模块  jdk.scripting.nashorn

Package jdk.nashorn.api.tree

Nashorn parser API provides interfaces to represent ECMAScript source code as abstract syntax trees (AST) and Parser to parse ECMAScript source scripts.

Using parser API user can write Java code to access parse tree representation of ECMAScript source. Script source may be a file, a URL or a String. Unless stated otherwise null argument in methods of this package result in NullPointerException being thrown. 

 import jdk.nashorn.api.tree.*; import java.io.File; // Simple example that prints warning on 'with' statements public class Main {     public static void main(String[] args) throws Exception {         // Create a new parser instance         Parser parser = Parser.create();         File sourceFile = new File(args[0]);         // Parse given source File using parse method.         // Pass a diagnostic listener to print error messages.         CompilationUnitTree cut = parser.parse(sourceFile,             (d) -> { System.out.println(d); });         if (cut != null) {             // call Tree.accept method passing a SimpleTreeVisitor             cut.accept(new SimpleTreeVisitor<Void, Void>() {                 // visit method for 'with' statement                 public Void visitWith(WithTree wt, Void v) {                     // print warning on 'with' statement                     System.out.println("Warning: using 'with' statement!");                     return null;                 }             }, null);         }     } }
从以下版本开始：
9