为什么此语法在使用 nashorn 创建 Java 字符串数组时不起作用

Question

我看到了 New Java Array of Strings in Nashorn，并找到了解决方案。

但我只是想知道为什么我的原始代码会抛出异常：

var JStringArray = Java.type("java.lang.String[]");
var validExtensions = new JStringArray(".java", ".class", ".jar", ".xml");

例外是

Exception in thread "main" javax.script.ScriptException: TypeError: Can not create new object with constructor [Ljava.lang.String; with the passed arguments; they do not match any of its method signatures. in ~/scriptMonkey/js/samples/FileStatistics.js at line number 9
    at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:470)
    at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:454)
    at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:406)
    at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:402)
    at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:155)
    at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
    at Debugger.main(Debugger.java:16)
Caused by: ~/scriptMonkey/js/samples/FileStatistics.js:9 TypeError: Can not create new object with constructor [Ljava.lang.String; with the passed arguments; they do not match any of its method signatures.
    at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:57)
    at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:213)
    at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:185)
    at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:172)
    at jdk.nashorn.internal.runtime.linker.NashornStaticClassLinker.checkNullConstructor(NashornStaticClassLinker.java:108)
    at jdk.nashorn.internal.runtime.linker.NashornStaticClassLinker.getGuardedInvocation(NashornStaticClassLinker.java:96)
    at jdk.internal.dynalink.support.CompositeTypeBasedGuardingDynamicLinker.getGuardedInvocation(CompositeTypeBasedGuardingDynamicLinker.java:176)
    at jdk.internal.dynalink.support.CompositeGuardingDynamicLinker.getGuardedInvocation(CompositeGuardingDynamicLinker.java:124)
    at jdk.internal.dynalink.support.LinkerServicesImpl.getGuardedInvocation(LinkerServicesImpl.java:154)
    at jdk.internal.dynalink.DynamicLinker.relink(DynamicLinker.java:253)
    at jdk.nashorn.internal.scripts.Script$FileStatistics.:program(~/scriptMonkey/js/samples/FileStatistics.js:9)
    at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:637)
    at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
    at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
    at jdk.nashorn.internal.runtime.Context.evaluateSource(Context.java:1222)
    at jdk.nashorn.internal.runtime.Context.load(Context.java:839)
    at jdk.nashorn.internal.objects.Global.load(Global.java:1545)
    at jdk.nashorn.internal.scripts.Script$\^eval\_.:program(<eval>:1)
    at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:637)
    at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
    at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
    at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:449)
    ... 5 more

Answer 1

对于 JStringArray 构造函数，您只能传递数组元素的数量。

var JStringArray = Java.type("java.lang.String[]");
var validExtensions = new JStringArray(4);
validExtensions[0] = ".java";
...

所有 Java 数组类型对象都是接受单个参数的构造函数，即数组的 "length"。

为什么此语法在使用 nashorn 创建 Java 字符串数组时不起作用

Why is this syntax not working in creating Java String array with nashorn

java

nashorn