Prefer class_eval to reopening Connection class

* Should aid situation where JRuby extension (do_DRIVER_ext.jar) does
  not load and no Error is raised. (Re-)opening the class in these
  situations was causing an ArgumentError to be raised (because the
  correct #initialize method is not defined) rather than a constant
  missing error.
* Thanks to Peter Brant for helping diagnosis this behaviour.
* Remove overriden pool_size: this is now defined for JRuby in
  DataObjects::Pooling.

[#1122]

Signed-off-by: Alex Coles <alex@alexcolesportfolio.com>

do_derby/lib/do_derby.rb

@@ -18,16 +18,6 @@
   # which is currently not working as expected.
   java_import driver
 
-  module DataObjects
-    module Derby
-      class Connection
-        def self.pool_size
-          20
-        end
-      end
-    end
-  end
-
 else
   warn "do_derby is only for use with JRuby"
 end

do_h2/lib/do_h2.rb

@@ -19,16 +19,6 @@
   # which is currently not working as expected.
   java_import driver
 
-  module DataObjects
-    module H2
-      class Connection
-        def self.pool_size
-          20
-        end
-      end
-    end
-  end
-
 else
   warn "do_h2 is only for use with JRuby"
 end

do_hsqldb/lib/do_hsqldb.rb

@@ -17,16 +17,6 @@
   # which is currently not working as expected.
   java_import driver
 
-  module DataObjects
-    module Hsqldb
-      class Connection
-        def self.pool_size
-          20
-        end
-      end
-    end
-  end
-
 else
   warn "do_hsqldb is only for use with JRuby"
 end

do_mysql/lib/do_mysql.rb

@@ -26,22 +26,16 @@
 
 if RUBY_PLATFORM =~ /java/
 
-  module DataObjects
-    module Mysql
-      class Connection
-        def self.pool_size
-          20
-        end
-
-        def using_socket?
-          @using_socket
-        end
-
-        def secure?
-          false
-        end
-      end
+  DataObjects::Mysql::Connection.class_eval do
+
+    def using_socket?
+      @using_socket
+    end
+
+    def secure?
+      false
     end
+
   end
 
 end

do_oracle/lib/do_oracle.rb

@@ -114,18 +114,3 @@ def self.ruby_time_zone
     end
   end
 end
-
-if RUBY_PLATFORM =~ /java/
-
-  module DataObjects
-    module Oracle
-      class Connection
-        def self.pool_size
-          20
-        end
-
-      end
-    end
-  end
-
-end

do_postgres/lib/do_postgres.rb

@@ -21,17 +21,3 @@
 require 'do_postgres/version'
 require 'do_postgres/transaction'
 require 'do_postgres/encoding'
-
-if RUBY_PLATFORM =~ /java/
-
-  module DataObjects
-    module Postgres
-      class Connection
-        def self.pool_size
-          20
-        end
-      end
-    end
-  end
-
-end

do_sqlite3/lib/do_sqlite3.rb

@@ -24,16 +24,14 @@
 
 if RUBY_PLATFORM =~ /java/
 
-  module DataObjects
-    module Sqlite3
-      class Connection
-        def self.pool_size
-          # sqlite3 can have only one write access at a time, with this
-          # concurrent write access will result in "Database locked" errors
-          1
-        end
-      end
+  DataObjects::Sqlite3::Connection.class_eval do
+
+    def self.pool_size
+      # sqlite3 can have only one write access at a time, with this
+      # concurrent write access will result in "Database locked" errors
+      1
     end
+
   end
 
 end

do_sqlserver/lib/do_sqlserver.rb

@@ -288,31 +288,12 @@ def self.param_count cmd
   # Register SqlServer JDBC driver
   java.sql.DriverManager.registerDriver Java::net.sourceforge.jtds.jdbc.Driver.new
 
-  module DataObjects
-    module SqlServer
-      class Connection
-        def self.pool_size
-          20
-        end
-
-        def using_socket?
-          @using_socket
-        end
+  DataObjects::SqlServer::Connection.class_eval do
 
-=begin
-        # REVISIT: Does this problem even exist for Sqlserver?
-        def character_set
-          # JDBC API does not provide an easy way to get the current character set
-          reader = self.create_command("SHOW VARIABLES LIKE 'character_set_client'").execute_reader
-          reader.next!
-          char_set = reader.values[1]
-          reader.close
-          char_set.downcase
-        end
-=end
-
-      end
+    def using_socket?
+      @using_socket
     end
+
   end
 
 end