jlaskey - Developer IT

Welcome To The Nashorn Blog

- by jlaskey

Welcome to all. Time to break the ice and instantiate The Nashorn Blog. I hope to contribute routinely, but we are very busy, at this point, preparing for the next development milestone and, of course, getting ready for open source. So, if there are long gaps between postings please forgive. We're just coming back from JavaOne and are stoked by the positive response to all the Nashorn sessions. It was great for the team to have the front and centre slide from Georges Saab early in the keynote. It seems we have support coming from all directions. Most of the session videos are posted. Check out the links. Nashorn: Optimizing JavaScript and Dynamic Language Execution on the JVM. Unfortunately, Marcus - the code generation juggernaut, got saddled with the first session of the first day. Still, he had a decent turnout. The talk focused on issues relating to optimizations we did to get good performance from the JVM. Much yet to be done but looking good. Nashorn: JavaScript on the JVM. This was the main talk about Nashorn. I delivered the little bit of this and a little bit of that session with an overview, a follow up on the open source announcement, a run through a few of the Nashorn features and some demos. The room was SRO, about 250±. High points: Sam Pullara, from Twitter, came forward to describe how painless it was to get Mustache.js up and running (20x over Rhino), and, John Ceccarelli, from NetBeans came forward to describe how Nashorn has become an integral part of Netbeans. A healthy Q & A at the end was very encouraging. Meet the Nashorn JavaScript Team. Michel, Attila, Marcus and myself hosted a Q & A. There was only a handful of people in the room (we assume it was because of a conflicting session ;-) .) Most of the questions centred around Node.jar, which leads me to believe, Nashorn + Node.jar is what has the most interest. Akhil, Mr. Node.jar, sitting in the audience, fielded the Node.jar questions. Nashorn, Node, and Java Persistence. Doug Clarke, Akhil and myself, discussed the title topics, followed by a lengthy Q & A (security had to hustle us out.) 80 or so in the room. Lots of questions about Node.jar. It was great to see Doug's use of Nashorn + JPA. Nashorn in action, with such elegance and grace. Putting the Metaobject Protocol to Work: Nashorn’s Java Bindings. Attila discussed how he applied Dynalink to Nashorn. Good turn out for this session as well. I have a feeling that once people discover and embrace this hidden gem, great things will happen for all languages running on the JVM. Finally, there were quite a few JavaOne sessions that focused on non-Java languages and their impact on the JVM. I've always believed that one's tool belt should carry a variety of programming languages, not just for domain/task applicability, but also to enhance your thinking and approaches to problem solving. For the most part, future blog entries will focus on 'how to' in Nashorn, but if you have any suggestions for topics you want discussed, please drop a line. Cheers.

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Nashorn in the Twitterverse, Continued

- by jlaskey

After doing the Twitter example, it seemed reasonable to try graphing the result with JavaFX. At this time the Nashorn project doesn't have an JavaFX shell, so we have to go through some hoops to create an JavaFX application. I thought showing you some of those hoops might give you some idea about what you can do mixing Nashorn and Java (we'll add a JavaFX shell to the todo list.) First, let's look at the meat of the application. Here is the repackaged version of the original twitter example. var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; function getTrendingData() { var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.since("2012-11-21"); query.count = 100; var data = {}; do { var result = twitter.search(query); var tweets = result.tweets; for each (tweet in tweets) { var date = tweet.createdAt; var key = (1900 + date.year) + "/" + (1 + date.month) + "/" + date.date; data[key] = (data[key] || 0) + 1; } } while (query = result.nextQuery()); return data; } Instead of just printing out tweets, getTrendingData tallies "tweets per date" during the sample period (since "2012-11-21", the date "New Project: Nashorn" was posted.) getTrendingData then returns the resulting tally object. Next, use JavaFX BarChart to display that data. var javafx = Packages.javafx; var Stage = javafx.stage.Stage var Scene = javafx.scene.Scene; var Group = javafx.scene.Group; var Chart = javafx.scene.chart.Chart; var FXCollections = javafx.collections.FXCollections; var ObservableList = javafx.collections.ObservableList; var CategoryAxis = javafx.scene.chart.CategoryAxis; var NumberAxis = javafx.scene.chart.NumberAxis; var BarChart = javafx.scene.chart.BarChart; var XYChart = javafx.scene.chart.XYChart; var Series = XYChart.Series; var Data = XYChart.Data; function graph(stage, data) { var root = new Group(); stage.scene = new Scene(root); var dates = Object.keys(data); var xAxis = new CategoryAxis(); xAxis.categories = FXCollections.observableArrayList(dates); var yAxis = new NumberAxis("Tweets", 0.0, 200.0, 50.0); var series = FXCollections.observableArrayList(); for (var date in data) { series.add(new Data(date, data[date])); } var tweets = new Series("Tweets", series); var barChartData = FXCollections.observableArrayList(tweets); var chart = new BarChart(xAxis, yAxis, barChartData, 25.0); root.children.add(chart); } I should point out that there is a lot of subtlety going on in the background. For example; stage.scene = new Scene(root) is equivalent to stage.setScene(new Scene(root)). If Nashorn can't find a property (scene), then it searches (via Dynalink) for the Java Beans equivalent (setScene.) Also note, that Nashorn is magically handling the generic class FXCollections. Finally, with the call to observableArrayList(dates), Nashorn is automatically converting the JavaScript array dates to a Java collection. It really is hard to identify which objects are JavaScript and which are Java. Does it really matter? Okay, with the meat out of the way, let's talk about the hoops. When working with JavaFX, you start with a main subclass of javafx.application.Application. This class handles the initialization of the JavaFX libraries and the event processing. This is what I used for this example; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import javafx.application.Application; import javafx.stage.Stage; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; public class TrendingMain extends Application { private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); private Trending trending; public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) throws Exception { trending = (Trending) load("Trending.js"); trending.start(stage); } @Override public void stop() throws Exception { trending.stop(); } private Object load(String script) throws IOException, ScriptException { try (final InputStream is = TrendingMain.class.getResourceAsStream(script)) { return engine.eval(new InputStreamReader(is, "utf-8")); } } } To initialize Nashorn, we use JSR-223's javax.script. private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); This code sets up an instance of the Nashorn engine for evaluating scripts. The load method reads a script into memory and then gets engine to eval that script. Note, that load also returns the result of the eval. Now for the fun part. There are several different approaches we could use to communicate between the Java main and the script. In this example we'll use a Java interface. The JavaFX main needs to do at least start and stop, so the following will suffice as an interface; public interface Trending { public void start(Stage stage) throws Exception; public void stop() throws Exception; } At the end of the example's script we add; (function newTrending() { return new Packages.Trending() { start: function(stage) { var data = getTrendingData(); graph(stage, data); stage.show(); }, stop: function() { } } })(); which instantiates a new subclass instance of Trending and overrides the start and stop methods. The result of this function call is what is returned to main via the eval. trending = (Trending) load("Trending.js"); To recap, the script Trending.js contains functions getTrendingData, graph and newTrending, plus the call at the end to newTrending. Back in the Java code, we cast the result of the eval (call to newTrending) to Trending, thus, we end up with an object that we can then use to call back into the script. trending.start(stage); Voila. ?

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Nashorn in the Twitterverse

- by jlaskey

I have been following how often Nashorn has been showing up on the net. Nashorn got a burst of tweets when we announced Project Nashorn and I was curious how Nashorn was trending per day, maybe graph the result. Counting tweets manually seemed mindless, so why not write a program to do the same. This is where Nashorn + Java came shining through. There is a very nice Java library out there called Twitter4J https://github.com/yusuke/twitter4j that handles all things Twitter. After running bin/getAccessToken.sh to get a twitter4j.properties file with personal authorization, all I had to do to run my simple exploratory app was; nashorn -cp $TWITTER4J/twitter4j-core-3.0.1.jar GetHomeTimeline.js The content of GetHomeTimeline.js is as follows; var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.count = 100; do { var result = twitter.search(query); var tweets = result.tweets; for each (tweet in tweets) { print("@" + tweet.user.screenName + "\t" + tweet.text); } } while (query = result.nextQuery()); How easy was that? Now to hook it up to the JavaFX graphing library...

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OpenJDK ? Nashorn ?????????

- by Homma

???? Nashorn ? OpenJDK ??????????????????Nashorn ? OpenJDK ????????????????????????????????????????????????????????????????????????????????? ????? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/the_vote_is_in ???????? ?? ?????????????????????????????? Jim Laskey ???????????? Nashorn ??????????? [1] ? ????????? ??: 20 ??: 0 ??: 0 ??????????????????????????????? ????????????????????????????????? -John Coomes [1] http://mail.openjdk.java.net/pipermail/announce/2012-November/000139.html

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Twitter ?? Nashorn ????

- by Homma

????? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/nashorninthe_twitterverse ???????? ?? Nashorn ?????????????????????????????????Project Nashorn ???????????Nashorn ?????????????????????Nashorn ???????????????????????????????????????????????????????????????????????????????????????????????????????? ??????? Nashorn + Java ???????????????????Java ?? Twitter4J https://github.com/yusuke/twitter4j ?????????????????Twitter ?????????????????bin/getAccessToken.sh ?????twitter4j.properties ????????????????????????????????? nashorn -cp $TWITTER4J/twitter4j-core-3.0.1.jar GetHomeTimeline.js GetHomeTimeline.js ????????? var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.count = 100; do { var result = twitter.search(query); var tweets = result.tweets; for each (tweet in tweets) { print("@" + tweet.user.screenName + "\t" + tweet.text); } } while (query = result.nextQuery()); ?????????????? JavaFX ???????????????????????...

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Welcome To The Nashorn Blog

- by Homma

??? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/welcome_to_the_nashorn_blog ???????? ?? ??????????????Nashorn ????????????????????????????????????????????????????????????????????????????? Nashorn ?????????????????????????????????????????????????????? ????? JavaOne ??????????Nashorn ???????????????????????????????? Georges Saab ????????????????????????????????????????????????????????????????? JavaOne ????????????????????????????????? ?Nashorn: JVM ??? JavaScript ????????????? ?????????(????????)??????????????????????????????????????????????????JVM ???????????????????????????????????????????????????????????????? ?Nashorn: JVM ?? JavaScript? ??? Nashorn ???????????????????????????????????????????????????Nashorn ???????????????????????????250 ??????????????????????????Twitter ? Sam Pullara ??? Mustache.js ???????(Rhino ? 20 ?????)???????????NetBeans ? John Ceccarelli ??? Nashorn ? Netbeans ??????????????????????????????? Q & A ???????????????? ?Nashorn JavaScript Team ???? Michel ? Attila ? Marcus ??? Q & A ??????????????(??????????????????????????)?????????? Node.jar ??????????Nashorn + Node.jar ???????????????????????????????? Node.jar ? Akhil ??????????????????? ?Nashorn ? Node ? Java Persistence? Doug Clarke ? Akhil ?????????????????(????????? ???????)?????? Q & A ??????????? 80 ??????? ?????? Node.jar ????????Doug ? Nashorn + JPA ??????? ?????????????Nashorn ????????????????? ????????????????? : Nashorn ? Java ???????? Attila ??????? Dynalink ? Nashorn ??????????????????????????????????????????????????????JVM ???????????????????????????????????? ????JavaOne ?? Java ??????????? JVM ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ????????? Nashorn ???? how to ?????????????????????????????????????????????? ??????????!

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Twitter ?? Nashorn ????(??)

- by Homma

???? Nashorn ? Java ??????? Twitter ???????????????????? JavaFX ??????????????? ????? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/nashorn_in_the_twitterverse_continued ???????? ?? Twitter ???????????????????????? JavaFX ??????????????????????????????? Nashorn ?? JavaFX ??????????????JavaFX ???????????????????????????????????????Nashorn ? Java ????????????????????????????????????(JavaFX ?????????????????????)? ?????????????????????????????????????????????? Twitter ????????????????????????? var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; function getTrendingData() { var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.since("2012-11-21"); query.count = 100; var data = {}; do { var result = twitter.search(query); var tweets = result.tweets; for each (var tweet in tweets) { var date = tweet.createdAt; var key = (1900 + date.year) + "/" + (1 + date.month) + "/" + date.date; data[key] = (data[key] || 0) + 1; } } while (query = result.nextQuery()); return data; } ??????????????????getTrendingData() ??????????????(??????????Nashorn ???????? OpenJDK ?????? 2012 ? 11 ? 21 ???)??????????????????????????????????? ????JavaFX ? BarChart ??????????? var javafx = Packages.javafx; var Stage = javafx.stage.Stage var Scene = javafx.scene.Scene; var Group = javafx.scene.Group; var Chart = javafx.scene.chart.Chart; var FXCollections = javafx.collections.FXCollections; var ObservableList = javafx.collections.ObservableList; var CategoryAxis = javafx.scene.chart.CategoryAxis; var NumberAxis = javafx.scene.chart.NumberAxis; var BarChart = javafx.scene.chart.BarChart; var XYChart = javafx.scene.chart.XYChart; var Series = javafx.scene.chart.XYChart.Series; var Data = javafx.scene.chart.XYChart.Data; function graph(stage, data) { var root = new Group(); stage.scene = new Scene(root); var dates = Object.keys(data); var xAxis = new CategoryAxis(); xAxis.categories = FXCollections.observableArrayList(dates); var yAxis = new NumberAxis("Tweets", 0.0, 200.0, 50.0); var series = FXCollections.observableArrayList(); for (var date in data) { series.add(new Data(date, data[date])); } var tweets = new Series("Tweets", series); var barChartData = FXCollections.observableArrayList(tweets); var chart = new BarChart(xAxis, yAxis, barChartData, 25.0); root.children.add(chart); } ????????????????????????????????stage.scene = new Scene(root) ? stage.setScene(new Scene(root)) ????????????????????Nashorn ? stage ??????? scene ???????????????????(Dynalink ?????????)Java Beans ???????????????? (setScene()) ???????????????????????????????Nashorn ? FXCollections ??????????????????????????????observableArrayList(dates) ??????????Nashorn ? JavaScript ??? (dates) ? Java ???????????????????????????? JavaScript ?????????????????? Java ????????????????????????????????????????????????????????????? ????????????????????????????????? JavaFX ???????????????????????? JavaFX ??????????????javafx.application.Application ??????????????????????????? JavaFX ????????????????????????????????????????????????? import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import javafx.application.Application; import javafx.stage.Stage; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; public class TrendingMain extends Application { private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); private Trending trending; public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) throws Exception { trending = (Trending) load("Trending.js"); trending.start(stage); } @Override public void stop() throws Exception { trending.stop(); } private Object load(String script) throws IOException, ScriptException { try (final InputStream is = TrendingMain.class.getResourceAsStream(script)) { return engine.eval(new InputStreamReader(is, "utf-8")); } } } ???? Nashorn ??????? JSR-223 ? javax.script ????????? private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); ????????? JavaScript ???????? Nashorn ???????????????????? load ???????????????????????engine ???????????????load ????????????? ???????????????Java ???????????????????????????????????????????????????? Java ????????????????JavaFX ???????? start ????? stop ?????????????????????????????????????? public interface Trending { public void start(Stage stage) throws Exception; public void stop() throws Exception; } ?????????????????????????????? function newTrending() { return new Packages.Trending() { start: function(stage) { var data = getTrendingData(); graph(stage, data); stage.show(); }, stop: function() { } } } newTrending(); ?????? Trending ?????????????????????start ????? stop ??????????????????????????????????? eval ???? Java ??????????????? trending = (Trending) load("Trending.js"); ????????????????Trending.js ??????? getTrendingData ???????????? newTrending ????????????????????? Java ?????????newTrending ????????? eval ????????? Trending ????????????????????????????????????????????????????????? trending.start(stage); ???????? ???? Nashorn ????????? http://www.myexpospace.com/JavaOne2012/SessionFiles/CON5251_PDF_5251_0001.pdf ???????? Dynalink ??????? https://github.com/szegedi/dynalink ????????

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