javascript - Java Nashorn 实例方法

Question

我想尝试一下 Nashorn 脚本功能。一切正常，我似乎能够从我的 .js 脚本中调用静态方法，如下所示:

var fun3 = function() {
    print("Another day!");
    var Go = Java.type('somePack.Go');
    var result = Go.fun1('John Doe');
    print("\n" + result);
}

在我的“Go”Java 类中:

public static String fun1(String name) {
    System.out.format("Hi there from Java, %s", name);
    return "greetings from java";
}

但我想做的是使 fun1 方法成为非静态方法，使其成为一个实例化方法。

   public String fun1(String name) {
        System.out.format("Hi there from Java, %s", name);
        return "greetings from java";
    }

在我的 script.js 中，我确实尝试过:

var Go = new Java.type('somePack.Go');

但是我得到了错误:

Caused by: <eval>:19 TypeError: function type() { [native code] } is not a constructor function

有没有一种简单的方法可以实现我所追求的目标？

谢谢

全栈:

    at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:470)
    at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:392)
    at jdk.nashorn.api.scripting.NashornScriptEngine.invokeFunction(NashornScriptEngine.java:190)
    at somePack.Go.go(Go.java:35)
    at somePack.Go.main(Go.java:16)
Caused by: <eval>:19 TypeError: function type() { [native code] } is not a constructor function
    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.ScriptFunctionData.getBestConstructor(ScriptFunctionData.java:244)
    at jdk.nashorn.internal.runtime.ScriptFunction.findNewMethod(ScriptFunction.java:758)
    at jdk.nashorn.internal.runtime.ScriptObject.lookup(ScriptObject.java:1827)
    at jdk.nashorn.internal.runtime.linker.NashornLinker.getGuardedInvocation(NashornLinker.java:104)
    at jdk.nashorn.internal.runtime.linker.NashornLinker.getGuardedInvocation(NashornLinker.java:98)
    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$Recompilation$2$384$\^eval\_.fun3(<eval>:19)
    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.ScriptObjectMirror.callMember(ScriptObjectMirror.java:199)
    at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:386)

Answer 1

你应该使用

var Go = Java.type('somePack.Go');
var goObject = new Go();