What Is a Servlet?

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4 min readApr 19, 2022

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A servlet is any Java class that can be invoked and executed on a server, usually on behalf of a client. A servlet works on the server, while an applet works on the client

A HTTP servlet is a Java class that handles a HTTP solicitation and conveys a HTTP reaction. HTTP servlets live on a HTTP server and should broaden the JavaSoft javax.servlet.http.Http Servlet Class so they can run in a conventional servlet motor structure.

A few benefits of utilizing HTTP servlets are:

  • They are written in a very much shaped, and assembled language (Java), so are more hearty than “deciphered” scripts.
  • They are an indispensable piece of the HTTP server that upholds them.
  • They can be safeguarded by the hearty security of the server, dissimilar to some CGI scripts that are risky.
  • They connect with the HTTP demand through a very much evolved automatic point of interaction, as are simpler to compose and less inclined to blunders.

How Servlets Work with Jolt

With Jolt servlet network, any conventional HTTP servlet permits you to exploit the Jolt highlights. Shock servlets handle HTTP demands utilizing the accompanying Jolt classes:

  • ServletDataSet
  • ServletPoolManagerConfig
  • ServletResult
  • ServletSessionPool
  • ServletSessionPoolManager

The Jolt Servlet Connectivity Classes

Following are depictions of the Jolt servlet network classes.

ServletDataSet

This class contains information components that address the info and result boundaries of an Oracle Tuxedo administration. It gives a strategy to import the HTML field names and values from a javax.servlet.http.HttpServletRequest object.

ServletPoolManagerConfig

This class is the startup class for a Jolt Session Pool Manager and at least one related Jolt meeting pools. It makes the meeting pool supervisor if necessary and starts a meeting pool with a base number of meetings. Shock Session Pool Manager inside monitors at least one named meeting pools.

This class is gotten from bea.jolt.pool.PoolManagerConfig and permits the guest to pass a Properties or Hashtable item to the static startup() strategy to make a meeting pool and the static getSessionPoolManager() technique to get the meeting pool supervisor of bea.jolt.pool.servlet.ServletSessionPoolManager class.

ServletResult

This class gives strategies to recover each field in a ServletResult object as a String.

ServletSessionPool

This class gives a meeting pool to use in a Java servlet. A meeting pool addresses at least one associations (meetings) to an Oracle Tuxedo framework. This class gives call strategies that knowledge input boundaries for an Oracle Tuxedo administration as a javax.servlet.http.HttpServletRequest object.

ServletSessionPoolManager

This class is a servlet-explicit meeting pool director. It deals with an assortment of at least one meeting pools of class ServletSessionPool. This class gives techniques that are utilized to make both the ServletSessionPoolManager itself and the meeting pools that it contains. These techniques are essential for the regulatory API for a meeting pool.

Composing and Registering HTTP Servlets

Prior to composing and enrolling HTTP servlets, you should initially import the bundles that help Jolt servlet network (jolt.jar, joltjse.jar, servlet.jar). HTTP servlets should expand javax.servlet.http.HttpServlet. After you compose your HTTP servlets, you register them with a Web server that upholds nonexclusive servlets. Your custom servlets are dealt with precisely like the standard HTTP servlets that give the HTTP capacities.

Every HTTP servlet is enrolled against a particular URL design, with the goal that while a matching URL is mentioned, the relating servlet is called upon to deal with the solicitation.

Allude to the documentation for your specific Web server for directions on the best way to enlist servlets.

Shock Servlet Connectivity Sample

The Jolt programming incorporates three example applications that show servlet network utilizing the Jolt servlet classes. The three examples are:

  • SimpApp Sample
  • BankApp Sample
  • Administrator Sample

Allude to these examples to see code instances of how to utilize the Jolt servlet classes in your own servlets.

Seeing the Sample Servlet Applications

To see the code for the Jolt test applications, you want to introduce the Jolt API client classes (generally picked as a choice while introducing Jolt). When the classes are introduced in your index of decision, explore to the accompanying catalog to see the example application records:

\udataobj\jolt\examples\servlet

To see the example code, utilize a content tool, for example, Microsoft Notepad to open the Java records for each example application. SimpApp Sample

An example application named simpapp is incorporated with Jolt. The simpapp application represents how the servlet involves Servlet Connectivity for Oracle Tuxedo. The accompanying servlet errands are outlined by the SimpApp test:

  • Utilizing a property document to make a meeting pool
  • Getting the meeting pool chief
  • Recovering the meeting pool by name
  • Summoning an Oracle Tuxedo administration
  • Handling the outcome set

This model shows how a servlet can associate with Oracle Tuxedo and endless supply of its administrations; it ought to be conjured from the simpapp.html record. The servlet makes a meeting pool administrator at instatement, which is utilized to acquire a meeting when the doPost() technique is conjured. This meeting is utilized to associate with a help in Oracle Tuxedo with a name depicted by the posted “SVCNAME” contention. In this model the assistance is designated “TOUPPER”, which translates the posted “STRING” contention text into capitalized, and returns the outcome to the client program inside some produced HTML.

Note: The WebLogic Server is utilized in this model. Necessities for Running the SimpApp Sample

The necessities for running the SimpApp test are:

Any Web application server with Servlet JSDK 1.1 or above

  • Prophet Tuxedo 8.0 or later with SimpApp test running
  • Prophet Jolt

Administrator Sample

The Admin test application delineates the accompanying servlet assignments:

  • Utilizing the regulatory API to control the meeting pools
  • Recovering the insights through PageCompiledServlet in Servlet Connectivity for Oracle Tuxedo Prerequisites for Running the Admin Sample

Following are the prerequisites for running the Admin test:

  • Any Web application server with Servlet JSDK 1.1 or above
  • Prophet Jolt

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