ArrayList中到对象[] [] [英] ArrayList to Object[][]

问题描述

我需要转换一个数组列表为Object [] []，我曾尝试几种不同的方法，并且似乎都折腾了一个或两个错误。

I need to convert an Array List to Object[][], I have tried several different methods, and all seem to toss up an error or two.

我最新的尝试是这样的：

My latest try is this:

Object[][] array = dataList.toArray(new Object[dataList.size()][]);

这引发以下错误：

java.lang.ArrayStoreException
    at java.lang.System.arraycopy(Native Method)
    at java.util.ArrayList.toArray(Unknown Source)

我的数组列表中填充了我做了班，这是类：

My array list is populated with classes I made, this is the class:

class dataClass {
    int x;
    int y;
    int z;
    String string1;
    String string2;
    Date date;
    int event;

    public dataClass(int x, int y, int z, String string1, String string2,
            Date date, int event) {
        this.x = x;
        this.y = y;
        this.z = z;
        this.string1 = string1;
        this.string2 = string2;
        this.date = date;
        this.event = event;
    }
}

这是我如何初始化我数组列表：

This is how I initialize my array list:

public static List<dataClass> dataList = new ArrayList<dataClass>();

我然后通过加入我的新数据类：

I then add my new dataClass via:

.add(new dataClass(...));

任何帮助将是巨大的，谢谢。

Any help would be great, thanks.

推荐答案

您的问题没有完全确定，但这里是我最好的猜测你想要的东西：

Your question is not completely specified, but here's my best guess for what you want:

Object[][] array = new Object[dataList.size()][];
int i = 0;
for (DataClass c : dataList)
{
    array[i] = new Object[7];
    array[i][0] = c.x;
    array[i][1] = c.y;
    array[i][2] = c.z;
    array[i][3] = c.string1;
    array[i][4] = c.string2;
    array[i][5] = c.date;
    array[i][6] = c.event;
    i++;
}

至于这是否是好的设计或没有，没有的你试图完成什么解释，我真的不能发表评论。这个做什么，我想你想，但底层设计会给我停下来。我会试着去了解的目的，然后在一个更Java的惯用方式书写。

As to whether this is good design or not, without an explanation of what you're trying to accomplish, I can't really comment. This does what I think you want, but the underlying design would give me pause. I would try to understand the objective and then write it in a more Java-idiomatic manner.

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