This is an example of how to evaluate a simple script in Java. We are using the ScriptEngine interface, that provides methods for basic scripting functionality. Applications written to this simple interface are expected to work with minimal modifications in every implementation. It includes methods that execute scripts, and ones that set and get values. Evaluating a script implies that you should:
- Create a new ScriptEngineManager. The ScriptEngineManager implements a discovery and instantiation mechanism for ScriptEngine classes and also maintains a collection of key/value pairs storing state shared by all engines created by the Manager.
- Use the
getEngineByExtension(String extension)method to look up and create a ScriptEngine for a given extension. - Use the
eval(String script)method to execute a script.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
public class EvaluateScriptExample {
public static void main(String[] args) {
// Create script engine instance and get extension
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine js = manager.getEngineByExtension("js");
try {
// Evaluate script
js.eval("print('Hello JavaCodeGeeks Fellow')");
} catch (ScriptException e) {
e.printStackTrace();
}
}
}
Output:
Hello JavaCodeGeeks Fellow
This was an example of how to evaluate a simple script in Java.
