High Level Programming Language Of Java Computer Science Essay Example

where a program can be compiled into byte codes using a Java compiler on any platform and then executed on any implementation of the Java VM. Consequently, a Java program developed in the Java programming language is capable of running on diverse operating systems such as Windows 2000, Solaris workstations, or iMacs with a Java VM installed.

Description: helloWorld

Fig: 3.3.2

The platform for a program refers to the hardware or software environment it is designed to run on. Application developers create programs that cater to specific user requirements, whether it serves one user at a time, multiple users simultaneously, or users in different locations. In Java, this platform tackles common challenges faced by developers and provides different technology options based on user needs. The Java platform encompasses two main components: the Java runtime environment (JRE) and the Java Development Kit (JDK). The JRE enables an operating system to execute Java programs on a computer, while the JDK comprises tools utilized by programmers during application development in Java.

There are multiple versions of the Java platform, each with its own set of Java API's for developing different applications. These versions include Java Standard edition (Java SE), Java Enterprise Edition (Java EE), and Java Micro Edition.

Java SE is mainly used for creating desktop applications and applets that cater to a small user base.

In contrast, Java EE is specifically designed for complex applications and is well-suited for medium to large businesses. It operates as a server-based application capable of handling multiple users simultaneously.

Lastly, Java Micro Edition is implemented on mobile and embedded devices such as PDA's, printers, tuner boxes, and cell phones.

The mentioned platforms such as Windows 2000, Linux,

Solaris, and MacOS are well-known examples. Unlike most platforms that require a combination of operating system and hardware, the Java platform stands out for being a software-only platform compatible with different hardware-based platforms.

Java platform consists of two components:

The Java Virtual Machine, also known as the Java VM

The Java Application Programming Interface (Java API)

The Java VM has already been introduced in previous sections as the foundation for the Java platform and is adaptable to different hardware-based platforms.

The Java API is a collection of pre-built software components, including graphical user interface (GUI) widgets. These components are organized into packages, which are libraries that contain related classes and interfaces.

In this section, we will outline the capabilities and functionalities of Java Technology.

The Java API offers certain packages that provide functionality. This section outlines the features provided by these packages.

The following diagram showcases a program in action on the Java platform, highlighting how both the Java API and virtual machine safeguard the program from underlying hardware.

Description: g3

Fig: 3.3.3

Native code is executed and compiled on a specific hardware platform, whereas the Java platform has no limitations on hardware. Generally, native code processing is faster than Java processing. However, it is possible to attain comparable performance to native code without compromising portability by utilizing intelligent compilers, optimized interpreters, and just-in-time byte code compilers.

The Java programming language has two main types of programs: applets and applications. Understanding applets in their context is crucial for easily and reliably finding information about them online. Applets are programs specifically designed to run faster on a Java-enabled browser by adhering to certain conventions. However, the capabilities of Java programming extend beyond creating entertaining web-based applets.

It is a robust software platform that supports various types of programs. By offering development tools, application programming interfaces (APIs), deployment technologies, user interface toolkits, and integration libraries through its extensive API, Java provides all the necessary resources for compiling, running, monitoring debugging, and documenting applications.

The API served as the primary source of essential functionality by offering a large collection of useful classes readily available for implementation in user applications. The API's broad scope allowed for the inclusion of various classes necessary for creating applets, and these applets were categorized to facilitate communication with the applet contexts. Additionally, the API facilitated the extension of applications to end users through a standardized mechanism. To simplify the creation of complex Graphical User Interfaces, user interface toolkits like Swing ; Java toolkits were utilized. Integration libraries were also employed to facilitate easy access to databases and collaboration with remote objects.

An application on the Java platform is a standalone program that includes various types, such as "server" and "servlet". The server type serves and supports clients on a network, like Web servers, proxy servers, mail servers, and print servers. Conversely, servlets function similarly to applets but work on the server side. They are frequently utilized for building interactive web applications and often serve as substitutes for CGI scripts.

Servlets are runtime extensions of applications, similar to applets. However, unlike applets, servlets do not run in browsers. Instead, they run within Java Web servers and configure or tailor the server.

The API supports multiple programs through the use of software component packages that provide a wide range of options to improve application functionality. Each complete Java platform implementation includes the following

features:

The basics include objects, strings, threads, numbers, input and output, data structures, system properties, date and time, and more.

The set of conventions used by applets are applets.

Networking involves utilizing various components such as URLs, TCP sockets (Transmission Control Protocol), UDP sockets (User Datagram Protocol), and IP addresses (Internet Protocol).

Internationalization involves writing programs that can be accessible to users worldwide. These programs can seamlessly adjust to specific locales, including displaying content in the appropriate language based on user preferences.

Security encompasses both low level and high level aspects, such as electronic signatures, management of public and private keys, access control, and certificates.

Software components, also referred to as JavaBeans, have the capability to seamlessly integrate into current component architectures.

Lightweight persistence and communication through Remote Method Invocation (RMI) are enabled by object serialization.

JDBCTM provides consistent access to various relational databases.

The Java platform offers a wide range of APIs that cover various functionalities such as graphics for 2D and 3D, accessibility features, server capabilities, collaboration tools, telephony functions, speech recognition support, animation tools, and more.

The figure included in the Java 2 SDK provides a depiction of what is included. The description of the figure is "gs5".

Fig: 3.3.4

Although it does not promise fame, wealth, or employment, Java technology is a valuable resource for learning the Java programming language. It is widely accepted and offers numerous important features that make understanding and implementing Java technology simpler and more efficient compared to other languages. With Java, users can create various dynamic, secure, and autonomous applications. This has led to a rapid expansion of its user base. Moreover, there is a belief that Java technology improves the effectiveness of various functions and actions.

Java

is a user-friendly programming language that is easy to write and understand. It does not require explicit management of pointers or memory, allowing for the creation of secure applications without interruptions. Moreover, Java is a robust object-oriented language that particularly appeals to programmers already familiar with C or C++.

The analysis of program metrics, such as class counts and method counts, reveals that a Java program can be significantly smaller than a corresponding C++ program by a factor of four. This difference in size is due to the implementation of various Object Oriented Programming (OOP) principles, including inheritance, encapsulation, and polymorphism during operations. These differences distinguish Java from languages like C and C++.

The Java programming language promotes better coding practices and prevents memory leaks with its garbage collection. It also provides object orientation, a JavaBeans component architecture, and a versatile API that enables code reuse and reduces bugs.

Develop programs faster by writing code at a quicker pace, about twice as fast as C++, due to fewer lines of code and a simpler programming language.

To ensure portability in your program, it is recommended to refrain from using libraries written in different languages. By leveraging the resources provided by the 100% Pure Java Product Certification Program, including process manuals, white papers, brochures, and other online materials, you can successfully eliminate dependence on specific platforms.

Write once, run anywhere: The reason why 100% Pure Java programs can run consistently on any Java platform is because they are compiled into machine-independent byte codes.

Upgrade applets easily from a central server and take advantage of the feature of allowing new classes to be loaded "on the fly," without recompiling the entire program to

distribute software more easily.

The Java programming language enables communication with remote objects distributed over a network. Its libraries include the necessary resources for developing network applications, such as RMI and CORBA. These libraries allow primary data types to be treated as objects through the use of covering classes, making Java a fully object-oriented language. In Java, a class is considered the fundamental unit, and objects adhere to the prototypes defined by their respective classes.

Java applications offer increased reliability through various means. These include compile time checking, which allows for early detection of bugs; run time checking; elimination of pointers that can lead to memory corruption or unnecessary memory access; automatic waste/garbage collection management to free unused memory; and error handling to address issues as they occur, among other benefits.

Microsoft Open Database Connectivity (ODBC) is a programming interface that provides a standard for application developers and database systems providers. Before ODBC, programmers had to use specific languages for each database they wanted to connect with. With ODBC, the choice of the database system is no longer significant in terms of coding. This allows application developers to focus on more important aspects of their work, rather than dealing with syntax changes when switching databases due to business needs.

Through the ODBC Administrator in Control Panel, one can select the database that is linked to a data source. An ODBC application program is designed to utilize this selected database. Think of an ODBC data source as a labeled door leading to a specific database. For instance, the Sales Figures data source may connect to a SQL Server database, while the Accounts Payable data source could be associated with an

Access database. The data source refers to a physical database that can be located anywhere on the LAN.

On a user's system, Windows 95 does not automatically install the ODBC system files. Instead, these files are installed when the user sets up a separate database application like SQL Server Client or Visual Basic 4.0.

The Control Panel's ODBC icon is associated with a file named ODBCINST.DLL. Users can also manage their ODBC data sources using a stand-alone program called ODBCADM.EXE.

This program exists in both 16-bit and 32-bit versions, each maintaining its own list of ODBC data sources.

From a programming perspective, the advantage of ODBC is that applications can use the same function calls to interact with any data source, regardless of the database vendor.

This means that the application's source code remains unchanged whether it connects to Oracle or SQL Server.

Currently, there are only two examples that can be used. There are multiple ODBC drivers available for popular database systems and for converting Excel spreadsheets and plain text files into various data sources. The operating system depends on the Registry information created by ODBC Administrator to identify the necessary low-level ODBC drivers needed to communicate with the data source (e.g. Oracle or SQL Server). The implementation of these drivers is not visible to the ODBC application program. In a client/server environment, the ODBC API handles many network complications for the application programmer.

The advantages of ODBC are many, leading users to suspect that there must be a drawback. The only downside of ODBC is its lack of efficiency compared to direct communication with the native database interface. There have been critics of ODBC who argue that it is too

slow. However, Microsoft has consistently shown that driver software quality is the crucial factor in performance. We agree with this belief. Recently, the availability of high-quality ODBC drivers has greatly improved. Additionally, the criticism about performance is similar to those who claimed that compilers would never match the speed of pure assembly language.

Maybe not, but the compiler (or ODBC) enables users to create more efficient programs, leading to faster programming completion. This accelerated compilation of programs or applications contributes to the ongoing improvement in computer speed over time.

JDBC, an abbreviation for Java Database Connectivity, was developed by Sun Microsystems to establish a uniform approach for Java programs to communicate with databases. JDBC encompasses the definition of methods and protocols enabling users to access their databases while conducting various operations like data manipulation and updates. The simplicity and ease of implementation are notable advantages of utilizing JDBC. Additionally, it provides robust security measures and can be automatically downloaded. Furthermore, JDBC leverages the advantages offered by the Java programming language.

JDBC is specifically designed for relational databases. The JDBC-ODBC bridge enables connections to any other ODBC accessible data source within the JVM host environment. JDBC offers a reliable interface for accessing SQL databases and supports multiple RDBMSs through plug-in database connectivity modules or drivers. To ensure JDBC compatibility, database vendors must provide drivers for each platform that the application will run on.

Previously mentioned, ODBC was utilized as the basis for JDBC in order to encourage greater acceptance. Various platforms extensively support ODBC. By building JDBC on top of ODBC, vendors can save time and effort by bypassing the necessity of developing a completely new connectivity solution for their

JDBC drivers.

The JDBC technology was initially introduced in March 1996 and underwent a 90-day public review period until June 8, 1996. After considering user feedback, the final version of the JDBC v1.0 specification was released shortly after. The subsequent section offers sufficient information on JDBC's purpose and usage, though not extensively.

The JDBC API enables the dynamic loading and registration of necessary Java packages with the JDBC driver manager, allowing multiple applications to coexist and be utilized by a single application. The driver manager acts as a connection factory for generating different forms of JDBC connections.

There are several types of drivers for JDBC including client-side adapters that are already installed on the client system and not on the server. These drivers convert requests from Java programs into a protocol that can be understood by the DBMS. The JDBC drivers are classified as commercial or free and are compatible with most relational database servers. These drivers typically fall into one of these categories:

Type 1 refers to the method of calling the native code of the locally available ODBC driver.