One reason you may find your computer freezing and slowing down is corrupt or error filled registry entries and an effortless and fast way to get a slow computer fix is running a good system and registry scanning program on your PC. This will not just search for registry errors but for malware and windows errors as well.

A slow PC can drive you crazy and can result in considerable problems in getting anything done. If your computer keeps running slow or freezing for no apparent reason there is a good chance there are errors in the windows registry.

Over time your systems registry gets corrupted, causing a PC slow down. In these instances, the best slow computer fix is running a system and registry program. You can download and run this yourself. Even if you have no computer knowledge.

Your registry could be corrupt simply because of installing and uninstalling programs on your system. The PC registry is the windows core and this controls how it runs and how efficiently it runs and the speed it runs at to a large extent.

Things like viruses and adware can also get on your computer and in the windows registry and fill it with unnecessary and redundant files and can even damage it to the point where your entire system becomes inoperable. A system and registry scanner will search for malware and stop it.

Downloading a system and registry scanner can eradicate this particular problem and put your computer back into its original state for a slow computer fix and to make it run faster.

An increasing amount of registry errors left unfixed will eventually result in your computer slowing down, crashing and eventually can cause windows to fail to start at all. Inevitably once registry errors and damage starts to appear it will only get worse, unless you fix it.

This scenario calls for a system and registry cleaner that will detect and identify the invalid registry entries and repair them. That's how a system and registry scanner gets rid of computer problems and make your PC work faster. If your computer is running slow and you need a slow computer fix scan it now and speed it up again.

Here is the answer for a Slow Computer fix this will make your PC faster, just click here now Article Source: http://EzineArticles.com/?expert=James_Randell

• 0 komentar »

If you are determined to make an income with AdSense, you will find that you stand a great chance of reaching the goals you set. However, as with any business opportunity, you may have your ups and downs. This is the reason that it is so important to take some time out of your busy schedule to learn what you can do to make it easier for you. The following are some tips on how to earn money with AdSense that every beginner will find useful:

First and foremost, to earn money with AdSense, you have to choose a good web hosting company. Free hosting is going to probably subject your site to banners and other pop up ads that will just result in getting your site rejected by Google.

When choosing the subject for your website, do not choose a topic because it is popular. Instead, choose a topic that you are knowledgeable about, as this will help you to be able to write more content about it and write it quickly.

You must also be sure your topic is not too broad, but not too narrow, as well. For example, if you are going to base it on sewing, you could base it on sewing children's clothing, but sewing children's size 2T clothing would be too narrow.

While a lot of people think they can just create a site and make money, there is more to it than this. You must constantly be working to increase how much traffic you get to the site. This means you should take time to study the different ways you can market your website online.

Many people who apply with Google for an account get frustrated with the length of time it takes to get a response. During this time, they forget about their site and are surprised when their site is rejected. This is a big mistake, as Google wants to see continuous traffic to your site and, while you wait for a response, you should still be updating your site with new content and trying to drive more traffic. If you don't, you may just find that this particular site is not going to earn money with AdSense.

Learn The Secret To Adsense Profits at www.AdsenseRepublic.info! Article Source: http://EzineArticles.com/?expert=Jordan_Michael

• 0 komentar »

LED, also known as Light Emitting Diode, is basically used as indicator lamp in various electronic devices like computers, clock radios, TV's, DVD players and MP3 players. The usage of LED's has been quite popular in various parts of the world for decades. However, the specialty of today's LED's is to be available at most affordable prices and in a huge assortment of colors providing bright and crystal-clear light. The incandescent light bulb and lamp has been serving the people for their different light purposes for nearly 100 years. According to experts, the LED work light lamps and bulbs have now become an ideal for at-home use and for professionals and they will soon replace a wide variety of incandescent light bulb and lamp.

What is LED Light Bulb All About?

The working system of LED light bulb is just similar to traditional light bulb. However, the main feature of LED is that it is very easy to fit it directly into an electrical circuit. LED's are specially known for their long lasting life because the absence of filament allows them to spread the light without burning out. The filament generally generates heat, so in LED's bulbs and lamps don't get hot because they don't have filament. Apart from it, the LED work light bulbs use comparatively less electric power than traditional light bulbs.

Market is flooded with a wide range of LEDs which come in a huge variety of colors. Some commonly used colors of LED's are green, yellow and red. However, most people like to buy LED that is available in while color. As a matter of fact, it is presently impossible for LED's bulbs and lamps providers to create pure white color. It has been generally seen that these days most LED flash lights or don't come in pure white color, but their color are whitish-blue instead of pure white.

Benefits of LED light bulbs and lamps:

The great efficiency of LEDs bulbs and lamps make them a perfect alternative for camping, workshop, roadside assistance, electricians, plumbers, motorcycle lights, automotive repairs, garage, during power outages and more. The LED work Light lamps are bulbs can be mass produced and are available at rock bottom prices.

Lou Drennan has been credited with the achievement of writing different types of content on a wide range of rotary and oscillating power tools. The author has experience of providing information on a wide variety of miniature tools, rotary tools and miniature precision tools. for more information visit LED work light. Article Source: http://EzineArticles.com/?expert=Lou_Drennan

• 0 komentar »

DVI-D to VGA converter is used when you need to connect a VGA monitor or a VGA projector to a computer with a DVI-D Single link video card. This converter has been specifically designed to connect computers with DVI-D single link graphics card to analog VGA monitors. It supports a wide variety of VGA resolutions (1900 x1200, 1600 x 1200, 1280x1024 and lower) and is HDCP compliant. The converter is best used when one does not want to replace costly video monitors; thereby extending the life of the present equipment. The default video resolution is 1280 x 1024 for these DVI to VGA converter units.

The Video Converter is a hardware device which allows converting a video signal into a specific format which is compatible with a specific type of display. The different types of converters available are DVI-D to VGA; VGA to DVI-D; Multi Video digital converter; USB to DVI and VGA; DVI to HDMI converter; RGB YPbPr to HDMI Converter; VGA to HDMI Converter.

VGA to DVI-D converter enables you to convert analog VGA signal to DVI-D (digital graphic) signal so that devices with digital DVI-D Single link display can be connected to your computer with analog VGA output. The multi video digital converter is a bi-directional converter which has S-Video (4 Pin miniDin) / Composite Video (RCA type) / VGA inputs and allows you to connect a TV to PC or PC to TV with VGA/ S-Video (4 Pin miniDin) / Composite Video (RCA type) outputs.

The DVI-D to VGA video converter is a true digital to analog video converter. This converter draws it power from the DVI port on the PC and external Power supply is not required in most cases. It supports simple plug and play functionality.

I am associated with this technology DVI-D to VGA, VGA to DVI-D, DVI to VGA converter from last 12 years. I always try to provide quality information for the users. Article Source: http://EzineArticles.com/?expert=Peter_Disuja

• 0 komentar »

How Wireless Router Reviews Can Help You

If you have been using the built in wireless network in your computer's internet sharing device, you must be quite satisfied with its performance, though there is a setback. The computer where the modem is linked and connected should be turned on prior to allowing other computers obtain internet access. Although, this is okay for a while, it can be a problem later on. Learning about wireless router reviews will let you understand why you should upgrade to a router.

A wireless network router is a low-powered and small computer device, which has the sole purpose of granting you internet access with the use of a wireless network. Once a router is installed and set up, you can let other computers be connected to the World Wide Web through your network any moment you desire. Because this is the chief and the only function of wireless routers, they normally don't require any configuration to run, permitting you to go online and surf the net anytime with ease.

If you have already decided to get a router, wireless router reviews can help you a lot in determining what features you should look for in this device. When searching for a wireless router, you should consider the same factors that you closely look at when you buy other wireless equipment.

Check the package's speed, range and limitations. It's vital to note that speed is very important with a network router just like it is with other connection and communication devices. Because the router you will buy might need to provide internet access to several computers at the same time, it will need adequate speed to share between each computer. Reading reviews will let you recognize what's the easiest and most efficient router on the market today. Although you don't need to go over the top and purchase very expensive routers, you should critically check the features of less costly brands. As is typical with other devices, the most vital thing to carry out is to look for as many reviews as possible before buying one.

The good thing about routers is that they are specifically designed to work almost effortlessly. In most instances, it is just a matter of connecting or plugging the router in your power supply and then linking it to your cable, may it be DSL or other modem types. After which, you are ready to go online using your wireless internet connection.

If you are utilizing an ISP for your internet connection, you should note that it makes use of special software to verify who you are before access is granted. This is known as Point-to-Point Protocol over Ethernet (PPPoE). You are required to undergo this short procedure to utilize a PPPoE connection with a wireless network router.

Reading wireless router reviews is without doubt a surefire way of learning about any problems and setbacks that may take place because of these devices. A router most of the time solves more internet connection problems than they cause, though there are still some situations and functions that may require you to use a direct internet connection.

By: Derrick Richardson

Article Directory: http://www.articledashboard.com

• 0 komentar »

Over the past decade, as Internet security has become a chief concern of IT professionals, one of the most common questions administrators and users ask is, "Which is more secure, SFTP or FTPS?"

In short, both protocols offer a high level of security and both are suitable for meeting the requirements imposed on most organizations by internal policies and state and federal regulations, including the Health Insurance Portability And Accountability Act (HIPAA), the Sarbanes-Oxley Act (SOX), the Gramm-Leach-Bliley Act (GLBA), etc.

For those looking for a deeper understanding of the differences between these two file transfer protocols, this article reviews what we mean by "security" and then examines how these protocols work and what mechanisms they use to ensure the security of a transmission.

When evaluating the security of a particular method of moving data between systems, most users are concerned with meeting three conditions:

1. Confidentiality -- Ensuring that nobody but the intended recipient can see the data being sent.
2. Integrity -- Ensuring that the data cannot be modified by an unauthorized party before reaching the intended recipient.
3. Authenticity -- Ensuring that both the sender and recipient are who they say they are.

Now that we know what kind of security we need, we can next examine how the FTPS and SFTP protocols work and how they achieve these security goals.

FTPS is a combination of two technologies: FTP and SSL. FTP is a network file transfer protocol that was first described in RFC 959 in 1980 and has gone through numerous changes and additions since that time. By itself, FTP offers no meaningful security. Connections are password-protected, but all data (including passwords) is sent in plain text over the network. An FTP connection can be secured by using the SSL/TLS protocol, as described in RFC 2228. This combination of using FTP with SSL/TLS has come to be known as FTPS, and most client and servers support it without requiring significant expertise on behalf of the user.

SFTP is a totally different protocol from FTP, although it is used much the same way. SFTP was first described in RFC 4253. Where FTPS uses SSL to secure the connection, SFTP uses the SSH protocol.

SSL and SSH, the security protocols used by FTPS and SFTP, respectively, both utilize essentially the same techniques to secure a connection. The primary difference is in how they handle authentication (#3 in our list of security conditions). SSL uses X.509 certificates where SSH instead uses SSH keys.

This is where many consider SSL to have a slight edge over SSH. An X.509 certificate (more commonly known as an SSL certificate) is a package that contains a key (like the keys used by SSH) but also includes additional information about the owner of the certificate. A certificate is typically issued by a Certificate Authority (also known as a CA), which is some trusted source that has taken steps to verify the authenticity of the company or person to whom they have issued the certificate.

SSH requires that when you accept a key from a trading partner you have your own method of verifying the authenticity of the key, where SSL allows you to delegate that job to the Certificate Authority that issued the SSL certificate.

This difference in approach to authentication is not necessarily a slam dunk in favor of SSL. For example, who is to say that Certificate Authorities are beyond reproach? It is certainly conceivable that an extremely clever malicious user could find a way to get a CA to issue a certificate to the wrong person. Likewise, the informal techniques often used to verify the authenticity of an SSH key (such as verbally confirming a key's fingerprint by phone) are considered by many to be very reliable. Still, in practice, SSL (and FTPS) is more widely used.

So, as it appears that FTPS and SFTP offer similar levels of security, are there other reasons to choose one over the other? Assuming you have a choice, as many users need to interface with systems where this decision has already been made, there are a few criteria worth considering when choosing between SFTP and FTPS.

FTPS is more popular, so it is more likely that others with whom you wish to exchange data will be able to support it. Advantage: FTPS.

SFTP is easier to administer from a network perspective (firewalls, etc.). SFTP uses only a single TCP port where FTPS requires two. Advantage: SFTP.

FTPS is more flexible and, under the right circumstances, uses less computing resources than SFTP, which can lead to faster performance. Advantage FTPS.

SFTP is a newer protocol with standards that are more clearly defined. For example, SFTP uses a standardized directory listing format, where FTPS does not. Newer additions to FTP offer a standardized way of retrieving a directory listing, although it is not universally supported. It is not uncommon to uncover interoperability issues when connecting FTPs implementations from different vendors, where SFTP encounters such issues less often (although they do happen from time to time). Advantage: SFTP.

As both file transfer protocols have their advantages, it is likely they will continue to co-exist for the foreseeable future. Fortunately, vendors have recognized this trend and many products support both protocols equally well, making the choice between SFTP and FTPS largely academic.

To summarize, SFTP and FTPS offer similar levels of security and both are well-suited to meet the requirements of most organizations, including those bound by state and federal regulations like the Health Insurance Portability And Accountability Act (HIPAA), the Sarbanes-Oxley Act (SOX), the Gramm-Leach-Bliley Act (GLBA), etc.

Errol Siegel is a Product Manager at Serengeti Systems Incorporated, a leading provider of secure, automated file transfer solutions for small to medium-sized businesses. Since 2001, Siegel has lead the team responsible for the Robo-FTP suite, a secure file transfer server and client built from the ground up for automating FTP, FTPS, SFTP, HTTP, and HTTPS file transfers and related tasks such as PGP encryption, ZIP, email (SMTP), and database access (ODBC). Siegel holds a Bachelor's degree in Aerospace Engineering from the University of Michigan. Article Source: http://EzineArticles.com/?expert=Errol_Siegel

• 0 komentar »

The earlier Operating systems from Microsoft were probably not as complex as the latest ones. These have set the registry repair tools to be an integral part of your computer repair tool kit. Registry repair utility applications are essential if you want to prolong the performance and the life of your computer. The complex architecture of your Windows looks out for serious maintenance that is offered by effective registry repair software.

Over time, the software and applications that you install on your system generate a lot of entries in the registry for their usual processes. Not all of these registry entries are necessary yet a number of them need to be removed using a quality registry cleaning tool over time. Even the latest applications are complicated enough generating registry entries are not simple as they used to be a decade back. Combination of all this demands registry repair tools periodically just to make all the useless entries cleared up.

There are a lot of free registry cleaning tools available on the web but they are of no worth to the users as most of them set Trojans and spyware planted into your computer so you should rather make a sensible choice when selecting from a number of available options so that you get protection at the end and not vulnerability.

Registry repair tools not only delete the fake entries from your system's registry but also ensure that your system is safe from vulnerable threats. Registry is the prime target of every virus and spyware that slows down your computer gradually replicating within the registry creating bulk fake entries. Registry tools are perhaps the best way to protect your system from such vulnerabilities increasing the speed and performance of your system on the overall.

The best registry repair tools will keep your computer running at its max performance and will prolong your computer life. To learn more about the best registry cleaners in the market, visit our website at http://www.bestregistryrepairtools.com

• 0 komentar »

The number of reports of cyber fraud have increased over the past few years, and reading through these reports, one would notice that keyloggers are one of the common methods used to commit this crime. One report involved the transfer of funds from one account to another without the knowledge of both the account holder and the bank. The investigation eventually showed that the account holder's computer was infected by a program that recorded each stroke made on the keyboard, and then transmitted that information to the maker of the program. This was how all information of the user, such as the account number and password, was acquired by the hacker.

That type of program is what is called a keylogger. Not all Keyloggers are software though. Some physical devices may be attached between the keyboard and computer with the same exact purpose - secretly monitor computer activities. These were developed a long time ago, but they were not regarded as threats until recently when some people decided to use it to steal personal information, and use that information for committing fraud. This computer program as marketed by its developer is legitimate. However it had reached the ethical boundary between justified monitoring and espionage. Today, keyloggers may be used for valid as well as malicious or criminal intent.

Detecting hardwired keyloggers require physical inspection of the area between the keyboard and the computer itself. On the other hand, detecting keylogger software requires knowledge of what it is and how it works. By nature, keyloggers work silently, giving the user no clue as to its existence. Not like virus attacks that blatantly announce their presence by affecting the machine's performance.

To avoid the attacks of keyloggers, it is strongly advised to have a system with proactive protection designed for detecting keylogger software. This means that users should ensure the their antivirus product's default settings detects these types of programs. If not, then the product should be configured accordingly to ensure protection against most of the common keyloggers. In short, detecting keylogger software means getting proactive protection that will protect the system against modifications made by keyloggers.

If you want to find out which anti-keylogger software is right for your needs, head over to the 'Keylogger Downloads' website, where you'll find anti-keylogger reviews, comparisons, user comments and user ratings. All of which will hopefully help you make an informed decision. TO find out more goto http://www.keyloggerdownloads.com/anti-keylogger-software.html Article Source: http://EzineArticles.com/?expert=Jimmy_A_Jones

• 0 komentar »

More and more people around the country are using the internet to find what they are looking for, whether it be a product or service. It used to be that the internet was really only used to find information or to spend time entertaining yourself, maybe even buy a product here and there. But over the last few years, people have been using the internet more and more to find what they are looking for, and this includes small businesses and the services they offer.

Most small businesses these days have a website to represent themselves online. These sites range anywhere from a few pages with a very simple layout to hundreds of pages and tons of features. If you are a realtor, you probably want a website design with a ton of content and features to allow your potential clients to browse homes and spend time learning about what you do and how you can help them. If you own an automotive repair shop, you probably don't need nearly the content that a realtor would need. Instead you would probably be more concerned with just have a nice clean looking website that is easy to navigate.

One thing is for sure, you want a professional web designer to develop your site for you. Unless you have extensive knowledge of programming and are knowledgeable enough about web design and the process to build a great looking site, it is strongly recommended to hire a professional web designer to build a great looking site for you.

The difference between a site builder designed site and a site designed with a custom template by a professional web designer can make all the difference in the world. Would you skimp on the appearance of your store front to save money? Then why would you skimp on your digital store front by trying to throw together your own website?

If you are interested in learning more about Fort Collins Web Design, please contact us by visiting our main site: Web Design. Article Source: http://EzineArticles.com/?expert=Mary_A_Jackson

• 0 komentar »

Flash website designs are the most sought after solutions for business that looks to attract its customers on web via a good-looking web identity. Flash, the force behind many multimedia projects, helps in spreading a message with the help of superior animations and graphic-rich solutions. No wonder, almost all new-media consultancies, advertising firms, and other companies who require effective designs look out for expert Flash designers.

Flash designs give the website a professional look - Now website designs are more established and they are created keeping in mind the user's point of view. They are founded on the content of the site. The users have to understand the products and the services of a particular website by its stance and that is the reason most people today opt for Flash website design. These designs are elegantly developed. The icons and images are used for highlighting vital points and content. These features keep audience completely engaged.

Most recently Flash website development companies propose to use light colors to complement the design they have made. Web designs are getting better with each day, providing a website a professional look. This look is more essential than stuffing of icons, images and other gears. Look for a flash website design company and make your presence felt in the field of online marketing website that is professionally designed.

Advantages of Flash designs - A good website layout gives extra visual effects, graphical feel, animations and a multimedia look to a website which would otherwise just be impossible. Flash has indefinite potential to create great website designs. Having Flash intro and Flash banners at your website is more or less vital in today competitive Internet setting. You have to stand out to be noticed and appreciated.

Unlike past years, flash web designing firms are now easy to find as they are increasing at a great speed. They have Flash web development solutions that suit the design needs of clients in spite of their diversified business specialties. Smart flash design solutions are available at very affordable rates.

This article is written by a technical writer, working at SynapseIndia, a Flash website developmentcompany that provides Flash website design services to worldwide clients. We have expertise inFlash web development to help our clients meet their specific needs. Article Source: http://EzineArticles.com/?expert=Jack_Davison

• 0 komentar »

Are you planning to launch your own website? If yes, then this article can definitely help you in planning your website design. Today, every business, be it is small or big needs to have a website for promoting the company effectively on an online platform. Also, when you are planning to make a website then various questions, thoughts and creative things pop up in your mind, which finally ends in creating confusion. But that confusion can be solved, if you follow some basic steps, while planning your website:

Domain Name

Before planning your website, you must create a domain i.e. your website address. The name of your domain should be simple and related to the nature of your work.

Keep the Content Simple

The content of the website should be kept simple as you don't want your clients to end up in confusion. Also, the content should be written according to your customers and their interest. There should be no unwanted content, or else your audience can get annoyed.

Dividing Each Section

Rather than simple content, the information of the each section should also be divided properly. Information of the different sections should be given on different pages, so that the person does not get perplexed and can attain grasp the relevant information from the particular section.

Colour Selection

Colour can be referred as a personal image. Also, colour selection of your website plays an important part in the website design. You have to select an appropriate colour for your website, but avoid using different colour schemes for a single website as it can look abrupt. Always use single colour scheme for your website.

Use Less Flash Videos and Pictures

A good site is the one, which operates very quickly and downloads the pages fastly. This can only happen, if you use limited flash videos, pictures and graphics. But, if your website has unnecessary flash videos and pictures, it will take a lot time to open. Also, use light graphics for your website design.

Follow these simple steps while planning your website design and be sure of attracting the maximum web traffic towards it.

Please Visit: http://www.mirageinternetsolutions.co.uk Mirage Internet Solutions is a leading UK based website designing company, providing web designing and web hosting services at very competitive and affordable prices in UK. Please visit our site: www.mirageinternetsolutions.co.uk. Article Source: http://EzineArticles.com/?expert=Sidharth_Marwah

• 0 komentar »

Sekilas Java

Akhmad Daniel Sembiring

Java adalah sebuah bahasa pemrograman komputer berbasiskan kepada Object Oriented Programming. Java diciptakan setelah C++ dan didesain sedemikian sehingga ukurannya kecil, sederhana, dan portable (dapat dipindah-pindahkan di antara bermacam platform dan sistem operasi). Program yang dihasilkan dengan bahasa Java dapat berupa applet (aplikasi kecil yang jalan di atas web browser) maupun berupa aplikasi mandiri yang dijalankan dengan program Java Interpreter. Contoh program yang ditulis dengan bahasa Java adalah HotJava yang berupa sebuah web browser.

1. Platform independence

Salah satu keunggulan Java adalah sifatnya yang 'platform independence', artinya Java - baik source program maupun hasil kompilasinya - sama sekali tidak bergantung kepada sistem operasi dan platform yang digunakan.  Source code sebuah aplikasi dengan bahasa Java yang ditulis di atas sistem Windows NT misalnya, dengan gampang dapat dipindahkan ke sistem operasi UNIX tanpa harus mengedit satu baris kode-pun. Ini tentunya merupakan satu nilai tambah tersendiri. Bandingkan dengan bahasa C/C++ misalnya, jika kita bekerja pada UNIX FreeBSD dan ingin memindahkannya pada HP UNIX, kita terkadang harus juga mengedit source code-nya sehingga sesuai dengan HP UNIX, walaupun keduanya masih berada dalam keluarga UNIX.

Dan yang lebih hebat lagi, bukan hanya source code-nya saja yang bisa dipindah-pindahkan antar sistem komputer, bahkan hasil kompilasinya pun bisa dijalankan di berbagai sistem komputer. Hal ini dimungkinkan dengan adanya bytecode. Setiap program yang ditulis dengan bahasa Java, hasil kompilasinya berupa bytecode, yaitu sekumpulan instruksi yang kelihatannya seperti kode mesin (machine code) tapi tidak spesifik untuk satu jenis prosesor tertentu.

Umumnya jika kita menulis program -misalnya dalam bahasa C++- pada satu sistem komputer -misalnya PC-, kompiler akan menterjemahkan source code kedalam bahasa mesin yang spesifik untuk prosesor yang ada di PC. Jika hendak dijalankan di sistem lain, Macintosh misalnya, maka source code harus dikompilasi lagi pada mesin Macintosh yang bersangkutan, dan terkadang harus melakukan pengeditan source code terlebih dahulu. Menjalankan hasil kompilasi dari platform Windows pada platform UNIX tidak akan pernah berhasil. Berikut ini ilustrasinya:

Hal yang berbeda terjadi pada lingkungan Java. Lingkungan Java terdiri dari dua bagian yaitu Java compiler dan Java interpreter. Java compiler menterjemahkan source code kedalam bytecode. Hasil kompilasi, yaitu program Java (berekstensi class), akan bisa dijalankan dengan bantuan Java interpreter. Java interpreter dapat dijalankan langsung (dari command prompt) maupun dari program applet viewer atau web browser (untuk applet). Kenapa harus bersusah payah menambahkan satu layer bytecode interpreter? Jawabnya adalah untuk memungkinkan program Java bisa dijalankan pada bermacam-macam sistem komputer asalkan pada sistem komputer itu terdapat Java interpreter.

Kelemahan dari penggunaan bytecode adalah kecepatan operasi yang lebih lambat daripada program-program biasa. Hal ini karena program-program yang ditulis pada bahasa pemrograman yang hardware-specific dapat langsung berjalan di atas hardware dimana ia dikompilasi.. Program bytecode harus diterjemahkan terlebih dahulu oleh interpreter baru dijalankan di atas hardware.

Karena keunggulan-keunggulan di atas, program Java sangat baik digunakan untuk aplikasi internet maupun intranet, mengingat komunitasi internet dan intranet biasanya menggunakan sistem operasi dan platform yang sangat berbeda-beda dalam mendapatkan dan memberikan informasi.

1. Memulai Java

Untuk bisa memulai menggunakan Java, minimal kita harus terlebih dahulu menginstall Java Development Kit yang dapat di-download dengan gratis dari http://java.sun.com. Dapat juga digunakan program developent tools Java lainnya yang memiliki fasilitas yang lebih lengkap seperti Symantec Café, Borland J Builder, Microsoft Visual J++, dan lainnya.

Seperti telah diterangkan di atas, hasil kompilasi Java dapat berupa aplikasi maupun applet. Aplikasi merupakan hasil kompilasi program Java yang dapat langsung dijalankan dari command prompt dengan bantuan program java interpreter, sedangkan applet harus dijalankan di atas browser atau appletviewer. Perbedaan applet dan aplikasi Java terletak pada penurunannya dari class Applet. Perhatikan contoh di bawah ini:

Pada aplikasi Java, kita membuat sebuah class baru yang bukan merupakan turunan dari class apapun. Apa yang akan dikerjakan oleh aplikasi tersebut terletak di dalam prosedur main. Dalam contoh di atas, aplikasi akan mencetak tulisan “Halo, ini Aplikasi java saya yang pertama!” pada layar monitor (diwakili oleh objek System.out). Setelah dikompilasi kita akan mendapatkan bytecode yang berada dalam bentuk file  dengan ekstensi class. Hal yang perlu diperhatikan adalah bahwa:

1.       nama file source code harus sama dengan nama class yang didefinisikan di atas (dalam hal ini JavaPertama.java)

2.       penamaan dan penulisan syntaks dalam Java adalah case sensitive

3.       nama file bytecode hasil kompilasi sama dengan nama class yang didefinisikan (dalam hal ini JavaPertama.class)

Sedangkan pada applet terdapat baris class JavaAppletPertama extends java.applet.Applet yang menentukan bahwa class yang baru kita buat (JavaAppletPertama) merupakan turunan dari class Applet yang berada pada paket java.applet. Salah satu yang menarik dari Java adalah telah tersedianya sedemikian banyak class yang siap pakai dan tinggal diturunkan (baca: digunakan) untuk membuat applet maupun aplikasi baru. Kumpulan class-class ini disimpan dalam suatu paket yang diakses dengan memanggil nama paket yang bersangutan. Paket-paket ini telah meliputi paket bahasa Java dasar (java.lang), paket abstraksi window dan objek-objeknya (java.awt), sampai dengan paket networking TCP/IP (java.net).

Setelah diturunkan dari class Applet, class yang baru akan secara otomatis memiliki sifat (attribute) dan kelakuan (behaviour) yang sama dengan class Applet. Namun class Applet ini baru hanya merupakan template untuk pembuatan applet-applet baru. Kita harus melakukan modifikasi (istilahnya overriding) terhadap prosedur dan fungsi yang tersedia dari class Applet. Salah satu prosedur  yang akan kita override pada contoh ini adalah prosedur paint() yang menentukan bagaimana dan apa yang akan ditampilkan pada applet saat pertama kali muncul.

Pada applet di atas kita juga menggunakan class Graphics yang gunanya untuk manipulasi tampilan Graphics pada applet kita. Untuk itu kita harus secara eksplisit memanggil class tersebut dengan nama tempat paketnya, yaitu: import java.awt.Graphics.

Lalu pada prosedur paint(), kita lakukan penggambaran sesuatu pada applet dengan menggunakan function drawString() yang terletak pada objek g yang bertype Graphics. Function ini mengambil parameter string apa yang akan digambarkan, posisi x, dan posisi y (dalam pixel) pada applet.

Setelah dikompilasi, kita akan memperoleh sebuah file class yang bernama JavaAppletPertama.class. Untuk melihat hasil applet tersebut, kita harus membuat sebuah halaman HTML yang memanggil applet tersebut. Gunakan tag HTML <applet> </applet> sebagai berikut:

<HTML>

<HEAD>

<TITLE> Percobaan membuat applet </TITLE>

</HEAD>

<BODY>

Java applet ku mengatakan:

<APPLET CODE="JavaAppletPertama.class" WIDTH=150  HEIGHT=25></APPLET>

</BODY>

</HTML>

Sekarang jalankan web browser dan buka file HTML ini (misalnya applet.html) dan lihat hasilnya. Cara lain untuk melihat applet ini adalah dengan menggunakan program appletviewer yang merupakan program bawaan Java Development Kit.

1.                 Informasi lebih lanjut

Salah satu keuggulan Java adalah kemampuannya dijalankan pada web browser ini. Dalam hal ini web browser berfungsi sebagai Java Interpreter yang berfungsi menterjemahkan bytecode dan menampilkan hasilnya pada browser. Ini berarti kita akan mendapatkan tampilan halaman web yang animatif, dinamis, maupun interaktif, tergantung dari program Java yang dibuat. Tanpa Java, kita hanya akan mendapat tampilan dokumen HTML yang statis, tidak menarik dan tidak interaktif. Banyak contoh applet yang tersedia di internet yang telah siap digunakan untuk memperindah dan membuat halaman web anda lebih interaktif. Sebagian ada yang gratis dan ada pula yang harus anda beli. Silahkan kunjungi search engine dengan keyword java, class, atau java class. Site lain yang layak anda kunjungi adalah http://www.developer.com dan http://java.sun.com

Untuk mempelajari Java lebih detail, sekarang  terdapat banyak literatur baik yang ada di internet maupun di buku. Salah satunya adalah “Java dan JavaScript” oleh Onno W. Purbo & Akhmad Daniel S, PT Elex Media Komputindo 1998.

• 0 komentar »

Primary Key
adalah batasan yang memaksakan integritas, entitas untuk kolom tertentu melalui index unik.
hanya ada satu batasan primary key yang bisa dibuat pertabel.

Foreign key references
merupakan batasan yang menyediakan integritas, referencial untuk data pada kolom.
batasan foreign key menghendaki agar setiap nilai pada kolom, terdapat pada kolom-kolom yang sesuai pada tabel-tabel yang dirujuk.
batasan foreign key hanya bisa merujuk kolom-kolom yang memiliki batasan primary key, atau unik pada tabel yang dirujuk.

Cara buat diagram tabel:
klik kanan pada database
pilih new
pilih new diagram tabel
klik next dan add semua nama tabel.

• 0 komentar »

USE PBD;

CREATE TABLE MAHASISWA(
THANG INTEGER NOT NULL,
NIM INTEGER NOT NULL,
NAMA VARCHAR (30) NOT NULL,
ALAMAT VARCHAR (80) DEFAULT 'YOGYA',
TGL DATETIME);
ALTER TABLE MAHASISWA ADD CONSTRAINT PK_MHS PRIMARY KEY (NIM);

CREATE TABLE DOSEN (
NIP INTEGER NOT NULL PRIMARY KEY,
NAMA VARCHAR(30)NOT NULL);

CREATE TABLE MATAKULIAH (
KODE CHAR(2) NOT NULL PRIMARY KEY,
MATAKULIAH VARCHAR(30) NOT NULL,
SKS INTEGER DEFAULT 2);

CREATE TABLE KELAS (
IDKELAS INTEGER IDENTITY (0,1) PRIMARY KEY,
KODE CHAR (2) NOT NULL,
NIP INTEGER NOT NULL);

ALTER TABLE KELAS ADD CONSTRAINT FK_KELAS1 FOREIGN KEY (KODE)
REFERENCES MATAKULIAH (KODE)
ON UPDATE CASCADE
ON DELETE NO ACTION;

ALTER TABLE KELAS ADD CONSTRAINT FK_KELAS2 FOREIGN KEY (NIP)
REFERENCES DOSEN (NIP)
ON UPDATE CASCADE
ON DELETE NO ACTION;

CREATE TABLE KRS (
NIM INTEGER NOT NULL,
IDKELAS INTEGER NOT NULL,
NILAI INTEGER DEFAULT 0,
PRIMARY KEY (NIM, IDKELAS));

ALTER TABLE KRS ADD CONSTRAINT FK_KRS1 FOREIGN KEY (NIM)
REFERENCES MAHASISWA (NIM)
ON UPDATE CASCADE
ON DELETE NO ACTION;

ALTER TABLE KRS ADD CONSTRAINT FK_KRS2 FOREIGN KEY (IDKELAS)
REFERENCES KELAS (IDKELAS)
ON UPDATE CASCADE
ON DELETE NO ACTION;

• 0 komentar »