Why use Java?

It may interest us if we want to create programs that have to work in different operating systems without any changes, or client / server programs, or applications for an Android Smartphone, among other cases.

When not to use Java?

As there must be an intermediate step that is the JVM to run a Java program, we can not use programs written in this programming language for a system that does not have the Java virtual machine installed. Neither do we need our program to run at the maximum possible speed, maybe the JVM slows down the process a bit because there is an intermediate step between the program and the processor. Java does not allow low-level programming like other programming languages.

What else does Java bring?

The Java programming language has many interesting features, which have made it one of the most popular languages.

• The syntax of the language is very similar to that of C++, C, C#, PHP and some other. This simplifies Java learning if you know any of these languages, and also allows you to take advantage of Java knowledge to learn one of these other languages ​​later.
• It is an object-oriented language (OOP), which will mean advantages when designing and maintaining large programs.
• It allows to create «multitasking» programs (formed by several threads of execution), which helps to take advantage of modern processors with multiple cores.
• It includes exception control, as a simpler alternative to handle unexpected errors, such as a nonexistent file or a lost network connection.
• It is more difficult to make programming errors than in other languages, such as C and C++, Java have no pointers, which are a source of headaches in these languages.
• You can create programs in text mode, window-based environments, draw graphics, access databases, etc.

What does it take to use a program created in Java?

The computer where we want to run a program written in Java needs a Java interpreter, the famous virtual machine or JVM. Normally the Linux and Android operating systems already bring it installed by defect, but if we did not have it as it can happen in Windows, just install the «Java Runtime Enviroment» (JRE), which can be downloaded freely from Java.com.

We can also find programs created in Java language within Web pages. These Java applications included in a Web page are called «Applets», and to use them we should also have installed the Java virtual machine.

What does it take to create a program in Java?

There are several tools that will allow us to create programs in Java. Oracle itself supplies an official development kit that is known as JDK (Java Development Kit). It is freely distributed and can be obtained on Oracle’s own website.

The drawback of the JDK is that it does not include an editor to create our programs, only the tools to generate the executable program and to test it.

Therefore, it can be uncomfortable to manage for those who are used to other integrated environments, such as Visual C# and Visual Basic, which incorporate powerful editors. But it’s not a big problem, because it’s easy to find editors that make our work easier, or even complete development systems, like Eclipse or NetBeans. Both are good and free.