Native Code Compiler for Java

What Does Native Code Compiler for Java Mean?

Native code compiler for Java (NCCJ) is a compiler application that converts Java code to a native code that can be executed without the need for interpreters. Native code compiler for Java translates the Java code into a binary representation that can be linked to precompiled library files and resources to create an executable program.

Techopedia Explains Native Code Compiler for Java

Java code is usually converted into an intermediate byte code, which is then compiled into a machine-dependent code with the help of JVM running on each machine where the program is to be executed. This particular feature of Java makes Java programs more flexible and portable across a wide range of devices. But this introduces an overhead and may cause Java programs to take more time than natively compiled code. As the primary design concern for Java as to make it a platform-independent and secure development model, the execution performance lag due to the byte code feature was sidelined.

But when developers want to improve execution performance, they may choose to natively compile the Java classes or certain parts of the code. Native code compilers for Java help to achieve this, and thus help to achieve better processing speed than the byte code interpretation.

The increase in speed may occur due to several factors, such as:

Use of numerics
Degree of polymorphic message
Direct field access
Amount of array accessing
Casts

The two major types of native code compilers are just-in-time (JIT) compilers and ahead-of-time (AOT) compilers. JIT compilers allow the JVM to translate Java code to machine code as and when needed by the JDK. AOT compilers compile the Java code within a JAR file into native shared libraries before the execution time.

Native compile code is also known as static compilation and provides a consistent performance.