Transgression forswear-maintaining centralized database Essay Example

would download executable programs from time to time. However, these users exercised caution by scanning the programs for viruses before running them and had worries about infecting their systems with viruses. There is also another type of harmful program that poses a threat by gathering personal information like credit card numbers, bank account balances, and passwords. Java addresses both concerns through its provision of a "firewall" which acts as a protective barrier between your computer and a network application.

Java applets can be safely downloaded using a Java-compatible Web browser without worrying about virus infection or malicious intent. The ability to have portable executable code is crucial in enabling dynamic downloads of programs on different Internet-connected platforms. An impressive aspect of Java is its ability to address both security and portability concerns effectively through the generation of Byte code by the Java compiler.

Byte code is a set of optimized instructions made for execution by the Java Virtual Machine (OVUM), which acts as the runtime system for Java. By converting a Java program into byte code, it becomes easier to run the program in various environments. This is possible because any Java program can be executed on a specific system as long as it has the necessary runtime package. Although Java was initially intended for interpretation, there are no technical limitations preventing byte code from being compiled into native code instantly.

Sun has finished creating the Just In Time (JIT) compiler for bytecode in Java. The JIT compiler converts bytecode into executable code as it is needed during real-time execution. Due to certain runtime checks that can only be done during execution, it is not

feasible to compile an entire Java program at once. Instead, the JIT compiler compiles code on-demand during execution. Moreover, apart from the language itself, there is also the Java Virtual Machine (JVM), which plays a vital role in Java technology.

The virtual machine, found in a web browser or operating system, is in charge of loading and validating Java code. To ensure that the compiled code does not harm the hosting machine, a class loader is called upon during this loading process to perform byte code verification. This verification step is essential for successfully compiling and running Java code since it generates byte codes that are then executed.

The Java source code is stored in a Java file and processed by a Java compiler named Java. The compiler generates a Class file that contains the byte code. This Class file is then loaded into the execution environment called the Java virtual machine, either over the network or locally on your machine. The virtual machine interprets and executes the byte code. Fig 2.1 depicts the development process of a JAVA Program.

Java architecture provides a portable, robust, and high-performing development environment.

Java is a dynamic system that achieves portability by compiling byte codes for the Java Virtual Machine (JVM) and interpreting them on various platforms using the run-time environment. When code is compiled in Java, it produces machine code known as byte code for the JVM. The primary objective of Java is to address the problem of portability, allowing code written and compiled for one machine to be interpreted on any machine, regardless of its location.

The Java Virtual Machine is a machine that can compile and

interpret Java source code. During runtime, the Java interpreter deceives the byte code file into believing it is being executed on a Java Virtual Machine. In reality, this machine could be an Intel Pentium running Windows 95 or a Sun workstation running Solaris, or even an Apple Macintosh with its operating system. All of these machines are capable of receiving code from any computer via the internet and executing applets. One key aspect of Java is its simplicity, as it was designed to be easily learned and effectively utilized by professional programmers.

Java is easier for experienced C++ programmers to learn because it shares the syntax and object-oriented features of C++. It simplifies complex concepts from C++ and makes them more accessible. Java also provides a limited number of distinct methods for completing specific tasks.

Unlike other programming languages, Java was intentionally designed to be incompatible, giving developers the freedom to innovate. This approach resulted in a practical and streamlined treatment of objects.

The Java object model is simple and can be easily extended. Primitive types, like integers, are optimized for performance and not treated as objects. The design of the Java language prioritizes robustness to ensure compatibility with various web platforms. This requires Java programs to run consistently on different systems. Java is a statically typed language which means that errors in your code are checked during both compilation and runtime. Moreover, Java incorporates automatic memory management to eliminate manual memory handling and avoid memory leaks.

Handling all runtime errors within the code is crucial for ensuring a well-written Java program. HTML, which is used on the World Wide Web (WWW) to generate web pages

with text, graphics, and hyperlinks, is not a programming language itself. Instead, it implements ISO Standard 8879 known as SUMS (Standard Generalized Markup Language). This language was designed specifically for hypertext and later adapted for web usage. Hypertext allows users to have non-linear reading experiences and easily navigate from one point to another.

HTML is a flexible language that enables us to navigate information according to our preferences. It comprises elements enclosed in special characters, dictating the display of text and other items. Hyperlinks, indicated by highlighted or emphasized words, can connect to other documents or sections within the same document. HTML allows for displaying different types of documents on various geographic locations, ensuring compatibility with any platform or desktop.

are codes that enhance the visual appearance of a document. They can be used to improve the presentation with graphics, fonts, different sizes, color, etc. Everything else in the document is considered part of it. HTML has several advantages: its small size makes it easy to send over the internet as it doesn't contain formatted information; it is platform independent and its tags are not case-sensitive; it is also easy to learn and code, even for novice programmers. HTML is supported on almost every browser.

Widely used and established on almost every website, if not all websites, the basic include creating hypertext links, formatting text as bold, and containing all tags and text in the HTML document. They also define terms, create definition lists, format text with a particular font, enclose a fill-out form, and define a particular frame in a set of frames. Additionally, they create headings of different levels, align text

to center, and contain tags that specify information about a document. Other provide meta-information about a document and contain client-side or server-side script.

The <p> and </p> enclose the following text: "Contains all Creates a table. . Indicates table data in a table. Designates a table row. 2. 4 JAVASCRIPT JavaScript is a script-based programming language that was developed by Netscape Communication Corporation. JavaScript was originally called Live Script and renamed as JavaScript to indicate its relationship with Java. JavaScript supports the development of both client and server components of Web-based applications. On the client side, it can be used to write programs that are executed by a Web browser within the context of a Web page."

JavaScript is a widely used programming language for both server-side and client-side purposes. It can be used on the server side to process data from a Web browser and update the display, but its main usage is for client-side programming because it is well-supported by browsers. Learning JavaScript is easy as it has similarities with HTML, and it can be added to HTML documents using scripting tags. It allows manipulation of form contents and performing various tasks like calculations.

The text highlights the different ways JavaScript can enhance browser functionality. These include adding scrolling or changing messages to the browser's status line, animating or rotating images on mouseover, displaying unique content for different browsers, and detecting necessary plug-ins. JavaScript is capable of creating complete applications as well. Although both JavaScript and Java are programming languages, they have distinct differences. For instance, Java applets are displayed within a box on the web document while JavaScript has direct

impact on any part of the web document.

Discussing the differences between JavaScript and Java, their distinct uses are highlighted. JavaScript is primarily used for simple applications and adding interactivity to web pages, while Java is more suitable for complex applications. However, despite these disparities, both languages can be combined to leverage their respective advantages.

JavaScript has the advantage of being a versatile scripting language that can be used for server-side and client-side scripting. It is also the default scripting language for all browsers.

In contrast, Java utilizes JDBC (Java Database Connectivity) technology to manipulate data stored in databases through Java programs. JDBC consists of four components: the JDBC API, the JDBC Driver Manager, the JDBC-rest suite, and the JDBC-ODBC Bridge.

The JDBC API serves as an industry standard for connecting Java with various databases and provides a way to access relational databases using the Java programming language. Its "Write Once, Run Anywhere" (WORD) capabilities allow users to execute SQL statements, retrieve results, update data, and access it from any location within a network.

In addition to its compatibility with diverse databases, thanks to its versatility provided by the JDBC API technology users can even access other tabular data sources such as spreadsheets or flat files regardless of environment heterogeneity.

The JDBC application programming interface is a crucial part of the Java platform, which includes both Java Standard Edition (Java SE) and Java Enterprise Edition (Java EE). It comprises four primary interfaces and is divided into two packages: Java.SQL and Java.SQL.Java SE, as well as Java SQL.Java E. These packages encompass both the Java SE and Java EE platforms. Furthermore, the JDBC Driver Manager, an essential class, defines objects that

establish connections between Java applications and JDBC drivers.

The Driver Manager is a crucial component of the JDBC architecture as it effectively manages different types of JDBC database drivers utilized by an application. Its primary role is to load all available drivers in the system and choose the most suitable one for establishing a database connection. Moreover, it aids in selecting the optimal driver from those already loaded when connecting to a newly opened database.

The JDBC Test Suite is designed to check if the user's program can function correctly with JDBC drivers. It is especially helpful for testing these drivers during the testing phase to ensure they meet the requirements of Java Platform Enterprise Edition (IEEE). The JDBC-ODBC Bridge, also known as the JDBC type 1 driver, uses the ODBC driver to establish a database connection. It converts JDBC method calls into ODBC function calls.

The Bridge utilizes Jdbc to connect to any database that has an Odbc driver. The Bridge is implemented as the sun. ]db. ODBC Java package, which includes a native library for accessing ODBC. The JDBC Architecture includes database connections, SQL statements, Result Set, Database metadata, Prepared statements, Binary Large Objects (BLOBS), Character Large Objects (Slobs), Callable statements, and Database drivers. The JDBC API uses a Driver Manager and database-specific drivers to ensure seamless connectivity to different databases.

The JDBC driver manager guarantees that the appropriate driver is employed to access each data source. The Driver Manager supports several concurrent drivers connected to various databases. Figure: Layers of the JDBC Architecture Fig 2. 3 JDBC Architecture depicts the position of the driver manager in relation to the JDBC drivers and the

servile. A JDBC driver converts standard JDBC calls into a network or database protocol or a call to a database library API, enabling communication with the database.

This translation layer offers database independence for JDBC applications. If the back-end database is changed, only the JDBC driver needs to be replaced with minimal code modifications. There are four distinct types of JDBC drivers. 2. 5. 3 JDBC Driver and Its Types Type 1 JDBC-ODBC Bridge: Type 1 drivers serve as a "driver" between JDBC and another database connectivity mechanism like ODBC. The JDBC-ODBC bridge provides JDBC access by utilizing most standard ODBC drivers. This driver is included in the Java 2 SD within the sun. ]db. ODBC package.

This driver converts Java statements to Jdbc statements by calling the ODBC through the JDBC-ODBC Bridge. The database then executes the query. However, this driver has limitations for many applications as shown in Type 1 JDBC Architecture Fig 2. 4.
Type 1 JDBC Architecture Type 2 Java to Native API: Type 2 drivers utilize the Java Native Interface ON') to make calls to local database library API. This driver converts JDBC calls into database-specific calls for various databases like SQL, ORACLE, etc. It directly communicates with the database server.

The connection to the database requires native code. Type 2 drivers are typically faster than Type 1 drivers. Similar to Type 1 drivers, Type 2 drivers need native database client libraries to be installed and configured on the client machine. Type 2 JDBC Architecture Fig 2. 5 Type 2 JDBC Architecture depicts Type 3 Java to Network Protocol or All-Java Driver: Type 3 drivers are purely Java-based drivers

that employ a proprietary network protocol to communicate with JDBC middleware on the server. The middleware then converts the network protocol into database-specific function calls.

The most flexible JDBC solution is Type 3 drivers because they can connect to various databases on the back end without requiring native database libraries on the client. They also have the advantage of being able to be deployed over the Internet without any need for client installation. The Type 3 JDBC Architecture in Fig 2.6 illustrates how Java utilizes JDBC statements to execute SQL statements on databases. In contrast, Type 4 drivers are pure Java drivers that directly communicate with the database using a proprietary database protocol, such as Oracle's SQL*Net.

Type 4 drivers, like Type 3 drivers, do not require native database libraries and can be used over the Internet without client installation. However, a drawback of Type 4 drivers is their specificity to a particular database. Unlike Type 3 drivers, if you change your back-end database, you may need to buy and deploy a new Type 4 driver (although some manufacturers offer free Type 4 drivers). Nevertheless, because Type drivers directly communicate with the database engine instead of using middleware or a native library, they are generally the fastest JDBC drivers.

This driver aims to directly convert Java statements into SQL statements. Figure 2.7 shows the Type 4 JDBC Architecture that relates to this driver. Therefore, you might be interested in knowing which driver type is appropriate for your application. The answer depends on your project's specific requirements. If you can't or don't want to install and configure software on every client, using Type 3 or Type

4 drivers may result in excessive costs for you. In such a situation, Type 1 and Type 2 drivers could be more attractive options as they are usually available free of charge.

When considering a particular application, the choice between Type 3 or Type driver often comes down to price. It is important to consider the benefits of flexibility and interoperability versus performance. Type 3 drivers allow applications to access different databases seamlessly, while Type 4 drivers generally offer better performance. Similar to Type 1 and Type 2 drivers, Type 4 drivers may be available for free from the database manufacturer. Furthermore, Java Server Pages (JSP) is a powerful technology for creating and maintaining dynamic-content web pages.

Java Server Pages (JSP) offers portability, open standards, and a mature re-usable component model. It allows for the separation of content generation from presentation, making maintenance easier and allowing team members to focus on their specific areas of expertise. JSP files can run on any web server or web-enabled application server that supports them. The JSP engine recognizes, translates, and manages the lifecycle and interaction components of JSP. Additionally, JSP architecture allows for the inclusion of reusable Java components and the embedding of a scripting language directly into the JSP file.

The supported components currently include Java Beans and Servest. When processing a Java Server Pages file, it is essentially treated as an HTML document with JSP scripting or tags. The Java Server Pages file is given a JSP extension on the server side. Before the page is served, the Java Server Pages syntax is parsed and processed into a Servile on the server side. This Servile generates

actual content in plain HTML to be sent back to the client. There are at least two different ways to access a Java Server Pages file.

A Java Server Page (JSP) receives a client's request. In this situation, the page utilizes reusable Java Bean components to perform specific computations, such as accessing a database. The results of these computations, known as result sets, are stored within the Bean as properties. The page uses these Beans to generate dynamic content and present it to the client. Additionally, the page may include any valid Java code. The architecture of JSP promotes the separation of content and presentation.

The execution of a JSP application involves several steps. First, the client sends a request to the web server for a JSP file. This request includes the name of the ISP file within the form tag of an HTML page. The server receives this request and forwards it to the JSP engine.
The JSP engine, known as Jawbreakers, is responsible for processing JSP tags. It converts these tags into a Servile program, which is then stored on the server side.

The Servile is loaded in the memory and executed, with the result given back to the Jawbreakers. Afterwards, it is transferred back to the client. 2.6.2 Java Beans: It is possible to easily assemble a computer or fan by selecting various components from different vendors. For example, we can use a screw from company one to attach the Mother board to the cabinet, as they are manufactured to a standard size.

Different software companies have proposed various component technologies to enhance the process of software development. Examples of these technologies include

Java Bean component tech and EJB component tech from Java Soft, Microsoft COM, and the BONO component model. Java Bean and EJB are distinct specifications from Java Soft. EJB is commonly used for implementing business logic on the server side. While many developers assume that Java Bean components are only for developing GUI components and can only be used on the client side, it is important to note that we can develop any kind of software using the Java Bean standard, whether GUI or non-GUI.

Both the client and server sides can utilize Java Bean. The Java Bean standard is followed by AWT and JEFF components, which states that a Bean component can possess a collection of properties, events, and any number of additional methods. Properties can be either read-write or read-only. If a property is read-write, it must have set and get methods (six in the case of Boolean).

To support the properties (I) name, (II) email, and (III) age according to the Java bean standard, we need to write the code as follows:

public class Serbian {
String name;
String email;
int age;

public void sequestrate(String value) {
name = value;
}

public void estimate(String value) {
email = value;
}

public void stage(int value) {
age = value;
}

public String stammering() {
return name;
}

public String Guatemala() {
return email;
}

public int stage() {
return age;
}
}

Java Beans, like Cobnuts, support events by providing methods with specific naming patterns. Additionally, apart from developing a Java bean class, we can also provide a Beanpole class. This class can provide information about properties, information, and the icon that represents our bean (IV). According to the JSP model (Fig. 8), we can develop the application where the presentation logic is implemented in the JSP page and the business logic is implemented as part of the Java bean. This model helps in separating the presentation and business logic.

For a large scale projects, it is recommended to use modems (MFC) instead of models. The Struts framework is built on the foundation of model 2.7. Struts is renowned for its strong architecture and is utilized for both small and large software projects. It is an open source framework used for developing JEEZ web applications using the Model View Controller (MFC) design pattern. Struts leverages and expands the Java Servile API to promote the adoption of MFC architecture.