Java-based data access object
View Patent ↗A Database Development System is described that provides methodologies for creating a Java-based database control object (the “Java DataWindow”) for use in a Client/Server Database System. The methodology provided by the present invention maintains the DataWindow properties (e.g., SQL statement for data to retrieve, format specifications, and the like) at a server-side DataWindow component residing at an application server. A corresponding client-side DataWindow component, embedded for instance in a target HTML page, knows how to query the server-side DataWindow component for dynamically streaming the DataWindow's properties, so that they may be applied at run-time on the client side. After an end user has entered in the input desired, the changes are determined by the client-side DataWindow component and flushed back to the server-side DataWindow component at the application server. The server-side DataWindow component, in turn, can effect the changes to the back end database, as appropriate.
1. A method for providing object-based data access in a Web environment supporting Java, the method comprising:
receiving at a Web browser an end user request for displaying a Web page, thereby invoking a client-side Java-based data access component that is embedded therein;
in response to invocation of the client-side component, invoking a corresponding server-side data access component for retrieving definition information for run-time operation of the client-side component, said definition information including a database query specifying retrieval of information from a database and including a format specification specifying presentation of the information retrieved from the database to the end user; and
applying the definition information, upon receipt, to the client-side component, whereupon information of interest is retrieved from the database and is presented to the end user by the client-side component in accordance with the format specification.
2. The method of claim 1 , wherein said definition information is converted into a binary stream by the server-side component for transmission to the client-side component.
3. The method of claim 1 , wherein said server-side component resides on an application server.
4. The method of claim 1 , wherein said database query comprises an SQL statement specifying retrieval of information of interest from the database.
5. The method of claim 1 , wherein said format specification defines a presentation format for displaying information at the client-side component.
6. The method of claim 1 , wherein said Web page comprises a hypertext markup language (HTML) page.
7. The method of claim 1 , wherein said client-side component is embedded in a Java applet.
8. The method of claim 1 , further comprising:
receiving user input for interacting with said client-side component.
9. The method of claim 8 , wherein said user input includes user input for manipulating database information presented by the client-side component.
10. The method of claim 9 , wherein said manipulating step includes inserting, deleting, and updating database information presented by the client-side component.
11. The method of claim 8 , wherein said client-side component applies validation rules defined by said definition information for validating said user input.
12. The method of claim 1 , wherein said information of interest comprises database rows retrieved from one or more database tables residing on a server.
13. The method of claim 1 , wherein client-side component displays a graphical user interface, in accordance with said format specification.
14. The method of claim 1 , further comprising:
receiving user input for changing database information presented by the client-side component;
generating a stream describing what has changed and transmitting it to the server-side components;
at the server-side component, applying any described changes to the database.
15. The method of claim 14 , wherein said server side component first applies business rules to any described changes before applying said changes to the database.
16. The method of claim 1 , wherein said format specification specifies whether information retrieved from a database is modifiable.
17. The method of claim 1 , wherein said format specification may be customized to display information to the user in different presentation styles.
18. The method of claim 1 , wherein said server-side data access component retrieves information from more than one database.
19. The method of claim 1 , wherein said server-side data access component retrieves information from multiple data sources, which may include database and nondatabase sources.
20. The method of claim 1 , wherein said Java-based data access component comprises a Java programming language JavaBeans-based component.
21. The method of claim 20 , wherein said Java-based data access component comprises a native component.
22. The method of claim 21 , wherein said Java-based data access component comprises as a Java programming language lightweight Swing-based component.
23. The method of claim 1 , wherein said format specification can be modified by a user.
24. A system providing on-line interaction with databases, the system comprising:
a client-side Java based data access component that receives at a browser an end user request for information, wherein said component invokes a server-side data access component and, upon receipt of information from the server-side component, presents the information received for display in the browser in a format specified by the server-side component;
a server-side data access component for retrieving definition information for run-time operation of the client-side component, said definition information including a database query specifying retrieval of information from a database and a format specification specifying presentation of the information received from the database to the end user; and
at least one database in which information is stored.
25. The system of claim 24 , wherein said server-side component converts the definition information into a binary stream for transmission to the client-side component.
26. The system of claim 24 , wherein said server-side component resides on an application server.
27. The system of claim 24 , wherein said database query comprises an SQL statement specifying retrieval of information from a database.
28. The system of claim 24 , wherein said client-side component presents information comprising a hypertext markup language (HTML) page.
29. The system of claim 24 , wherein said client-side component is embedded in a Java applet.
30. The system of claim 24 , wherein a user may manipulate information presented by the client-side component.
31. The system of claim 24 , wherein a user may perform insert, delete, and update operations on database information presented by the client-side component.
32. The system of claim 24 , wherein said client-side component applies validation rules defined by said definition information for validating user input.
33. The system of claim 24 , wherein said client-side component receives user input for changing database information, said client-side component generates a stream describing what has changed and transmitting it to the server-side component; and said server-side component applies any described changes to one or more databases.
34. The system of claim 33 , wherein said server-side component applies business rules before applying said described changes to said databases.