loading file twice locks the file

[Sundararajan Athijegannathan]

Will you please file a bug with test case attached?

Thanks,
-Sundar

On 01/02/18, 6:49 PM, yikes aroni wrote:
> I find that, when i load a javascript file in java *twice *using this
> pattern
>
> ScriptObjectMirror som = 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. Furthermore, this happens even if i null out the
> resulting ScriptObjectMirrors. My question is: how can I avoid this? I need
> to be able to load the file and get the resulting ScriptObjectMirror
> multiple times and be able to delete the source file.
>
> Is Nashorn not properly closing a stream?  It's odd that it doesn't lock
> the file for the first SOM, but does for the second (and subsequent)
> SOMs....
>
> Try it with this code. Instructions:
>
> 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();
> }
> }
> }