FULL PRODUCT VERSION :
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)

and

java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
When you use the "load" function from within java to load a javascript file *twice * using this pattern

          scriptEngine.eval("load('c:/temp/test.js');");


it locks the JS file (prevents its deletion). This does NOT happen if i load the file only once.

It does not appear to matter whether i assign the result of the load or null out the assigned variable nor to wait until some gc has occurred.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) Create a file "test.js" and put it where you want. I put it in
c:\temp\test.js

(function(module) {
var exports = module.exports;
exports.test = function() {
return "test ok";
}
return module.exports;})({exports:{}, id:'test'});


2) Create a Temp.java as follows and run it first with *loadSecondSom =
true*. The deletion will fail. Then run it with *loadSecondSom = false*.
The deletion will succeed. (Note: the "pause" is only to make it clearer...)

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import javax.script.ScriptEngine;
import javax.script.ScriptException;

import jdk.nashorn.api.scripting.NashornScriptEngineFactory;
import jdk.nashorn.api.scripting.ScriptObjectMirror;

public class Temp {
private static final NashornScriptEngineFactory nashornFactory = new
NashornScriptEngineFactory();
private static ScriptEngine scriptEngine = nashornFactory.getScriptEngine();

private static void deleteFile(String sPath) throws IOException {
Path p = Paths.get(sPath);
Files.delete(p);
}
private static void pause(int numsecs) {
int x;
try {
for (int i=0;i<numsecs;i++) {
Thread.sleep(1000);
x = i;
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}

public static void main(String[] ss) {
boolean loadSecondSom = true;
String sPath = "C:/temp/test.js";
try {
System.out.println("loading and calling som1...");
ScriptObjectMirror som1 = (ScriptObjectMirror)scriptEngine.eval("load('" +
sPath + "');");
System.out.println(som1.callMember("test"));
System.out.println("Sleeping ... ");
pause(2);
if (loadSecondSom) {
System.out.println("loading and calling som2...");
ScriptObjectMirror som2 = (ScriptObjectMirror)scriptEngine.eval("load('" +
sPath + "');");
System.out.println(som2.callMember("test"));
}

System.out.println("Sleeping ... ");
pause(2);

System.out.println("Attempting to delete the file from the fs...");
try {
deleteFile(sPath);
} catch (IOException e) {
System.out.println("Cannot delete the file: "+e);
}

System.out.println("DONE");
} catch (ScriptException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expect the file to be deleted on the file system.
ACTUAL -
An exception is thrown indicating that the file is locked:

java.nio.file.FileSystemException: C:\temp\test.js: The process cannot access the file because it is being used by another process.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.nio.file.FileSystemException: C:\temp\test.js: The process cannot access the file because it is being used by another process.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
NOTE: you must first place the Javascript file test.js in the c:\temp directory (or somewhere on the file system) and ensure the path in the following source is correct. Please see the "Steps to Reproduce" for the simple steps.

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import javax.script.ScriptEngine;
import javax.script.ScriptException;

import jdk.nashorn.api.scripting.NashornScriptEngineFactory;
import jdk.nashorn.api.scripting.ScriptObjectMirror;

public class Temp {
private static final NashornScriptEngineFactory nashornFactory = new
NashornScriptEngineFactory();
private static ScriptEngine scriptEngine = nashornFactory.getScriptEngine();

private static void deleteFile(String sPath) throws IOException {
Path p = Paths.get(sPath);
Files.delete(p);
}
private static void pause(int numsecs) {
int x;
try {
for (int i=0;i<numsecs;i++) {
Thread.sleep(1000);
x = i;
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}

public static void main(String[] ss) {
boolean loadSecondSom = true;
String sPath = "C:/temp/test.js";
try {
System.out.println("loading and calling som1...");
ScriptObjectMirror som1 = (ScriptObjectMirror)scriptEngine.eval("load('" +
sPath + "');");
System.out.println(som1.callMember("test"));
System.out.println("Sleeping ... ");
pause(2);
if (loadSecondSom) {
System.out.println("loading and calling som2...");
ScriptObjectMirror som2 = (ScriptObjectMirror)scriptEngine.eval("load('" +
sPath + "');");
System.out.println(som2.callMember("test"));
}

System.out.println("Sleeping ... ");
pause(2);

System.out.println("Attempting to delete the file from the fs...");
try {
deleteFile(sPath);
} catch (IOException e) {
System.out.println("Cannot delete the file: "+e);
}

System.out.println("DONE");
} catch (ScriptException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
i have not found one.