kotlin自定义从mutableList获取不可变列表 [英] kotlin custom get immutable list from mutableList

问题描述

我有一个用于可变列表的自定义getter方法，可以通过使用Google的Guava库返回一个固定的列表.然后在构造函数中访问此可变列表.

I have a custom getter method for a mutable list to return an immtuable list by using Google's Guava library. And then this mutable list is accessed in the constructor.

data class mutableClass(val list: List<Foo>) {

    private val mutableList: MutableList<Foo>
        get() = ImmutableList.copyOf(field)

    init {
       mutableList = mutableListOf()
       list.forEach {
          mutableList.add(it.copy()) // Exception is thrown here.
          // It actually calls its getter method which is an immutable 
          // list, so when init this class, it throw exception                   
       }
    }
}

data class Foo {}

然后我将其反编译为Java，在init块中，它调用mutableList的getter方法. 有没有一种方法可以调用mutabbleList本身而不是getter方法?

And I decompile it to Java, in the init block, it calls the getter method of mutableList. Is there a way to call the mutabbleList itself instead of getter method?

推荐答案

当然，它会调用getter(返回ImmutableList.copyOf(field)).

Of course it calls the getter (which returns ImmutableList.copyOf(field)).

您可以在init块中简单地分配给mutableList新复制的可变列表:

You can do simply assignment to mutableList new copied mutable list in your init block:

data class MutableClass(val list: List<Foo>) {

    private val mutableList: MutableList<Foo>
        get() = ImmutableList.copyOf(field)

    init {
        mutableList = list.map { it.copy() }.toMutableList()
    }
}

或没有init:

data class MutableClass(val list: List<Foo>) {

    private val mutableList: MutableList<Foo> = list.map { it.copy() }.toMutableList()
        get() = ImmutableList.copyOf(field)

}

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