JSP and a detailed analysis BEAN

JSP has a lot to learn, here we introduce the JSP, and BEAN, including the introduction Servlet used to write the business layer is very strong and so on.

Simply put, SUN first developed Servlet, more robust functionality, system design is also very advanced, but, it outputs HTML statement or CGI use the old way, is a one output, therefore, is very inconvenient to write and modify HTML. SUN ASP was introduced similar to the mosaic type of JSP, the JSP TAG statement embedded into HTML, so that would greatly simplify and facilitate the web design and modification.

New network languages such as ASP, PHP, JSP are Inlaid SCRIPT language

Three layers from the network point of view, a network project for at least three layers: data layer, business layer, presentation layer. Of course, can also be more complex. Servlet used to write the business layer is very powerful, but very convenient for the written presentation layer. JSP is written primarily for the convenience of presentation layer is designed. Of course, you can write business layer. Was used to ASP, PHP, CGI friends, often unconsciously, the presentation layer and business layer mixed. Like that in front of friends, to process information into the JSP in the database, in fact, it should be placed in the business layer.

According to SUN own recommendation, JSP that should be kept with the presentation layer only related to the East, that is, only put part of the output HTML page. And all the data calculation, data analysis, database connection handling, all belong to business layer, should be placed in JAVA BEANS. Called by JSP JAVA BEANS, to achieve the integration of two.

In fact, Microsoft recently introduced DNA technology, simply, is that ASP + COM / DCOM technology. And JSP and BEANS completely similar to the presentation layer of all completed by the ASP, all the business layer from the COM / DCOM completed. By calling, to achieve integration.

Why should we use these components technology? As simple ASP / JSP language is very inefficient implementation, if there is a large number of user clicks, pure SCRIPT language quickly reached the limit of his capabilities, and component technology can significantly improve the function of the ceiling, accelerate the pace of implementation.

On the other hand, pure SCRIPT language presentation layer and business layer will be mixed, resulting in changes inconvenient, and the code can not be reused. If you want to change a place, often involving dozens of pages CODE, with component technology will only change components on it.

In summary, Servlet is an early imperfect product, writing a good business layer, presentation layer was very foul, and two mixed.

Therefore, the introduction of JSP and BAEN, written with JSP presentation layer, using BAEN written business layer. SUN is the meaning of their own future alternative use JSP Servlet.

However, this is not to say, learned the Servlet useless, in fact, you should from the Servlet entry, then the JSP, then the JSP and BEAN.

Stress: Studies of the JSP, and will not integrate with JAVA BEAN, virtually no school. We spend more effort on the JSP and BEAN.

Add a few:

We can see that when the ASP + COM, and JSP and BEAN are using component technology, all of the components are compiled first, and the presence of memory, and rapid implementation. Therefore, we always blow the Servlet / JSP first compiled in memory, speed of implementation, there is no advantage.

Conversely, ASP + COM + IIS + NT tightly integrated and should have a greater speed advantage showed. Moreover, ASP + COM + IIS + NT development efficiency is very high, although many BUG. So why use JSP and BEAN? Because JAVA is promising. Microsoft spin-off, the operating system will be independent warlords, the application software developers will find a common development language for development, JAVA domination time comes. If Microsoft is successful spin-off, separate the applications from the company will become the new leader in JAVA. The bulk of the current JAVA SUN and IBM are stagnant, disappointing. Hope that the new company will inject new life. However, the new company is likely to start the old SUN JAVA standards war, the two sides to develop their own standards, influence boast JAVA platform.

In addition, the machine is now faster and faster, JAVA speed disadvantage can be overcome soon.







Recommended links:



Special MO CD 230MB, 540MB, 640MB, 1.3GB



Huang Ching-ASUS court FRIDAY issued reputation infringement in Taiwan



Franke (Heshan) Kitchen Co., Ltd.



3DS MAX of magical engraving



Totem under Ubuntu sound problem playing Rmvb



Best Telephony



AVI to Zune



LiveMotion font production: shadow word



DIVX to iPod



Cisco Crusade Battle With Hewlett-Packard Launched In China



Comments Teaching And Training Tools



Accepted in principle the draft anti-monopoly law by removing sections of Administrative monopoly



MKV to FLV



Five Easy Way To Get Repeat Customers



linux mbr overwritten after installing windows

PowerBuilder objects modified descendants

10.3 descendants of the object changes
Inherit the window is not our purpose ancestors. The purpose of using the inheritance feature is more similar to some common characteristics of the object defined in the ancestor of the object which then passed to future generations inherit the ancestor object access to these common characteristics of the object, after the completion of the work of succession, there is another important task is through modify these objects so that they were descendants of its own unique features to complete the task of future generations of the object itself.

Let's look at an example to illustrate how to implement such changes. First, open a window offspring. Now the window and the window is exactly the same ancestors. Figure 10-6.


Figure 10-6

Ancestors of the window function is to display the database among all the sports stars of the information, we want to modify future generations window, so that the data show only football star.

Select the static text object, right-click on it, pop-up menu, select PROPERTIES command, to modify the content of TEXT column as a "football star." We do not want to delete the button. Figure 10-7.


Figure 10-7

If you want to modify the properties have been ancestors of the window to reset the contents of the menu as long as the choice among the RESET PROPERTIES ED99v reset the Properties command on it. In the data window object we can modify the data window below the script, so that it has new features.


Figure 10-8

In the data window above the right-click, pop-up menu, choose the SCRIPT command, open the script work area, we have seen, when the content of the work area is empty. Figure 10-8.


Figure 10-9

Click SELECT EVENT event selection list box, select the events need to write the script. You can see a list of all events, a small icon on the left is the ancestor event script object which already exists. Figure 10-9.

Select CLICKED click event.


Figure 10-10

At this time, the work area which is still empty, if you want to show the ancestors of the script, you can select the DESIGN menu DISPLAY ANCESTOR SCRIPT show ancestor script command, which could pop up a dialog box, which shows the ancestors of the script, get some tips. Figure 10-10.

Close this dialog box. Scripts and future generations deal with the relationship between the ancestors of the script in two ways, one is overloaded ancestor script, that is to rewrite a script, so replace the ancestors of the corresponding script. For example, here we enter a script:

STRING SYNTAX, SQLSTR, ERRMSG

SQLSTR = "SELECT SOCCER.NAME, SOCCER.AGE, SOCCER.CLUB, SOCCER.NATION" &

+ "FROM SOCCER"

CONNECT USING SQLCA;

SYNTAX = SQLCA.SYNTAXFROMSQL (SQLSTR, "STYLE (TYPE = GRID)", ERRMSG)

dw_1.CREATE (SYNTAX, ERRMSG)

dw_1.Modify ("name.Width = 390")

dw_1.Modify ("age.Width = 140")

dw_1.Modify ("club.Width = 400")

dw_1.Modify ("nation.Width = 260")

dw_1.SetTransObject (SQLCA)

dw_1.RETRIEVE ()

DESIGN window and then choose among the ancestors of the script override OVERRIDE ANCESTOR SCRIPT command on it.

Another is the expansion of ancestral script, which means an increase in the ancestor script based on a script, so that the program is running, the first call to the ancestors of the script, and then the increase in the implementation of our script. If you want to use this approach, you need written script in the following menu choices DESIGN EXTEND ANCESTOR SCRIPT among the ancestors of the script command extension.

Among the POWER BUILDER, can have multi-level inheritance, that is a descendant of an object can have his father, grandfather, or a higher level ancestors. Objects in the script for future generations, we can call any ancestor object which has been written script. For example, call the parent object among CLICKED click event write the script, you can enter the following code like this.

CALL SUPER:: Clicked

Note that this time must be specified SUPER words. The call to a higher level when the ancestors of the script object must be marked ancestor's name, like this:

W_ANCESTOR:: Clicked

We can also call for the ancestors of future generations of objects which included a control object or the object of the event script, for example, the meaning of this script is called the ancestor of the object of a function:

W_ANCESTOR:: Fuction

Understand the content, you master the basic features of the POWER BUILDER inheritance.






Recommended links:



Simple Automation Tools



YUV To AVI



Blog: Beware Of The Computer In The City's "hidden Rules"



Optic Bound Former President Of EA Games Live On Their Own Exclusive Rights To Operate



Chen Zhou reflect years of business success: The greatest scar has not come yet



how to beat THE roulette wheel. try this system



MPEG to MOV



MODELING with UML to note problems



Lead time and queuing time



REVIEW Religion



DV To AVI



Pause slideshow tips



Understanding of the Process of DB2 Universal Database (2)

Lucent and Alcatel merger talks

IDG news exclusively for newspaper companies telecommunications equipment maker Lucent and Alcatel said in a brief statement recently said, as more and more harsh competitive environment, the two companies are exploring the possibility of merger.

Statement wrote: "We can confirm that Lucent and Alcatel are discussing the possibility of the merger on the other, the merger plan according to the market determine the price." The statement also mentioned that does not necessarily guarantee that the two companies reached an agreement.

The statement said: "In the agreement or termination of the discussion, we will not comment further."

If the merger of Alcatel and Lucent, will contribute to the defeat Huawei, ZTE and other competitors. Gartner analyst, said Bertrand Bidaud, Huawei, ZTE and other device manufacturers are looking for from some of the old telecom equipment manufacturer to win market share. He said: "These companies are where the market is not growing, more competitive."

Bidaud said that Lucent and Alcatel merger is significant because the two sides of the customer base there is not much overlap. Moreover, Lucent is very strong in North America, Alcatel in Europe, Asia and other regions more competitive advantage. He said: "In this regard, the two companies merged in the strategic fit."

Current Analysis analyst John Marcus said in the past two or three years, Lucent has been trying to win more business in Europe, "but Lucent, Alcatel and Siemens have been unable to open the gap site."

Marcus said the merger of Alcatel and Lucent might also produce a strong services business, which was the focus of the two companies recently. Lucent in Europe, 30% of revenue comes from professional and managed services available. Alcatel's services business revenue was slightly higher, and its services to focus on IP network transformation, which is Lucent's maintenance and support services play a very useful role.






Recommended links:



Office Suites And Tools Catalogs



How To "control" Yahuo sequels?



OutLook Express Made Easy



AutoCAD Watch A Good Helper



Text OR Document Editors Catalogs



AVI to MPEG4



Unicom 3G Discount Rates Are Not Cut Prices As "fertile" Really Expensive!



With a dinner of examples: MRP OR APS



the turn of cost management abm has it



The "job" into a "job Search" strategy



Agents How to live better?



Hot Geography Education



PPTV Sued The PPS Legislation Grievances To Experts Hope



XviD To MP4



MPEG to 3GP