Thursday, May 21, 2009
Wednesday, February 25, 2009
Also some more importent
* Custom Networking — An introduction to the Java platform's powerful networking features.
* The Extension Mechanism — How to make custom APIs available to all applications running on the Java platform.
* Full-Screen Exclusive Mode API — How to write applications that more fully utilize the user's graphics hardware.
* Generics — An enhancement to the type system that supports operations on objects of various types while providing compile-time type safety. Note that this lesson is for advanced users. The Java Language trail contains a Generics lesson that is suitable for beginners.
* Internationalization — An introduction to designing software so that it can be easily be adapted (localized) to various languages and regions.
* JavaBeans — The Java platform's component technology.
* JDBC Database Access — Introduces an API for connectivity between the Java applications and a wide range of databases and a data sources.
* JMX— Java Management Extensions provides a standard way of managing resources such as applications, devices, and services.
* JNDI— Java Naming and Directory Interface enables accessing the Naming and Directory Service such as DNS and LDAP.
* RMI — The Remote Method Invocation API allows an object to invoke methods of an object running on another Java Virtual Machine.
* Reflection — An API that represents ("reflects") the classes, interfaces, and objects in the current Java Virtual Machine.
* Security — Java platform features that help protect applications from malicious software.
* Sound — An API for playing sound data from applications.
* 2D Graphics — How to display and print 2D graphics in applications.
* The Extension Mechanism — How to make custom APIs available to all applications running on the Java platform.
* Full-Screen Exclusive Mode API — How to write applications that more fully utilize the user's graphics hardware.
* Generics — An enhancement to the type system that supports operations on objects of various types while providing compile-time type safety. Note that this lesson is for advanced users. The Java Language trail contains a Generics lesson that is suitable for beginners.
* Internationalization — An introduction to designing software so that it can be easily be adapted (localized) to various languages and regions.
* JavaBeans — The Java platform's component technology.
* JDBC Database Access — Introduces an API for connectivity between the Java applications and a wide range of databases and a data sources.
* JMX— Java Management Extensions provides a standard way of managing resources such as applications, devices, and services.
* JNDI— Java Naming and Directory Interface enables accessing the Naming and Directory Service such as DNS and LDAP.
* RMI — The Remote Method Invocation API allows an object to invoke methods of an object running on another Java Virtual Machine.
* Reflection — An API that represents ("reflects") the classes, interfaces, and objects in the current Java Virtual Machine.
* Security — Java platform features that help protect applications from malicious software.
* Sound — An API for playing sound data from applications.
* 2D Graphics — How to display and print 2D graphics in applications.
Essential Classes
Essential Classes
This trail discusses classes from the Java platform that are essential to most programmers.
Exceptions explains the exception mechanism and how it is used to handle errors and other exceptional conditions. This lesson describes what an exception is, how to throw and catch exceptions, what to do with an exception once it has been caught, and how to use the exception class hierarchy.
Basic I/O covers the Java platform classes used for basic input and output. It focuses primarily on I/O Streams, a powerful concept that greatly simplifies I/O operations. The lesson also looks at Serialization, which lets a program write whole objects out to streams and read them back again. Then the lesson looks at some file system operations, including random access files. Finally, it touchs briefly on the advanced features of the New I/O API.
Concurrency explains how to write applications that perform multiple tasks simultaneously. The Java platform is designed from the ground up to support concurrent programming, with basic concurrency support in the Java programming language and the Java class libraries. Since version 5.0, the Java platform has also included high-level concurrency APIs. This lesson introduces the platform's basic concurrency support and summarizes some of the high-level APIs in the java.util.concurrent packages.
Regular Expressions are a way to describe a set of strings based on common characteristics shared by each string in the set. They can be used to search, edit, or manipulate text and data. Regular expressions vary in complexity, but once you understand the basics of how they're constructed, you'll be able to decipher (or create) any regular expression. This lesson teaches the regular expression syntax supported by the java.util.regex API, and presents several working examples to illustrate how the various objects interact.
The Platform Environment is defined by the underlying operating system, the Java virtual machine, the class libraries, and various configuration data supplied when the application is launched. This lesson describes some of the APIs an application uses to examine and configure its platform environment.
Lesson: Object-Oriented Programming Concepts
Lesson: Object-Oriented Programming Concepts
If you've never used an object-oriented programming language before, you'll need to learn a few basic concepts before you can begin writing any code. This lesson will introduce you to objects, classes, inheritance, interfaces, and packages. Each discussion focuses on how these concepts relate to the real world, while simultaneously providing an introduction to the syntax of the Java programming language.
What Is an Object?
An object is a software bundle of related state and behavior. Software objects are often used to model the real-world objects that you find in everyday life. This lesson explains how state and behavior are represented within an object, introduces the concept of data encapsulation, and explains the benefits of designing your software in this manner.
What Is a Class?
A class is a blueprint or prototype from which objects are created. This section defines a class that models the state and behavior of a real-world object. It intentionally focuses on the basics, showing how even a simple class can cleanly model state and behavior.
What Is Inheritance?
Inheritance provides a powerful and natural mechanism for organizing and structuring your software. This section explains how classes inherit state and behavior from their superclasses, and explains how to derive one class from another using the simple syntax provided by the Java programming language.
What Is an Interface?
An interface is a contract between a class and the outside world. When a class implements an interface, it promises to provide the behavior published by that interface. This section defines a simple interface and explains the necessary changes for any class that implements it.
What Is a Package?
A package is a namespace for organizing classes and interfaces in a logical manner. Placing your code into packages makes large software projects easier to manage. This section explains why this is useful, and introduces you to the Application Programming Interface (API) provided by the Java platform.
Questions and Exercises: Object-Oriented Programming Concepts
Use the questions and exercises presented in this section to test your understanding of objects, classes, inheritance, interfaces, and packages.
If you've never used an object-oriented programming language before, you'll need to learn a few basic concepts before you can begin writing any code. This lesson will introduce you to objects, classes, inheritance, interfaces, and packages. Each discussion focuses on how these concepts relate to the real world, while simultaneously providing an introduction to the syntax of the Java programming language.
What Is an Object?
An object is a software bundle of related state and behavior. Software objects are often used to model the real-world objects that you find in everyday life. This lesson explains how state and behavior are represented within an object, introduces the concept of data encapsulation, and explains the benefits of designing your software in this manner.
What Is a Class?
A class is a blueprint or prototype from which objects are created. This section defines a class that models the state and behavior of a real-world object. It intentionally focuses on the basics, showing how even a simple class can cleanly model state and behavior.
What Is Inheritance?
Inheritance provides a powerful and natural mechanism for organizing and structuring your software. This section explains how classes inherit state and behavior from their superclasses, and explains how to derive one class from another using the simple syntax provided by the Java programming language.
What Is an Interface?
An interface is a contract between a class and the outside world. When a class implements an interface, it promises to provide the behavior published by that interface. This section defines a simple interface and explains the necessary changes for any class that implements it.
What Is a Package?
A package is a namespace for organizing classes and interfaces in a logical manner. Placing your code into packages makes large software projects easier to manage. This section explains why this is useful, and introduces you to the Application Programming Interface (API) provided by the Java platform.
Questions and Exercises: Object-Oriented Programming Concepts
Use the questions and exercises presented in this section to test your understanding of objects, classes, inheritance, interfaces, and packages.
Wednesday, October 8, 2008
java is cool
The Java Programming Language
The Java programming language is a high-level language that can be characterized by all of the following buzzwords:
Simple
Architecture neutral
Object oriented
Portable
Distributed
High performance
Multithreaded
Robust
Dynamic
Secure
The Java programming language is a high-level language that can be characterized by all of the following buzzwords:
Simple
Architecture neutral
Object oriented
Portable
Distributed
High performance
Multithreaded
Robust
Dynamic
Secure
Each of the preceding buzzwords is explained in The Java Language Environment , a white paper written by James Gosling and Henry McGilton.
In the Java programming language, all source code is first written in plain text files ending with the .java extension. Those source files are then compiled into .class files by the javac compiler. A .class file does not contain code that is native to your processor; it instead contains bytecodes — the machine language of the Java Virtual Machine1 (Java VM). The java launcher tool then runs your application with an instance of the Java Virtual Machine.
An overview of the software development process.
Because the Java VM is available on many different operating systems, the same .class files are capable of running on Microsoft Windows, the Solaris TM Operating System (Solaris OS), Linux, or Mac OS. Some virtual machines, such as the Java HotSpot virtual machine, perform additional steps at runtime to give your application a performance boost. This include various tasks such as finding performance bottlenecks and recompiling (to native code) frequently used sections of code.
Through the Java VM, the same application is capable of running on multiple platforms.
The Java Platform
A platform is the hardware or software environment in which a program runs. We've already mentioned some of the most popular platforms like Microsoft Windows, Linux, Solaris OS, and Mac OS. Most platforms can be described as a combination of the operating system and underlying hardware. The Java platform differs from most other platforms in that it's a software-only platform that runs on top of other hardware-based platforms.
The Java platform has two components:
In the Java programming language, all source code is first written in plain text files ending with the .java extension. Those source files are then compiled into .class files by the javac compiler. A .class file does not contain code that is native to your processor; it instead contains bytecodes — the machine language of the Java Virtual Machine1 (Java VM). The java launcher tool then runs your application with an instance of the Java Virtual Machine.
An overview of the software development process.
Because the Java VM is available on many different operating systems, the same .class files are capable of running on Microsoft Windows, the Solaris TM Operating System (Solaris OS), Linux, or Mac OS. Some virtual machines, such as the Java HotSpot virtual machine, perform additional steps at runtime to give your application a performance boost. This include various tasks such as finding performance bottlenecks and recompiling (to native code) frequently used sections of code.
Through the Java VM, the same application is capable of running on multiple platforms.
The Java Platform
A platform is the hardware or software environment in which a program runs. We've already mentioned some of the most popular platforms like Microsoft Windows, Linux, Solaris OS, and Mac OS. Most platforms can be described as a combination of the operating system and underlying hardware. The Java platform differs from most other platforms in that it's a software-only platform that runs on top of other hardware-based platforms.
The Java platform has two components:
The Java Virtual Machine
The Java Application Programming Interface (API) You've already been introduced to the Java Virtual Machine; it's the base for the Java platform and is ported onto various hardware-based platforms.
The API is a large collection of ready-made software components that provide many useful capabilities. It is grouped into libraries of related classes and interfaces; these libraries are known as packages. The next section, What Can Java Technology Do? highlights some of the functionality provided by the API.
The API and Java Virtual Machine insulate the program from the underlying hardware.As a platform-independent environment, the Java platform can be a bit slower than native code. However, advances in compiler and virtual machine technologies are bringing performance close to that of native code without threatening portability.
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