我一直在努力解决使用java scripting API来控制某些用户定义的javascript的执行问题。我正在使用内置的Rhino引擎,它说你可以设置InstructionObserverThreshold,如果达到限制,它将负责停止执行。我一直在玩下面的示例应用程序一段时间,并且我为什么不起作用而难以接受。你会看到我已经设置了MaximumInterpreterStackDepth。这很好,但指导观察员似乎没有做任何事情。在javax.scripting环境中设置instructionObserverThreshold
有关此代码缺失的任何想法,使其工作?
谢谢!
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import com.sun.script.javascript.RhinoScriptEngine;
public class RhinoTester2 {
public static void main(String[] args) {
new RhinoScriptEngine(); // initialize the global context.
sun.org.mozilla.javascript.internal.ContextFactory cx = sun.org.mozilla.javascript.internal.ContextFactory.getGlobal();
cx.addListener(new sun.org.mozilla.javascript.internal.ContextFactory.Listener() {
public void contextCreated(sun.org.mozilla.javascript.internal.Context cxt) {
cxt.setInstructionObserverThreshold(10000); // This should stop after 10 seconds or so.
cxt.setMaximumInterpreterStackDepth(1); // this should not be a factor for the moment
System.out.println("Context Factory threshold set. "+cxt.getInstructionObserverThreshold());
}
@Override
public void contextReleased(
sun.org.mozilla.javascript.internal.Context arg0) {
System.out.println("Context Released.");
}
});
// Now run the script to see if it will be stopped after a short time.
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine engine = mgr.getEngineByName("javascript");
try {
// engine.eval("while(true){println(\"hello\");};"); // This will fail immediately due to the interpreter stack depth.
engine.eval("while(true){};"); // this never fails. runs happily forever.
} catch (ScriptException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
不幸的是,脚本API使用的基本ContextFactory中没有提供处理InstructionObservationCount的推荐方法。在查看RhinoScriptEngine时,用户无法修改ContextFactory以添加实现(密封类和匿名静态块调用initGlobal)。从我可以告诉你只有两个选项 - 要么创建自己的脚本引擎,并替换内置版本或在线程中管理它,并在超过超时时间后终止线程。令人失望的..... –