Re: Java as a scripting language

x x <mcartoaje@gmail.com> writes:


  When writing ?throw away? scripts, I am faster sometimes,
  because I do not care to do everything perfect. I might
  try to use such a style in Java, too, sometimes:

  So I define (at least) two levels of a ?Java scripting style?.
 
  For example, I wrote this to create an SQL statement:

private static void appendToOutput
( final java.util.ArrayList<java.lang.Throwable> log,
  final java.lang.StringBuilder output,
  final java.sql.Connection conn )
throws java.sql.SQLException
{ final java.sql.Statement statement = conn.createStatement();
  try
  { if( statement.execute( query ))
    appendToOutput( log, output, statement ); }
  finally
  { try
    { statement.close(); }
    catch( final java.lang.Exception exception )
    { log.add( exception ); }}}

  The intention was to create industrial-strength code,
  but it might be somewhat hard to read and to write.

  Sometimes, it might be appropriate to relax requirements.

  For example: Sunny-weather coding: Assume there will be
  no run-time errors (including exceptions):

private static void appendToOutput
( final java.lang.StringBuilder output,
  final java.sql.Connection conn )
throws java.lang.Exception
{ final java.sql.Statement statement = conn.createStatement();
  statement.execute( query )
  appendToOutput( log, output, statement );
  statement.close(); }

  I even consider starting with this version in teaching,
  because it will help beginners to see the intended flow,
  before everything gets hidden unter exception-related code.

  Java scripting style level 2 even does not care anymore to
  close everything properly, I might even drop ?private? and my
  beloved ?final? and ?java.lang?:

static void appendToOutput( StringBuilder output, Connection conn )
throws Throwable
{ conn.createStatement().execute( query )
  appendToOutput( log, output, statement ); }

  This is dirty code, but as a first step in teaching it might
  help to see the intended operation of this method clearly and
  might be ok in teaching /if/ the drawbacks and problems of
  this style also are explained and a more robust solution is
  shown later.

  It might also be appropriate, if one needs to get first
  /quick/ implementation of something in Java (?quick and dirty?).