System Architecture of ArcGIS Server

 

Application Developer framework) Why useJSFTo achieveServer ADF (reproduced)

One of the reasons: full separation of behavior and representation.

A typical example of the separation of behavior and performance is normal. JSP Technology, this technology is good, because it is easy Html (And classHtml ) Hybrid Java Code . In this way, we can use powerful Java API . Of course, the obvious downside is that behavior is stuck together. And the code is not easy to reuse. This reminds me of the usage JSP Write in the text editor JSP Page, read and write the database, and the painful memories displayed on the same page.
Model1 The emergence of architecture allows developers to use JavaBean Development, more comfortable. Of course, there is better.
This has to mention the famous MVC Structure, (MVC) Model-View-controller: Model- View - The controller mode architecture provides a series of design patterns that you can easily apply Program Development, especially the development of interface programs. How many programs have no interface?
Model It encapsulates business logic and persistent data code, including database access or file access. Model It is best not to follow View There is any relationship, it is better not to know who will display the result, is Swing Interface, or JSF Interface, or ordinary JSP Interface. In order to do this, it takes some time to plan ahead, but believe me, the value of the time will be more than you think. If properly designed, many applications ArcGIS Engine The developed code can be easily stored in Server . . Net The same is true.
View It is only used to display the display logic and does not have any business logic. Controller Yes View And Model Bridge, it and Model And display the result in Model . The selection of the display page is also composed Controller Select. I will explain in detail in the subsequent lectures JSF In Controller .
Structs , Spring All are implemented MVC . But none of them look like JSF In this way, an event-driven component object model is provided. You can think about it. Html Label used in, <Input type = "text" name = "Q"> , In JSF The framework becomes a component, which can also have events and be programmed. How exciting it is! GIS The program needs to interact well with the user and select an event-driven Framework To make programming and implementation easier.

Cause 2:Events are easily bound to server code .
JSF Provides multiple event-driven Gui Widget , For example, the most common Command button . These Command button Events are generated, and we have the opportunity to program events. I have mentioned this in my previous lectures,ArcGIS Server Of Mapcontrol And Command button They all inherit from Javax. Faces. component. uicommand Is it amazing? Inherited from Uicommand The reason is to use Uicommand Many events Map Control For example, to zoom in or zoom out, events need to be generated. These events are submitted to the corresponding listener, and the listener will process the events. About Mapcontrol In the subsequent lectures, I will explain these questions in detail.
A simple example is the simplest Fullextent Tool. If I write it myself, you can write it as follows:
<H: commandbutton id = "redisplaycommand" type = "Submit" value = "full extent" actionlistener = "# {getmapbean. getfullmap}"/>
This button is used to zoom to the full graph, and its listener is bound Getmapbean Of Getfullmap Method. In this method, I will scale the map size to the full graph range. I will paste the code later. This is JSF Events are bound to the server code. A common Button Click events to map to the background Bean To perform business logic in the background method for data access. This concept is similar to the common Swing The Program Event and listener mechanism are very similar, Java Programmers must feel more cordial. Note: Button No use ADF In our ADF All the materials for building are ready for you, Fullextent The function only requires three lines of code.
Events are easily bound to the server code. This is ESRI Select JSF As we ADF Another important reason is the underlying layer.