,6 @@ def help
       end
 
       def command(table, *args)
-        check_table(table)
         format_simple_command do
           admin.alter(table, *args)
         end

core/src/main/ruby/shell/commands/count.rb

@@ -14,7 +14,6 @@ def help
       end
 
       def command(table, interval = 1000)
-        check_table(table)
         now = Time.now
         formatter.header
         count = table(table).count(interval) do |cnt, row|

core/src/main/ruby/shell/commands/delete.rb

@@ -14,7 +14,6 @@ def help
       end
 
       def command(table, row, column, timestamp = org.apache.hadoop.hbase.HConstants::LATEST_TIMESTAMP)
-        check_table(table)
         format_simple_command do
           table(table).delete(row, column, timestamp)
         end

core/src/main/ruby/shell/commands/deleteall.rb

@@ -13,7 +13,6 @@ def help
       end
 
       def command(table, row, column = nil, timestamp = org.apache.hadoop.hbase.HConstants::LATEST_TIMESTAMP)
-        check_table(table)
         format_simple_command do
           table(table).deleteall(row, column, timestamp)
         end

core/src/main/ruby/shell/commands/describe.rb

@@ -9,7 +9,6 @@ def help
       end
 
       def command(table)
-        check_table(table)
         now = Time.now
         desc = admin.describe(table)
         formatter.header([ "DESCRIPTION", "ENABLED" ], [ 64 ])

core/src/main/ruby/shell/commands/disable.rb

@@ -8,7 +8,6 @@ def help
       end
 
       def command(table)
-        check_table(table)
         format_simple_command do
           admin.disable(table)
         end

core/src/main/ruby/shell/commands/drop.rb

@@ -11,7 +11,6 @@ def help
       end
 
       def command(table)
-        check_table(table)
         format_simple_command do
           admin.drop(table)
         end

core/src/main/ruby/shell/commands/enable.rb

@@ -8,7 +8,6 @@ def help
       end
 
       def command(table)
-        check_table(table)
         format_simple_command do
           admin.enable(table)
         end

core/src/main/ruby/shell/commands/exists.rb

@@ -8,7 +8,6 @@ def help
       end
 
       def command(table)
-        check_table(table)
         format_simple_command do
           formatter.row([
             "Table #{table} " + (admin.exists?(table.to_s) ? "does exist" : "does not exist")