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What is java programming language?
What is actually Java Programming Language? Okay, the first one can say that this is a good Object-Oriented Programming Language, where other Programming Languages are best removed and put together with some Supplement, for example, security models that are important for Internet applications. Java has a broad standard library of classes, which makes programming very much Effective.
Support for Network Communications, Windows Management, File Management, audio, and video, security, data access, etc.
When the source code is compiled in Java language, a Java byte code is generated. Byte code is a low-level language, which includes machine instructions for Java Virtual Machine. Byte code makes Java free from any platform.
The Java Virtual Machine is an intangible Computer on which the byte code can be executed. Java virtual machine becomes a mid-level between byte code and any operating The system, therefore, is seen by the byte code perspective, it always runs on its computer.
Java virtual machine has been implemented as software Operating System Windows NT, Windows 95, Solaris, and macOS For faster performance, Java Virtual Machine will be created in silicon.
This image shows that the source code written by programmers and byte codes are Similar to all platforms. The source code can be compiled on different platforms such as Pentium, PowerPC, Spark and so on, but the result is always the same Java byte code.
Byte code can be executed on various Java virtual machines. the difference between Java and other programming languages is that the source code should not be rewritten. For various Operating Systems, neither for new processors.
An applet is a Java byte code that can be distributed and used through the World Wide Web. In a web page
What we are looking at here is a server, world wide web and a client. There on the server machine is a web server that is capable of sending HTML-pages and adjacent files. The customer is machine A web browser When a user clicks on a link to a page with reference to an applet, then the browser will
Download both Pages and Applets.
Then it will present the page to the user and start Applet To run, the applet requires a Java virtual machine. The most modern web- The Java Virtual Machine has been built in the browser, and since almost everybody is surfing the net A browser, they also have a Java virtual machine.
Since the user has downloaded the applet in the web browser on his computer, so he has New possibilities for interactivity, directly on the customer Compare it to using the old CGI-Technology, where there will be demand for intensive network traffic between interactivity Client and server
There is also the possibility of having more than one Java applet for the web page. This java applet can communicate with each other.
Java virtual machine has been implemented as software Operating System Windows NT, Windows 95, Solaris, and macOS For faster performance, Java Virtual Machine will be created in silicon.
Java language is platform-independent
This image shows that the source code written by programmers and byte codes are Similar to all platforms. The source code can be compiled on different platforms such as Pentium, PowerPC, Spark and so on, but the result is always the same Java byte code.
Byte code can be executed on various Java virtual machines. the difference between Java and other programming languages is that the source code should not be rewritten. For various Operating Systems, neither for new processors.
Java applets can be distributed by www
An applet is a Java byte code that can be distributed and used through the World Wide Web. In a web page
What we are looking at here is a server, world wide web and a client. There on the server machine is a web server that is capable of sending HTML-pages and adjacent files. The customer is machine A web browser When a user clicks on a link to a page with reference to an applet, then the browser will
Download both Pages and Applets.
Then it will present the page to the user and start Applet To run, the applet requires a Java virtual machine. The most modern web- The Java Virtual Machine has been built in the browser, and since almost everybody is surfing the net A browser, they also have a Java virtual machine.
Since the user has downloaded the applet in the web browser on his computer, so he has New possibilities for interactivity, directly on the customer Compare it to using the old CGI-Technology, where there will be demand for intensive network traffic between interactivity Client and server
There is also the possibility of having more than one Java applet for the web page. This java applet can communicate with each other.
Applets can also read the parameters from the HTML page; That's the case The possibility of affecting some settings of applets using different HTML pages One The example HTML page is an applet giving different layouts for text and text Layout settings can be both parameters in HTML page red by applet To keep the high level of protection, to prevent the spread of the virus, Netscape and
Microsoft strongly chose what an applet is allowed to do.
This can not be for, For example, communicate with a different computer than it was Downloaded. In addition, this client cannot read or write on any file in the machine.
Java is an elegant Object-oriented language with a simple creation. Java producer James Gosling at the SUN selected and combined the best parts of many different languages. Java's syntax is nearly identical in C ++, but Java is simple and More object-oriented
Java has support for multi-threaded applications so many tasks can run parallel. A thread can manipulate user interfaces, at the same time as another thread is scanning Trap
Java has automatic memory management, which reduces complexity Programming Memory is not directly accessible, causing fewer viruses and other Insects in programs.
Java's security model is usually called "sand-box-model" since the Java program Get only a limited portion of the computer to execute.
With the help of a security manager, and self-described security policy, Java is Permitted to be done at an application level, are limited. With a security manager, you can set up Whether Java is allowed to read or write a file, the computer allows it to be contacted or if It is allowed to call the C-program.
No direct access to the computer's memory is possible from the pure Java program, which This means that the risk of deleting or altering applets from your hard disk is significantly reduced.
Microsoft strongly chose what an applet is allowed to do.
This can not be for, For example, communicate with a different computer than it was Downloaded. In addition, this client cannot read or write on any file in the machine.
Example of java applet
Java is an elegant Object-oriented language with a simple creation. Java producer James Gosling at the SUN selected and combined the best parts of many different languages. Java's syntax is nearly identical in C ++, but Java is simple and More object-oriented
Java has support for multi-threaded applications so many tasks can run parallel. A thread can manipulate user interfaces, at the same time as another thread is scanning Trap
Java has automatic memory management, which reduces complexity Programming Memory is not directly accessible, causing fewer viruses and other Insects in programs.
Java Language is secure
Java's security model is usually called "sand-box-model" since the Java program Get only a limited portion of the computer to execute.
With the help of a security manager, and self-described security policy, Java is Permitted to be done at an application level, are limited. With a security manager, you can set up Whether Java is allowed to read or write a file, the computer allows it to be contacted or if It is allowed to call the C-program.
No direct access to the computer's memory is possible from the pure Java program, which This means that the risk of deleting or altering applets from your hard disk is significantly reduced.
Apart from this, the code is controlled not only on the compilation but also for loading Performance. Java Virtual Machine does not have permission to run any invalid Java code.
Java company Sun, Javasoft, is currently developing four different versions of Java. Language is always the same, but the difference is the size of that class library Were included. Embedded Java is a minimal part of Java for use in small platforms,
e.g. smart card Or software has controlled the electrical components in which you want to download the software Change it from a network and dynamically.
Personal Java is intended for products of some types of display, although there is a lack of a keyboard.
Those products can be the fax, copy machine, TV set, video or other home-electronics Which dynamically wants to change the software.
Standard Java is the original and most expanded Java environment, which has the capability Be one of the big developing environments in the next decade.
Enterprise Java is to be used in more professional development applications. More attachments for commercial models than security models and standard Java.
There is a comprehensive standard library for Java. Developers can trust this Every standard Java platform. In addition to this library, there are many other classes Sun & Other Equipment Supplier
Standard Library includes a package for managing user interfaces, AWT or abstract windows Toolkit This is the biggest, and the standard Java package is the most important. It contains Classes that allow you to manipulate windows, dialogs, graphics, buttons, and so on.
A program Due to this fact, something different will appear on various platforms written with AWT Java virtual machine uses components of related operating system to display AWT-component on-screen
Another frequently used package is an applet-package that is used to create applets. Net-package is used for network communication management, which also supports TCP / IP Communications.
The I / O-package is used to read and write files, including files accessed on the Internet. Support for access to the ODBC-database with the help of SQL in the SQL-package Standard language
Security package supports data-encryption. Support for digital signatures, and Public Key Encryption
The RMI package, which is for removing the request, supports the building Applications distributed on one network. Being able to communicate with a program with RMI Programs that run on other computers. In this way, you can divide jobs among many people computer.
Class library accelerates program development because the programmer is enabled By using what is already written and whatever is working, do not do it by yourself. Another advantage is that only small programs need to be moved over the net since The class library already exists on the Java platform.
The user interface event is controlled in Java. When a user pushes a key or moves the mouse, The operating system generates events. These events are caught by the Java environment and Converted to Java Event. There are programs for different sections and different parts The Java program can choose which ones to listen to.
Events do not always need to come from the operating system. They can be straight Generated by java program In this way, the programmer can gain increased control and Events can be simulated.
Java Beans is a standard for software components in Java. The programmer can create Since faster applications, he can already collect the pieces in large pieces. The objective of Java Beans is to provide bean-components for purchase from various Suppliers so that a programmer does not need to program everything from scratch.
JavaBean is a software component that can be handled by various software graphs equipment.
The idea is that a programmer can combine the Java Beans graphically, without which Type the code. Tools automatically generate codes.
Java Beans can be compared with Microsoft's Industrial Standard ActiveX Software component ActiveX is an old and reliable technique in this context. On OLE and DCOM This means that there is already a lot of ActiveX-component present. Unlike Active X, the Java Beans component is fully written in Java, and therefore Platform is free.
Java is an open system, which means that Java can cooperate with other types of systems. There are also some attachments for other object models and languages on the network.
For a Java program to be integrated into another network with another Java program, RMI (Remote method invocation) is preferred, as it contains Java-specific optimization. Java Bean architecture can also be used at a higher level.
If instead of writing in the program, say, C ++ or Smalltalk, CORBA can be used, supported To integrate the system by java.
Java has inherent support for communication with the ODBC Database. Apple and IBM also have links to OpenDoc.
If ActiveX is required to use, then there is a bridge, so a Java Bean can be easily converted In an ActiveX component.
Java in four versions
Java company Sun, Javasoft, is currently developing four different versions of Java. Language is always the same, but the difference is the size of that class library Were included. Embedded Java is a minimal part of Java for use in small platforms,
e.g. smart card Or software has controlled the electrical components in which you want to download the software Change it from a network and dynamically.
Personal Java is intended for products of some types of display, although there is a lack of a keyboard.
Those products can be the fax, copy machine, TV set, video or other home-electronics Which dynamically wants to change the software.
Standard Java is the original and most expanded Java environment, which has the capability Be one of the big developing environments in the next decade.
Enterprise Java is to be used in more professional development applications. More attachments for commercial models than security models and standard Java.
Java standard library
There is a comprehensive standard library for Java. Developers can trust this Every standard Java platform. In addition to this library, there are many other classes Sun & Other Equipment Supplier
Standard Library includes a package for managing user interfaces, AWT or abstract windows Toolkit This is the biggest, and the standard Java package is the most important. It contains Classes that allow you to manipulate windows, dialogs, graphics, buttons, and so on.
A program Due to this fact, something different will appear on various platforms written with AWT Java virtual machine uses components of related operating system to display AWT-component on-screen
Another frequently used package is an applet-package that is used to create applets. Net-package is used for network communication management, which also supports TCP / IP Communications.
The I / O-package is used to read and write files, including files accessed on the Internet. Support for access to the ODBC-database with the help of SQL in the SQL-package Standard language
Security package supports data-encryption. Support for digital signatures, and Public Key Encryption
The RMI package, which is for removing the request, supports the building Applications distributed on one network. Being able to communicate with a program with RMI Programs that run on other computers. In this way, you can divide jobs among many people computer.
Class library accelerates program development because the programmer is enabled By using what is already written and whatever is working, do not do it by yourself. Another advantage is that only small programs need to be moved over the net since The class library already exists on the Java platform.
Event handling in java
The user interface event is controlled in Java. When a user pushes a key or moves the mouse, The operating system generates events. These events are caught by the Java environment and Converted to Java Event. There are programs for different sections and different parts The Java program can choose which ones to listen to.
Events do not always need to come from the operating system. They can be straight Generated by java program In this way, the programmer can gain increased control and Events can be simulated.
Java beans
Java Beans is a standard for software components in Java. The programmer can create Since faster applications, he can already collect the pieces in large pieces. The objective of Java Beans is to provide bean-components for purchase from various Suppliers so that a programmer does not need to program everything from scratch.
JavaBean is a software component that can be handled by various software graphs equipment.
The idea is that a programmer can combine the Java Beans graphically, without which Type the code. Tools automatically generate codes.
Java Beans can be compared with Microsoft's Industrial Standard ActiveX Software component ActiveX is an old and reliable technique in this context. On OLE and DCOM This means that there is already a lot of ActiveX-component present. Unlike Active X, the Java Beans component is fully written in Java, and therefore Platform is free.
Different types of integration
Java is an open system, which means that Java can cooperate with other types of systems. There are also some attachments for other object models and languages on the network.
For a Java program to be integrated into another network with another Java program, RMI (Remote method invocation) is preferred, as it contains Java-specific optimization. Java Bean architecture can also be used at a higher level.
If instead of writing in the program, say, C ++ or Smalltalk, CORBA can be used, supported To integrate the system by java.
Java has inherent support for communication with the ODBC Database. Apple and IBM also have links to OpenDoc.
If ActiveX is required to use, then there is a bridge, so a Java Bean can be easily converted In an ActiveX component.
There is also the support of calling the C ++ method directly from within the Java program.
Java Commerce API is an extension of Java's class library. This will be in detail Support for business on the Net. It would be easy to accept payment for the program and the data Use, and an open platform will be available for bank and finance applications.
In Java, Commerce APIs will have ways to control the encryption and authorization of messages.
There will be partially prefabricated programs for inclusion in the Java Communications API Handling sales and high-level components for finance applications.
Java Telephony API is a package for computer and telephone integration. with this, The API is possible to control a telephone card in this computer. There are plenty of possibilities for Control a telephone, simple or cellular through the Java program.
An example is to get a graphical interface for your telephone, in which you are included Want to order Alarm calls, call waiting and other services can be shown academically Ordering will be easy. Also, new opportunities will open for more Advanced Tasks.
How does Java compare to other technologies on the Internet?
Java shows great parallels with C ++. Java platform is free that is not C ++ but it is C ++ is more mature, and performs better.
CGI-TECH is used to make long forms and active surfaces HTML-pages have Although this technique is free on customer part, Performance is so low due to constant network communication, that is only a small part Java's functionality is achieved.
ActiveX should not be directly compared with Java because it is an architecture for software Organ Compared to Java beans, which is equal to ActiveX, the difference is ActiveX is fast but the platform is not free.
Shockwave is a family of plug-ins from Macromedia. It has a high level of interactivity but its client does not require the installation of Java language.
In summary, consider the possibility of expanding the platform's independence, security, one While running it, the program with new parts, and very strong industrial support, can be one It is said that Java is a good option for many applications.
Java commerce API
Java Commerce API is an extension of Java's class library. This will be in detail Support for business on the Net. It would be easy to accept payment for the program and the data Use, and an open platform will be available for bank and finance applications.
In Java, Commerce APIs will have ways to control the encryption and authorization of messages.
There will be partially prefabricated programs for inclusion in the Java Communications API Handling sales and high-level components for finance applications.
Java telephony API
Java Telephony API is a package for computer and telephone integration. with this, The API is possible to control a telephone card in this computer. There are plenty of possibilities for Control a telephone, simple or cellular through the Java program.
An example is to get a graphical interface for your telephone, in which you are included Want to order Alarm calls, call waiting and other services can be shown academically Ordering will be easy. Also, new opportunities will open for more Advanced Tasks.
Alternative to java
How does Java compare to other technologies on the Internet?
Java shows great parallels with C ++. Java platform is free that is not C ++ but it is C ++ is more mature, and performs better.
CGI-TECH is used to make long forms and active surfaces HTML-pages have Although this technique is free on customer part, Performance is so low due to constant network communication, that is only a small part Java's functionality is achieved.
ActiveX should not be directly compared with Java because it is an architecture for software Organ Compared to Java beans, which is equal to ActiveX, the difference is ActiveX is fast but the platform is not free.
Shockwave is a family of plug-ins from Macromedia. It has a high level of interactivity but its client does not require the installation of Java language.
In summary, consider the possibility of expanding the platform's independence, security, one While running it, the program with new parts, and very strong industrial support, can be one It is said that Java is a good option for many applications.
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