javajavascriptjavax.script

Converting a JavaScript array to a Java array

I'm trying to convert a JavaScript array in Java to a Java array. I'm using the javax.script package.

I tested this example here, but the type NativeArray was not recognized: https://stackoverflow.com/a/1433489/975097

How can I get the NativeArray type to be recognized?

Solution

  • Per this answer it looks like your best bet is to write a JavaScript converter function which transforms the native JavaScript array into a Java array using Rhino's Java binding functionality. Note that you'll have to take some care to use the correct type when converting the individual elements.

    [Edit] Here's a working example using a string array:

    ScriptEngine js = new ScriptEngineManager().getEngineByName("JavaScript");
String ss[] = (String[]) js.eval(
    "(function() {" +
    "  var a = java.lang.reflect.Array.newInstance(java.lang.String, 3);" +
    "  a[0] = 'foo';" +
    "  a[1] = 'bar';" +
    "  a[2] = 'gah';" +
    "  return a;" +
    "})()");
System.out.println(Arrays.toString(ss)); // => [foo, bar, gah]