Companion object is not accessiable from Java code?-CodePudding

As we know Kotlin and Java are inter-operable. When I try to access Java static variable inside Kotlin code it works, but when I try to access companion object in Java it does not work.

CodePudding user response：

There are no statics in Kotlin per se.

Properties of the companion object can be accessed in Java by explicitly referring to the Companion instance:

class MyKotlinClass {
    companion object {
        val someProperty = 42
    }
}

From Java:

int someProperty = MyKotlinClass.Companion.getSomeProperty();

You can also force Kotlin to output bytecode with static members (for Java) by using a JVM-specific annotation:

class MyKotlinClass {
    companion object {
        @JvmStatic
        val someProperty = 42
    }
}

From Java:

int someProperty = MyKotlinClass.getSomeProperty();

CodePudding user response：

You need to specify Companion explicitly. Java:

    MyFragment newFragment = MyFragment.Companion.newInstance();

That's because companion's methods are NOT static. The companion is static, but its methods are regular, instance methods.

CodePudding user response：

you just need to add JvmStatic annotation

companion object{
    @JvmStatic
    val x=10
}