--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/javafoovars.js	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,102 @@
+#// Usage: jjs javafoovars.js -- <directory>
+
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// This example demonstrates Java subclassing by Java.extend
+// and javac Compiler and Tree API. This example counts number
+// of variables called "foo" in the given java source files!
+if (arguments.length == 0) {
+    print("Usage: jjs javafoovars.js -- <directory>");
+    exit(1);
+}
+
+// Java types used
+var File = Java.type("java.io.File");
+var Files = Java.type("java.nio.file.Files");
+var StringArray = Java.type("java.lang.String[]");
+var ToolProvider = Java.type("javax.tools.ToolProvider");
+var Tree = Java.type("com.sun.source.tree.Tree");
+var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
+var VariableTree = Java.type("com.sun.source.tree.VariableTree");
+
+// count "foo"-s in the given .java files
+function countFoo() {
+    // get the system compiler tool
+    var compiler = ToolProvider.systemJavaCompiler;
+    // get standard file manager
+    var fileMgr = compiler.getStandardFileManager(null, null, null);
+    // Using Java.to convert script array (arguments) to a Java String[]
+    var compUnits = fileMgr.getJavaFileObjects(
+        Java.to(arguments, StringArray));
+    // create a new compilation task
+    var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);
+    // subclass SimpleTreeVisitor - to count variables called "foo"
+    var FooCounterVisitor = Java.extend(TreeScanner);
+    var fooCount = 0;
+
+    var visitor = new FooCounterVisitor() {
+        visitVariable: function (node, p) {
+            if (node.name.toString() == "foo") {
+                fooCount++;
+            }
+        }
+    }
+
+    for each (var cu in task.parse()) {
+        cu.accept(visitor, null);
+    }
+    return fooCount;
+}
+
+// for each ".java" file in directory (recursively) count "foo".
+function main(dir) {
+    var totalCount = 0;
+    Files.walk(dir.toPath()).
+      forEach(function(p) {
+        var name = p.toFile().absolutePath;
+        if (name.endsWith(".java")) {
+            var count = 0;
+            try {
+                count = countFoo(p.toFile().getAbsolutePath());
+            } catch (e) {
+                print(e);
+            }
+            if (count != 0) {
+                print(name + ": " + count);
+            }
+            totalCount += count;
+        }
+      });
+    print("Total foo count: " + totalCount);
+}
+
+main(new File(arguments[0]));