我有一个在 java-8-openjdk-amd64 上运行的 java 应用程序,它评估 java 脚本。现在我安装了 GraalVM Community Edition graalvm-ce-19.2.0 (ubuntu 18.04) 并尝试使用 org.graalvm.polyglot.Context
评估一些 javascript 示例
它们是有效的,但当我发现旧的 java 脚本代码崩溃并且堆栈跟踪显示它是使用 org.graalvm 包而不是 javax.script 评估时,我感到很惊讶:
import javax.script.ScriptEngine;
...
ScriptEngine engine =
scriptFactory.getEngineByName("JavaScript");
engine.put("form", postedAnswer);
engine.put("question", jsQuestion);
engine.put("answer", jsAnswer);
engine.eval(validationJS); //here Exception thrown
此处堆栈跟踪:
javax.script.ScriptException: org.graalvm.polyglot.PolyglotException: TypeError: invokeMember (getData) on JavaObject[com.researchforgood.survey.surveyengine.JSQuestion@504641f2 (com.researchforgood.survey.surveyengine.JSQuestion)] failed due to: Unknown identifier: getData
at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:348)
at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:323)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
at com.researchforgood.survey.surveyengine.service.StepService.validateAnswers(StepService.java:233)
at com.researchforgood.survey.surveyengine.service.StepService.processAnswers(StepService.java:95)
at com.researchforgood.survey.surveyengine.HttpSurveyHandler.doPost(HttpSurveyHandler.java:160)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at com.researchforgood.api.apigateway.ServletHandler.handle(ServletHandler.java:62)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:205)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:220)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:502)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:364)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.graalvm.polyglot.PolyglotException: TypeError: invokeMember (getData) on JavaObject[com.researchforgood.survey.surveyengine.JSQuestion@504641f2 (com.researchforgood.survey.surveyengine.JSQuestion)] failed due to: Unknown identifier: getData
at <js>.:program(<eval>:6)
at org.graalvm.polyglot.Context.eval(Context.java:344)
at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:346)
... 25 more
这让我很困惑。我以前从未在 JVM 中看到过这种行为。是不是Graalvm虚拟机不兼容Java虚拟机?
我看到提到的 polyglot.js.nashorn-compat 属性使 polyglot 以与 Nashorn 相同的方式工作,但这并没有回答我的问题,因为我没有在崩溃的代码中使用 org.graalvm.polyglot。
最佳答案
GraalVM/JavaScript 是 GraalVM 中用来执行 JavaScript 代码的 JavaScript 引擎。它基于 org.graalvm.(polyglot),因此您可以在堆栈跟踪中看到这一点,通常无需担心。出于兼容性原因,GraalVM/JavaScript 提供了 javax.script 的实现,但这只是(首选)org.graalvm.polyglot.Context 的包装器,用于与此类引擎交互。
您看到的具体错误可能是由于您的脚本试图访问默认情况下受 GraalVM 沙箱限制的资源。您需要传递额外的参数以允许此类访问,例如:
//create engine as in your example, then:
Bindings bindings = engine.getBindings(ScriptContext.ENGINE_SCOPE);
bindings.put("polyglot.js.allowAllAccess", true);
engine.eval(validationJS);
再次注意,这可能会增加您的安全攻击面,只能以这种方式执行受信任的代码(通常使用 ScriptEngine)!
有关更多选项以及如何使用 ScriptEngine 与 GraalVM/JavaScript 交互,请参阅 https://github.com/graalvm/graaljs/blob/master/docs/user/ScriptEngine.md
希望对您有所帮助, 基督徒
关于java - 为什么在 GraalVM 社区版上使用 org.graalvm.polyglot 而不是 javax.script 包?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57756143/