[java] What are native methods in Java and where should they be used?

A native method has the same syntax as an abstract method, but where is it implemented?

Native methods allow you to use code from other languages such as C or C++ in your java code. You use them when java doesn't provide the functionality that you need. For example, if I were writing a program to calculate some equation and create a line graph of it, I would use java, because it is the language I am best in. However, I am also proficient in C. Say in part of my program I need to calculate a really complex equation. I would use a native method for this, because I know some C++ and I know that C++ is much faster than java, so if I wrote my method in C++ it would be quicker. Also, say I want to interact with another program or device. This would also use a native method, because C++ has something called pointers, which would let me do that.

I like to know where does we use Native Methods

Ideally, not at all. In reality some functionality is not available in Java and you have to call some C code.

The methods are implemented in C code.

The method is implemented in "native" code. That is, code that does not run in the JVM. It's typically written in C or C++.

Native methods are usually used to interface with system calls or libraries written in other programming languages.

Java native code necessities:

• h/w access and control.
• use of commercial s/w and system services[h/w related].
• use of legacy s/w that hasn't or cannot be ported to Java.
• Using native code to perform time-critical tasks.

hope these points answers your question :)