This example demonstrate how to evaluate script that stored on a file. As we know that the eval()
method can also accept a Reader
object we can then read the script file using FileReader
and pass it as the parameter to the eval()
method of the ScriptEngine
for further evaluation.
package org.kodejava.example.script;
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
import java.io.File;
import java.io.Reader;
import java.io.FileReader;
import java.io.FileNotFoundException;
public class EvalScriptFile {
public static void main(String[] args) {
// Obtaining ECMAScript / JavaScript ScriptEngine.
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("ECMAScript");
try {
// Create an instance of File object that point to our
// scripting file. An create a FileReader to read the
// file to be passed to the ScriptEngine.eval() method.
//
// The file need to be placed in the same folder with
// our class so it enable to read it. We can define the
// full path to the file also to make easier for the
// Reader to find it.
File script = new File("helloworld.js");
Reader reader = new FileReader(script);
engine.eval(reader);
} catch (FileNotFoundException | ScriptException e) {
e.printStackTrace();
}
}
}
Latest posts by Wayan (see all)
- How do I create a generic class in Java? - January 1, 2021
- How do I convert java.util.TimeZone to java.time.ZoneId? - April 25, 2020
- How do I get a list of all TimeZones Ids using Java 8? - April 25, 2020