Troubleshoot JSP programs that are not directly, code, and UI-mixed pain: jspwidget

js| Program | Solution introduces a very good Java, Web-based UI solution, people who use Java as a Web application know that the pain of UI development on the Web, the UI performance is almost no ready-made controls, This point. NET is indeed a bit stronger than Java, even if struts does not provide a good solution jspwidget is an open source UI framework in Taiwan that provides event-driven, page state saving (viewstate), checksum , as well as common components (DropdownList, Panel, TreeView, menu) and other solutions. and provide detailed documentation and demo. In fact, saw this project a year ago, and today occasionally see the recommendation to everyone, hope can learn, reference, learn from his ideas.

Project Address: Http://edu.uuu.com.tw/jspwidget

Take a look at his menu component. The effect is cool: http://edu.uuu.com.tw/jspwidget/docs/gui/menu_03.jsp

The following is a section of the author's analysis of WebUI:

Design Objectives
The development of web-based applications has 儼 become the dominant trend in the future, the JSP is equipped with all the services such as the Java cross-platform and accessible EE structure, and is the best web site technology to consider in the development of the enterprise.
However, it is not easy to use JSP to develop WEB applications, because JSP is a non-event driver writing mode (Non Event-driven Computing model), UI (HTML Elements) can not be directly controlled by the code, and the state of the UI (View state) can not be automatically saved, these factors cause the code of the JSP and the UI mix together, the wrong complex complex ui/code not only in the development is not easy, also cause the maintenance and expansion of the day after the difficulty.

In contrast to traditional Client Forms or client-based Web applications programming patterns, JSP obviously does not feel much straight. The reason for this is three, and the list is as follows:

Factor Client Forms Pure JSP
Event-driven Computing Model You can write event-processing functions (events Handler) to justify the events that the GUI components is touching. such as the Button's OnClick event or the DropdownList onselectchanged event. Because JSP is from top to bottom sequential processing (sequential processing), so you have to use a program to determine exactly which button the user presses, whether the user changes the selected item, and so on, and then write the response code based on the results of those judgments.
GUI Compoment all GUI compoment and behavior can be fully accessed and controlled by the code, and the code and UI are completely separated. Because JSP is sequential processing, you have to insert the code into the appropriate JSP file location to change the UI for output to the Browse viewer. But writing in this way often causes the code to mix with the UI, which is very difficult to protect and expand.
Retain view state automatically undoubtedly, in traditional client forms, the state of the GUI component is automatically maintained in the last user's state of change. Because HTTP is not persisted (stateless), all HTML element status (View state) disappears after post back to the Web server. You have to write a program to keep the final user from changing the GUI compoment. It is not easy to keep the state of the HTML element (View state), and different HTML element needs to be handled in different ways. Typically, about 25% of the code is purely a matter of view in the Client Form.


The Jspwidget is a set of frameworks built on the JSP standard, designed to allow programmers to develop a JSP WEB application system in a way that is as easy as developing a traditional Client Form, as it is to create a code.