为什么我的列表中的所有元素似乎都是相同的？

我有以下代码：

Integer[] lastExchange = new Integer[nColors];
Integer[] newExchange = new Integer[nColors];
while (true) {
    ...
    for (int i=0; i<nColors; i++) {
       lastExchange[i] = newExchange[i];
    }
    ...
    exchanges.add(lastExchange);
    output.log.fine("Exchange:" + lastExchange[0] + "," + lastExchange[1]);
}
for (Integer[] exchange : exchanges) {
    output.log.fine("Exchange:" + exchange[0] + "," + exchange[1]);
}

我有两个输出（一个在 while 循环中，另一个在 for 循环中）。第一个输出显示我确实向列表中添加了不同的数组。当我在第二个循环中进行双重检查时，我看到exchange列表是相同的（它们等于列表的第一个元素）。

有人知道我在这里做错了什么吗？

正如 unwind 的答案所述，您在循环的每次迭代中添加对同一数组的引用。你需要创建一个new每次数组：

// It's not clear where newExchange is actually populated
Integer[] newExchange = new Integer[nColors];
while (true) {
    Integer[] lastExchange = new Integer[nColors];
    ...
    for (int i=0; i<nColors; i++) {
       lastExchange[i] = newExchange[i];
    }
    ...
    exchanges.add(lastExchange);
    output.log.fine("Exchange:" + lastExchange[0] + "," + lastExchange[1]);
}

或者，如果您只是克隆数组：

Integer[] newExchange = new Integer[nColors];
while (true) {
    Integer[] lastExchange = newExchange.clone();
    ...
    exchanges.add(lastExchange);
    output.log.fine("Exchange:" + lastExchange[0] + "," + lastExchange[1]);
}