Referate informatica - referatele de care ai nevoie
Un mic tutorial de PHP
Paginile web ce contin PHP sunt tratate la fel ca şi paginile HTML obişnuite, putând fi create si editate în acelasi mod ca acestea.
De ce este nevoie
Codul PHP este delimitat de coduri de start () ce permit să intri şi să ieşi din "modul PHP" oriunde într-un fisier HTML.
Ex:
Scrierea unui script PHP
Pentru a crea scripturi PHP, majoritatea programat ... Continuare
Date generale despre PHP
PHP a fost conceput în 1994 şi a fost iniţial munca unui singur om, Rasmus Lerdorf. Ulterior a trecut prin trei rescrieri importante pentru a ajunge la produsul actual. PHP este un produs open-source, fiind accesibil accesul la codul sursă, putând fi folosit, modificat si redistribuit în mod gratuit.
Câţiva dintre competitorii principali ai PHP sunt Perl, Microsoft Active ... Continuare
Execuţia unei instrucţiuni SQL
După ce s-a stabilit conexiunea, se pot trimite instrucţiuni SQL către baza de date. API-ul JDBC nu verifică corectitudinea instrucţiunii şi nici apartenenţa ei la un anumit standard SQL, permiţându-se astfel trimiterea chiar de instrucţiuni non-SQL. Programatorul este cel care ştie dacă SGBD-ul interogat suportă interogările pe ca ... Continuare
Stabilirea unei conexiuni către baza de date
Odată ce s-a încărcat un driver, putem să-l folosim pentru stabilirea unei conexiuni către baza de date. O conexiune JDBC este identificată printr-un URL JDBC specific. Sintaxa standard pentru URL-ul unei baze de date este:
jdbc::
Prima parte precizează că pentru stabilirea conexiunii se foloseşte JDBC. Partea de mijloc este un nume de driver valid sau al ... Continuare
Funcţionalitatea managerului de drivere este aceea de a menţine o referinţă către toate obiectele driver disponibile în aplicaţia curentă. Un driver JDBC este înregistrat automat de managerul de drivere atunci când clasa driver este încărcată dinamic. Pentru încărcarea dinamică a unui driver JDBC, folosim metodele Class.forName[10]. Dacă ... Continuare
Interfeţe grafice Java
De la apariţia limbajului Java, bibliotecile de clase care oferă servicii grafice au suferit probabil cele mai mari schimbări în trecerea de la o versiune la alta. Acest lucru se datorează, pe de o parte dificultăţii legate de implementarea noţiunii de portabilitate, pe de altă parte nevoii de a integra mecanismele GUI cu tehnologii apărute şi dezv ... Continuare
Baze de date. Noţiuni de proiectare a bazelor de date relaţionale
La nivelul cel mai general, o bază de date reprezintă o modalitate de stocare a unor informaţii (date) pe un suport extern, cu posibilitatea regăsirii acestora. Uzual, o bază de date este memorată într-unul sau mai multe fişiere.
Aplicaţiile care folosesc baze de date sunt, în general, aplicaţii complexe folosite pentru gestionarea unor informaţ ... Continuare
Java DataBase Connectivity - JDBC
JDBC (Java Database Connectivity) este o interfaţă standard SQL de acces la baze de date[4]. API-ul JDBC conţine un set de clase şi interfeţe pentru funcţii folosite în manipularea bazei de date SQL, cum ar fi conexiuni la baze de date, instrucţiuni SQL sau seturi de rezultate.
Folosind JDBC este uşor de realizat transmiterea secvenţelor SQL c ... Continuare
Tehnologia JAVA
Din multitudinea programelor de dezvoltare a aplicaţiilor software, pentru implementarea interfeţei utilizator s-a ales folosirea unui limbaj de programare orientat obiectual (OOP), limbajul JAVA.
Limbajul de programare Java s-a impus prin calităţi deosebite cum ar fi portabilitate, robusteţe, familiaritate şi nu în ultimul rând simplitate.
Java nu este numai u ... Continuare
Business logic in stored procedures
The business logic is one of the layers that are composite from software system architecture. The business layer is very important to be well defined as it comprises business rules after which the software system functions.
At the beginning, the business logic was made all on client-side, which was so called fat-client; for designing a more robust architecture, the business logic moved from cl ... Continuare
Steps in Defining the Database design
In order to create a proper database design, first the architect of the data base must determine the objectives for the database and also the high-level requirements.
1. The first step that would be helpful is creating a sketch while exposing the logical database design. Based on the input information, tables with their attributes must be defined. Tables which are called also entities, repre ... Continuare
Concepts in relational database design
The relation database design is based on the relational concept approach which describes the information in the manner of predicate logic and truth statements. The relation between this concept and the relational database design is the following: when needing stored information in a database, information about selection criteria must be provided. These are in the form of a logic model, underlyi ... Continuare
Database servers
Starting from the data definition, this term can refer anything that can be stored as the data owner needs to maintain its reference in a specific place, from where he can retrieve, update or delete. For keeping in a well defined manner all this data owners, databases were created, with the purpose of defining an electronic mean through which data can be stored in an organized manner.
Any We ... Continuare
Models in architecting Java Web Applications
The terms for the two architectural designs for Java Web Applications first appeared in the early drafts of the JSP specifications: Model 1 and Model 2.
1.Model 1 architecture: Page-centric
In this architecture, the application is page-centric. The client browser navigates through a series of JSP pages in which any JSP page can employ a JavaBean that performs business operations. However, ... Continuare
Layers architecture for J2EE Applications
Reviewing the software system architecture, layers of an application are separated logic parts that belong to the application. The same layers stands also in the J2EE Application. The description of layers, now taking into consideration the web components from J2EE platform, is presented below:
o Presentation layer: This layer is made up of Java Server Pages (JSP) which are basically HTML file ... Continuare
Tomcat Servelt Container
Through all the servlet containers on the market today the Tomcat servlet/JSP container is recognized as the official one. Originally designed by Sun Microsystems, Tomcat source code was handed over to the Apache Software Foundation in October 1999. Here, Tomcat was included as part of the Jakarta Project, one of the projects of the Apache Software Foundation.
Tomcat by actually a web server ... Continuare
Java Server Pages
According to Sun\ s web site, "JSP technology is an extension of the servlet technology created to support authoring of HTML and XML pages". Java Server pages appeared as the technology of using servlets showed out some disadvantages. One of the disadvantages is that for a simple Http response page, the code was quite large because it had to declare parameters, methods, writing HTML tags, etc. ... Continuare
Servlet Application Architecture
The basic architecture of an application that involves processing of servlets, and thus, implies the existence of the servlet container, which communicates with the clients requests by the HTTP protocol. The servlet container it will be replaced by a JSP container in the context of JSP page files usage. Their role is the same.
There are two configurations for the architecture of a servlet app ... Continuare
J2EE web components
2.1 Servlet
The Java Servlet API is one of the most important technologies included in the J2EE platform, providing utility in building dynamic content. It is directly related to another successful technology, Java Server Pages. Regarding the approaches, the java servlet is similar as role and objectives with other technologies like ASP.
A servlet is a java class that can be loaded dynamica ... Continuare
J2EE platform
For developing multi-tier application as web-applications, the software architect needs a reliable and robust platform to build the system on. One of the most famous and used platforms in nowadays web-application is the Java platform J2EE. The name of the platform comes from Platform Java 2 Enterprise Edition.
J2EE is a programming platform, designed for developing and running distributed multi ... Continuare
