.NET/Java PDF, Tiff, Barcode SDK Library

In this chapter, we covered key topics in a programming paradigm that is central to F#, called language-oriented programming. We covered one particular concrete language format, XML, and then looked at abstracted representations of languages using abstract syntax trees. You also saw some techniques to traverse abstract syntax trees. These language representation techniques give powerful ways to manipulate concrete and abstract syntax fragments, which form a key part of modern programming. You then saw two language representation techniques that are more tightly coupled to F#: the F# workflow syntax, which is useful for embedded computational languages involving sequencing, and quotations, which let you give an alternative meaning to existing F# program fragments. Along the way, we also touched on reflection and its use to mediate between typed and untyped representations. That completes our look at F# as a language and the major programming paradigms it covers. In the following chapters, we look at the libraries that come with F# and the .NET Framework, and then move on to more applied topics, beginning with GUI programming using the .NET Windows Forms library.

barcode erstellen excel kostenlos, excel vba barcode generator, microsoft excel barcode generator free, print barcode in excel 2010, microsoft excel barcode font package, barcode font excel 2003, barcode font for excel, free barcode generator plugin for excel, how to make barcodes in excel 2016, barcode add in for excel 2013 free,

Note that in the finally clause, we also close any stream-related objects we opened earlier: if( reader != null ) reader.close(); JDBCUtil.close( pstmt); JDBCUtil.close( rset); } } In the next section, we ll cover how to read the CLOB data in small pieces.

The following diagram is a fairly complete picture of the common options available to the system architect for .NET applications (see Figure 1-1). This diagram captures some of the technologies you can employ on the individual tiers, as well as some of the different technologies you can use to marshal messages across these tiers. For example, the data access layer (DAL) may be on the client for a Windows application deployed to two physical tiers. At the data access layer of the system, if you re using SQL Server, or some other native relational database management system (RDBMS) communication protocol from other vendors, communication can occur with the RDBMS via Tabular Data Stream (TDS).

Another mechanism of reading CLOBs is useful when you have to read big CLOBs and you want to control the chunk size in which you read the data into your client buffer. The following method, _readClobInChunks(), demonstrates how to do this: /* demos how to read a CLOB in the database piecemeal. useful for large CLOBS. private static void _readClobInChunks( Connection conn ) throws SQLException, IOException { PreparedStatement pstmt = null; ResultSet rset = null; BufferedReader reader = null; try { String stmtString = "select clob_col from clob_table " + " where id = "; pstmt = conn.prepareStatement( stmtString ); pstmt.setInt( 1, 2 ); rset = pstmt.executeQuery(); while( rset.next() ) { System.out.println(": in _readClobInChunks"); Clob clob = rset.getClob( 1 ); */

and the .NET Framework offer a rich set of libraries for functional and imperative programming. In this chapter, we step back and give a broader overview of the .NET and F# libraries. Many of the types and namespaces described here are also covered elsewhere in this book. In these cases, we simply reference the relevant chapter.

Until this point, the code is very similar to the method _readClob() we discussed earlier, except that this time we are selecting the CLOB column that has 32,000 bytes of data in it. After getting the CLOB data, we can read data in chunks equal to the chunk size obtained by the method getChunkSize() or the ideal buffer size obtained by the method getBufferSize(). We can use either the chunk size or the ideal buffer size calculated by JDBC. The ideal buffer size is a multiple of the chunk size and is usually close to 32KB. The important thing is to have a buffer size as a multiple of the chunk size for optimal performance: int chunkSize = ((CLOB) clob).getChunkSize(); System.out.println( "Chunk Size:" + chunkSize ); int idealBufferSize = ((CLOB) clob).getBufferSize(); System.out.println( "Ideal buffer Size:" + idealBufferSize );