tailieunhanh - o'reilly database programming with JDBC and Java 2nd edition phần 4

Khi phát triển cho các trang web sản xuất, tuy nhiên, bạn gần như chắc chắn muốn di chuyển đến một trình điều khiển JDBC là nguồn gốc cơ sở dữ liệu triển khai của bạn. trong khi nhiệm vụ phổ biến hơn hoặc kỳ lạ được kích hoạt thông qua | JDBC and Java 2nd edition Chapter 5. The JDBC Optional Package Narrow souls I cannot abide there s almost no good or evil inside. Friedrich Nietzsche The Gay Science The JDBC API you have covered in this book is called the JDBC Core API. The JDBC Core API is a narrowly focused specification that supports the functionality required by applications to successfully access databases. With the JDBC release however Sun added an API called the JDBC Optional Package formerly called the JDBC Standard Extension to support extended database access functionality. The JDBC version of the Optional Package encompasses the following elements Data source-oriented database access via the new JNDI API JDBC driver-based connection pooling Rowsets Distributed transactions As I write this chapter the JDBC Optional Package has just been finalized. Very few drivers support any of this functionality. I will therefore cover as much of the JDBC Optional Package in this chapter as possible but I will not be able to do full justice to some topics due to the scarcity of available information at the time of writing. Data Sources In Chapter 3 we covered how to register a JDBC driver and make a connection using a JDBC URL. Perhaps you like me and many others found this to be a bit of an annoyance especially if you are trying to write database-independent code. I am now about to tell you that all of that is completely unnecessary. You don t have to register drivers. You don t have to know anything about JDBC URLs. JDBC has discovered the marvels of naming and directory services. Naming and Directory Services Naming and directory services are basic to computing. Naming services are the tool through which programmatic things files printers file servers etc. are matched to names. You do not print to your local printer by referencing its I O port. You reference the printer by its name. A naming service inside your OS maps that printer name to an I O port. A .