JSR223 Javascript 中的回调，Oracle JRE 1.6 和 OpenJDK 1.6 之间的差异（安装在 Debian 上）

发布于 2024-11-05 17:29:43 字数 1605 浏览 0 评论 0原文

鉴于以下情况，使用 Oracle JRE 6 运行会给出输出 boo，但 OpenJDK 6 会给出异常

javax.script.ScriptException: sun.org.mozilla.javascript.EvaluatorException: The choice of Java
constructor replace matching JavaScript argument types (function,string) is ambiguous; candidate 
constructors are: 
    class java.lang.String replace(char,char)
    class java.lang.String replace(java.lang.CharSequence,java.lang.CharSequence) (<Unknown source>#1) 
in <Unknown source> at line number 1

这可能是因为使用 OpenJDK（可能是随其提供的 rt.jar）该函数获取了 java.lang.String，但是对于 Oracle 来说，它会获取一个 JavaScript 字符串（或者可以隐式强制转换为一个的字符串）。

那么哪个更正确呢？ Javascript（在本例中）是 API，那么我们是否可以编写 Java，使得两种实现的 API 都相同？（如果 OpenJDK 实现“更正确”（因此很可能是将来每个人都会做的事情），那么我猜想更改 API（文档、示例、测试）并添加 new String(...)< /code> 适当的不是不可能的，但我宁愿不丑化 API，除非我更有信心。

import javax.script.*;

class st {
    public static void main(String[] args) {
        ScriptEngineManager mgr = new ScriptEngineManager();
        ScriptEngine jsEngine = mgr.getEngineByName("JavaScript");
        Bindings bindings = jsEngine.getBindings(ScriptContext.ENGINE_SCOPE);
        Foo foo = new Foo();
        bindings.put("v", foo);
        try {
            jsEngine.eval("v.run(function(a) {println(a.replace(/f/,\"b\"));})");
        } catch (ScriptException ex) {
            ex.printStackTrace();
        }    
    }
}

）

public class Foo {
    public void run(FooCB cb) {
        cb.run("foo");
    }
    public static interface FooCB {
        public void run(Object val);
    }
}

原文

Given the following, running with Oracle JRE 6 gives the output boo, but OpenJDK 6 gives an exception

javax.script.ScriptException: sun.org.mozilla.javascript.EvaluatorException: The choice of Java
constructor replace matching JavaScript argument types (function,string) is ambiguous; candidate 
constructors are: 
    class java.lang.String replace(char,char)
    class java.lang.String replace(java.lang.CharSequence,java.lang.CharSequence) (<Unknown source>#1) 
in <Unknown source> at line number 1

That's presumably because with OpenJDK (presumably the rt.jar supplied with it) the function's getting a java.lang.String, but with Oracle's it's getting a JavaScript String (or something that can be implicitly coerced to one).

So which is more correct? The Javascript (in this case) is the API, so can we write the Java such that the API's the same for either implementation? (If the OpenJDK implementation is "more correct" (and so likely to be what everyone does in the future), then I guess changing the API (documentation, examples, tests) throwing in new String(...) as appropriate wouldn't be impossible, but I'd rather not uglify the API unless I'm more confident.)

import javax.script.*;

class st {
    public static void main(String[] args) {
        ScriptEngineManager mgr = new ScriptEngineManager();
        ScriptEngine jsEngine = mgr.getEngineByName("JavaScript");
        Bindings bindings = jsEngine.getBindings(ScriptContext.ENGINE_SCOPE);
        Foo foo = new Foo();
        bindings.put("v", foo);
        try {
            jsEngine.eval("v.run(function(a) {println(a.replace(/f/,\"b\"));})");
        } catch (ScriptException ex) {
            ex.printStackTrace();
        }    
    }
}

and

public class Foo {
    public void run(FooCB cb) {
        cb.run("foo");
    }
    public static interface FooCB {
        public void run(Object val);
    }
}

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