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我最近一直在玩Play！框架和Nashorn試圖呈現Redux應用程序。最初，我在一個ThreadPoolExecutor中實現了多個Nashorn引擎，並在運行engine.eval()時使用了期貨。性能非常糟糕，我認爲是由於I/O高和我使用的阻塞未來。試圖使納順線程安全
變得更加熟悉Play！和他們的異步/承諾模式，我試圖重新開始只有一個ScriptEngine;每https://stackoverflow.com/a/30159424/5956783，腳本引擎本身是線程安全的，但綁定不是。這是在整體上類：
package services;
import akka.actor.ActorSystem;
import play.libs.F;
import scala.concurrent.ExecutionContext;
import java.io.FileReader;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.script.*;
@Singleton
public class NashornEngine extends JSEngineAbstract {
private NashornThread engine;
private final ActorSystem actorSystem;
protected class NashornThread {
private ScriptEngine engine;
private final ExecutionContext executionContext = actorSystem.dispatchers().lookup("js-engine-executor");
private CompiledScript compiledScript;
public NashornThread() {
try {
String dir = System.getProperty("user.dir");
this.engine = new ScriptEngineManager(null).getEngineByName("nashorn");
this.compiledScript = ((Compilable) this.engine).compile(new FileReader(dir + "/public/javascripts/bundle.js"));
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
public ScriptEngine getEngine() {
return engine;
}
public F.Promise<String> getContent(String path, String globalCode) {
return F.Promise.promise(() -> this.executeMethod(path, globalCode), this.executionContext);
}
private String executeMethod(String path, String json) throws ScriptException {
Bindings newBinding = engine.createBindings();
try {
this.compiledScript.eval(newBinding);
getEngine().setBindings(newBinding, ScriptContext.ENGINE_SCOPE);
getEngine().eval("var global = this;");
getEngine().eval("var console = {log: print, error: print, warn: print};");
String result = getEngine().eval("App.renderApp('" + path + "', " + json + ")").toString();
return result;
} catch(Exception e) {
e.printStackTrace();
return null;
}
}
}
@Inject
public NashornEngine(ActorSystem actorSystem) {
this.actorSystem = actorSystem;
this.engine = new NashornThread();
}
@Override
public F.Promise<String> getContent(String path, String globalCode) {
try {
F.Promise<String> result = engine.getContent(path, globalCode);
return result.map((String r) -> r);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
我的JavaScript應用出口的App對象與方法renderApp(path, state)可見。這其實確實工作，但只有16倍（是的，總是16）。與迭代17日開始，我得到下面的異常，並伴隨堆棧跟蹤：
java.lang.ClassCastException: jdk.nashorn.internal.objects.NativeRegExpExecResult cannot be cast to jdk.nashorn.internal.objects.NativeArray
at jdk.nashorn.internal.objects.NativeArray.getContinuousArrayDataCCE(NativeArray.java:1900)
at jdk.nashorn.internal.objects.NativeArray.popObject(NativeArray.java:937)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:660)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:228)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.internal.scripts.Script$Recompilation$23589$782286AA$\^eval\_.L:22918$L:22920$matchPattern(<eval>:23049)
at jdk.nashorn.internal.scripts.Script$Recompilation$23588$816752AAAAAA$\^eval\_.L:24077$L:24079$matchRouteDeep(<eval>:24168)
at jdk.nashorn.internal.scripts.Script$Recompilation$23587$820262DAA$\^eval\_.L:24077$L:24079$matchRoutes$L:24252$L:24253(<eval>:24254)
at jdk.nashorn.internal.scripts.Script$Recompilation$23586$809060$\^eval\_.L:23848$loopAsync$next(<eval>:23869)
at jdk.nashorn.internal.scripts.Script$Recompilation$23584$808906AAA$\^eval\_.L:23848$loopAsync(<eval>:23875)
at jdk.nashorn.internal.scripts.Script$Recompilation$23583$820189$\^eval\_.L:24077$L:24079$matchRoutes$L:24252(<eval>:24253)
at jdk.nashorn.internal.scripts.Script$Recompilation$23582$819862AAA$\^eval\_.L:24077$L:24079$matchRoutes(<eval>:24252)
at jdk.nashorn.internal.scripts.Script$Recompilation$23580$789440AA$\^eval\_.L:23151$L:23153$useRoutes$L:23209$match(<eval>:23239)
at jdk.nashorn.internal.scripts.Script$Recompilation$23518$847004AA$\^eval\_.L:25026$L:25028$match(<eval>:25084)
at jdk.nashorn.internal.scripts.Script$Recompilation$23468$3872AA$\^eval\_.L:53$renderApp(<eval>:147)
at jdk.nashorn.internal.scripts.Script$23467$\^eval\_.:program(<eval>:1)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:640)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:228)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:446)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:403)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:399)
at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:155)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
at services.NashornEngine$NashornThread.executeMethod(NashornEngine.java:62)
at services.NashornEngine$NashornThread.lambda$getContent$0(NashornEngine.java:48)
at play.core.j.FPromiseHelper$$anonfun$promise$2.apply(FPromiseHelper.scala:36)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:397)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
我的印象是，創建與編輯腳本一個新的綁定將作爲淨新的發動機下處理，但沒有按似乎並非如此。如果有什麼，我在這裏做錯了什麼？
我試圖使用Invocable以調用App對象上的方法，但這沒有什麼區別。
編輯 我在一個具有超線程的8核心機器上，這樣可以解釋失敗的第17次嘗試之前的16次成功嘗試。另外，我已經更新了executeMethod方法如下：
private String executeMethod(String path, String json) throws ScriptException {
Bindings newBinding = engine.createBindings();
try {
this.compiledScript.eval(newBinding);
getEngine().eval("var global = this;", newBinding);
getEngine().eval("var console = {log: print, error: print, warn: print};", newBinding);
Object app = getEngine().eval("App", newBinding);
Invocable invEngine = (Invocable) getEngine();
String result = invEngine.invokeMethod(app, "renderApp", path, json).toString();
// String result = getEngine().eval("App.renderApp('" + path + "', " + json + ")", newBinding).toString();
return result;
} catch(Exception e) {
e.printStackTrace();
return null;
}
}
是的！它的工作完美。謝謝！ –