
Java is a high-level programming language and object-oriented Java program is composed of parts called classes. Class consists of methods that do the work and restore the information after doing its job. Java programmers take advantage of a collection of many classes in the Java class libraries, called the Java Application Programming Interface (API). These classes are organized into a group called the package (package). Java API has provided sufficient functionality to create sophisticated applications and applets. So there are two things that must be studied in Java, namely learning the Java language and how to use classes in the Java API.Class is the only way of stating the execution of the program, there is no other way. In the Java program to compile javac Java source code files into bytecode classes.Source code files have extension *. java. Javac bytecode compiler produces class files with the extension *. class. Interpreter is the main module used by the Java system and Java applications to run Java bytecode programs.
Some of the advantages of java java is a simple language. Java is designed to be easily learned and used effectively. Java does not provide complex features high-level programming language, and many programming jobs are beginning to be done manually, now replaced Java is done automatically like memory deallocation. For programmers who are familiar with the language C + + will quickly learn the composition of the Java language but must be vigilant because probably the Java take direction (semantiks) are different than C + +.
Java is an object-oriented language (OOP) is a powerful way of organizing and software development. In OOP, computer programs as a group of interacting objects.OOP concise description is organizing the program as a collection of components, called objects. These objects exist independently, have rules to communicate with other objects and to instruct other objects in order to request specific information or to request other objects to strings. The class acts as well as the type of module. As a type it at the time of the road, the program creates objects that are instant-instant class. Classes can inherit another class. Java does not allow multiple inheritance multiple inheritance, but complete with the facility needs a more elegant interface.
All objects must be declared first be programmed before use. This is an advantage of Java Statically typed. This coercion enables the Java compiler to determine and report the occurrence of conflict (incompatible) type which is the initial barricades to prevent unnecessary errors (such as subtracting an integer variable with a variable of type string). Prevention as early as might be expected to produce a clean program.Another goodness of this feature is more program code can be optimized to produce high-performance program.
Java uses three-tier security model (three-layer security model) to protect the system from untrusted Java code. First, the bytecode verifier reads bytecodes before bytecode is run and guarantees to meet the basic rules of the Java language.Second, the class loader handles the loading of Java classes into the runtime interpreter. Third, the security manager to handle application-level security to control whether the program has access to resources such as file systems, network ports, external processes and the window system.
Platform independence is the ability of the program to work on different operating systems. Java language is a language with a perfect platform independent. Types of Java variables have the same size on all platforms so that a variable of type integer of the same size no matter where the Java program is compiled. Once the file has been created. Class using the Java compiler on any platform, then the file. Class can be run on any platform. So "wherever made, can be run anywhere." The slogan is usually summarized as Write Once, Run Anywhere (Wora).Java Multithreading including language. Thread is to declare computer programs to do more than one task at a time the same. Java provides a class for writing multithreaded programs, the program has more than one thread of execution at the same time allowing the program to handle multiple tasks concurrently.
Java programs perform garbage collection which means the program does not need to remove themselves the objects that are not used anymore. These facilities reduce the burden of memory management by the programmer and reduce or eliminate the largest source of error contained in the language that allows dynamic allocation.Java has exception-handling mechanisms are powerful. Exception-handling provides a way to separate the error handling with the normal code so that leads to structure the program code that is cleaner and makes the application more rigid. When serious errors are found, the Java program to create an exception. Exception can be captured and managed the program without the risk of making the system to be down.
Java programs support native methods are functions written in another language, usually C / C + +. Support native method allows programmers to write functions that can be executed faster than the equivalent functionality in java. Native methods are dynamically will be a link to a java program, which is associated with the current program running.
Besides the advantages of using the Java programming language include memory on the Java garbage collector automatically equipped with a working memory mendealokasi unnecessary. No more attempts are made programmers to do the dispose (). We are no longer burdened with the memory corruption affairs.Java implement the actual array, eliminating the need pointer arithmetic of dangerous and easily be wrong. Eliminating multiple inheritance (multiple inheritance) is replaced interface facilities. And easy to run in different platforms.Grafical User Interface (GUI) is one of the Java capabilities in support of management and graphical interface. Graphical display will be shown to connect with the program and data storage. The basic elements of Java for a graphical display penciptan are two packages namely AWT and Swing. Abstract Windowing Toolkit (AWT), also called "Another Windowing Toolkit", is a general purpose library and multiplatform windowing as well as providing a number of classes to create a GUI in Java. With AWT, can make a window, drawing, image manipulation, and components like Button, Scrollbar, checkbox, textfield, and pull-down menu.
Use of AWT components are marked with the instruction: import java.awt .*; Swing is an improvement in AWT weakness. Many Swing classes provide an alternative to the AWT components. Examples Swing JButton class provides more functionality than the Button class. In addition, Swing components are generally begins with the letter "J", such as JButton, JTextField, JFrame, JLabel, JTextArea, JPanel, and so forth.Swing Technology use and expand the ideas of AWT. Meanwhile, the use of Swing components are marked with the instruction: import javax.swing .*;
Some differences in AWT and Swing, AWT is a component Heavyweight (weight class), while the lightweight Swing (lightweight). Swing has more components.Facilities Swing Look and Feel: Metal, Windows, Motif. Swing components based on model-view, which is a way of development components with the separation of storage and handling of data from a visual representation of data.
The Java programming language is one of the common programming languages used to develop database applications created using MySQL.