相关疑难解决方法(0)

我的程序使用Java Scripting API并且可以同时评估一些脚本.他们不使用共享脚本对象,绑定或上下文,但可以使用相同ScriptEngine和CompiledScript对象.我看到Java 8中的Oracle Nashorn实现不是多线程的,ScriptEngineFactory.getParameter('THREADING')返回null文档所说的内容:

引擎实现不是线程安全的,不能用于在多个线程上并发执行脚本.

这是否意味着我应该ScriptEngine为每个线程创建一个单独的实例？此外,文档没有说明CompiledScript并发使用,但:

每个CompiledScript都与ScriptEngine相关联

可以假设CompiledScript线程安全依赖于相关ScriptEngine,即我应该CompiledScript为Nashorn的每个线程使用单独的实例.

如果我应该,对于这个(我认为非常常见的)案例,使用ThreadLocal,池或其他什么是适当的解决方案？

final String script = "...";
final CompiledScript compiled = ((Compilable)scriptEngine).compile(script);
for (int i=0; i<50; i++) {
    Thread thread = new Thread () {
        public void run() {
            try {
                scriptEngine.eval(script, new SimpleBindings ());  //is this code thread-safe?
                compiled.eval(new SimpleBindings ());  //and this?
            }
            catch (Exception e)  {  throw new RuntimeException …

如果函数不更改任何共享对象但仅使用给定的参数,是否可以重用同一个Nashorn引擎和同一个JavaScriptObject(对于所有servlet请求,作为JS函数的评估)电话？请看以下示例:

public class MyServlet extends HttpServlet {

private ScriptEngineManager factory;
private ScriptEngine engine;
private ScriptObjectMirror script;

@Override
public void init() throws ServletException {
    try {
        factory = new ScriptEngineManager();
        engine = factory.getEngineByName("nashorn");
        script = (ScriptObjectMirror)engine.eval("function(writer) {writer.print('Hello, World!');}");
    } catch (ScriptException ex) {
        Logger.getLogger(MyServlet.class.getName()).log(Level.SEVERE, null, ex);
    }
}

@Override
public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException {
    try (PrintWriter writer = res.getWriter()) {
        script.call(null, writer);
        writer.close();
    } catch (IOException ex) {
        Logger.getLogger(MyServlet.class.getName()).log(Level.SEVERE, null, ex);
    }
}

这是线程安全的吗？这是在Servlet中重用Nashorn ScriptEngine的后续内容 …

如果以下代码可以在多线程应用程序中运行,您能帮我解决吗？

这是我的Java脚本,将由Nashorn评估

var Thread = Java.type("java.lang.Thread");
var referenceNumberValid = "0000";
var referenceNumberInvalid = "0001";

function validate (parameters) {
    var isValid = false;
    var statusCode;
    var referenceNumber = parameters.referenceNumber;
    var validateNumber = referenceNumber.substr(0, 7);
    var sum = 0;

    for (ctr = 0; ctr < validateNumber.length; ctr++) {
        sum += parseInt(validateNumber.substr(ctr, 1));
    }

    var checkDigit = sum % 10;
    isValid = parseInt(referenceNumber.substr(7, 1)) == checkDigit;
    statusCode = isValid ? referenceNumberValid : referenceNumberInvalid;

    print("Thread: " + Thread.currentThread().getId() + ", isValid: " + isValid …