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Although JAVA, being an object-oriented programming language, is used to build applications widely across the world, it does not suit all purposes or match all requirements. In those cases, it is imperative that JAVA takes the help of dynamic languages by including their scripts and running it on the JAVA Virtual Machine (JVM). The Java Scripting Application Programming Interface facilitates the process by assisting in integrating dynamic language scripts with JAVA. The Scripting API brings with it a small set of concrete classes and interfaces that make it possible to interact with and use dynamic language scripts in Java applications.
With the update of JAVA SE in 2006, this all-important scripting package that would let JAVA collaborate with dynamic scripts was added. This gave a huge boost to independent language developers who thereafter will be able to link their script with JAVA and invoke functions with the help of a common API. The JAVA Scripting API uses the structure of two-way visibility for dynamic language scripts. In this mechanism, it allows external scripts the freedom to access certain JAVA objects alongside integrations. A simple example would be the Ruby Script. This script has permission to modify behaviours of objects by invoking methods on them.
When to use JAVA Scripting API?
The main focus of this API is the ability to integrate and collaborate with external language scripts. Therefore, the JAVA Scripting API will find the best use when you have an external language script that wants to invoke method calls on your JAVA program. Dynamic language developers use this API the most to integrate with JAVA thereby providing an opportunity to learn about the language’s interpreter. Another important feature of this API is that you can avoid the ‘compile’ section and directly run the code after editing it. Therefore, it is possible to create instant prototypes using this construct.
How to Use the Java Scripting API
This API uses classes and interfaces of the ‘javax.script’ package. In order to implement it, there are three simple steps:
- After importing the package, you will need to create a ‘ScriptEngineManager’ object.
- From the manager, obtain a ScriptEngine object.
- The ScriptEngine object has an eval() method that is pre-defined. Use it to examine the script at hand.