src/sample/nashorn/autoimports.js
changeset 47216 71c04702a3d5
parent 31096 a3a697c1edd5
child 47286 cd02250e9370
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/autoimports.js	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,151 @@
+# autoimports script requires -scripting mode
+
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+/*
+ * It is tedious to import Java classes used in a script. Sometimes it is easier
+ * use simple names of java classes and have a script auto import Java classes. 
+ * You can load this script at the start of an interactive jjs session or at the
+ * start of your script. This script defines a __noSuchProperty__ hook to auto 
+ * import Java classes as needed and when they are referred to for the first time
+ * in your script. You can also call the "autoimports" function to print script 
+ * statements that you need to use in your script, i.e., have the function generate
+ * a script to import Java classes used by your script so far. After running your
+ * script, you can call autoimports to get the exact Java imports you need and replace
+ * the autoimports load with the generated import statements (to avoid costly init of
+ * the autoimports script).
+ */
+
+(function() {
+    var ArrayList = Java.type("java.util.ArrayList");
+    var HashMap = Java.type("java.util.HashMap");
+    var Files = Java.type("java.nio.file.Files");
+    var FileSystems = Java.type("java.nio.file.FileSystems");
+    var URI = Java.type("java.net.URI");
+
+    // initialize a class to package map by iterating all
+    // classes available in the system by walking through "jrt fs"
+    var fs = FileSystems.getFileSystem(URI.create("jrt:/"));
+    var root = fs.getPath('/');
+
+    var clsToPkg = new HashMap();
+
+    function addToClsToPkg(c, p) {
+        if (clsToPkg.containsKey(c)) {
+            var val = clsToPkg.get(c);
+            if (val instanceof ArrayList) {
+                val.add(p);
+            } else {
+                var al = new ArrayList();
+                al.add(val);
+                al.add(p);
+                clsToPkg.put(c, al);
+            }
+        } else {
+            clsToPkg.put(c, p);
+        }
+    }
+
+    // handle collision and allow user to choose package
+    function getPkgOfCls(c) {
+        var val = clsToPkg.get(c);
+        if (val instanceof ArrayList) {
+            var count = 1;
+            print("Multiple matches for " + c + ", choose package:");
+            for each (var v in val) {
+                print(count + ". " + v);
+                count++;
+            }
+            var choice = parseInt(readLine());
+            if (isNaN(choice) || choice < 1 || choice > val.size()) {
+                print("invalid choice: " + choice);
+                return undefined;
+            }
+            return val.get(choice - 1);
+        } else {
+            return val;
+        }
+    }
+
+    Files.walk(root).forEach(function(p) {
+        if (Files.isRegularFile(p)) {
+            var str = p.toString();
+            if (str.endsWith(".class")) {
+                str = str.substring(1);
+                var idx = str.indexOf('/');
+                if (idx != -1) {
+                    str = str.substring(idx + 1);
+                    if (str.startsWith("java") ||
+                        str.startsWith("javax") ||
+                        str.startsWith("org")) {
+                        var lastIdx = str.lastIndexOf('/');
+                        if (lastIdx != -1) {
+                            var pkg = str.substring(0, lastIdx).replaceAll('/', '.');
+                            var cls = str.substring(lastIdx + 1, str.lastIndexOf(".class"));
+                            addToClsToPkg(cls, pkg);
+                        }
+                    }
+                }
+            }
+        } 
+    });
+
+    var imports = new ArrayList();
+    var global = this;
+    var oldNoSuchProp = global.__noSuchProperty__;
+    this.__noSuchProperty__ = function(name) {
+        'use strict';
+
+        if (clsToPkg.containsKey(name)) {
+            var pkg = getPkgOfCls(name);
+            if (pkg) {
+                var clsName = pkg + "." + name;
+                imports.add("var " + name + " = Java.type('" + clsName + "');");
+                return global[name] = Java.type(clsName);
+            }
+        } else if (typeof oldNoSuchProp == 'function') {
+            return oldNoSuchProp.call(this, name);
+        }
+
+        if (typeof this == 'undefined') {
+            throw new ReferenceError(name);
+        } else {
+            return undefined;
+        }
+    }
+
+    this.autoimports = function() {
+        for each (var im in imports) {
+            print(im);
+        }
+    }
+})();