从许多数组中查找匹配数组的更简单的方法

Question

我有以下数组，可以保存许多蓝牙信标的MAC附件及其在建筑物中的位置：

private static final String[][] MAC_ADDRESSES_A_BLUETOOTH = {{"B09122F5D126", "210.105"}, {"B09122F5F26B", "136.121"}, {"B09122F5F619", "181.172"}};
...
private static final String[][] MAC_ADDRESSES_Q_BLUETOOTH = {{"B09122F5D124", "210.105"}, {"B09122F5F26Z", "136.121"}, {"B09122F5F61Q", "181.172"}};

然后，我在寻找基于当前三元组的匹配三元组：

private String[][] compareArrays(String[] beacon) {
        if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_A_BLUETOOTH))) {
            return MAC_ADDRESSES_A_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_B_BLUETOOTH))) {
            return MAC_ADDRESSES_B_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_C_BLUETOOTH))) {
            return MAC_ADDRESSES_C_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_D_BLUETOOTH))) {
            return MAC_ADDRESSES_D_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_F_BLUETOOTH))) {
            return MAC_ADDRESSES_F_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_G_BLUETOOTH))) {
            return MAC_ADDRESSES_G_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_H_BLUETOOTH))) {
            return MAC_ADDRESSES_H_BLUETOOTH;
        } else if (Arrays.equals(beacon, getFirstArray(MAC_ADDRESSES_I_BLUETOOTH))) {
            return MAC_ADDRESSES_I_BLUETOOTH;
        } ...
        } else {
            return null;
        }
}

这段代码看上去糟透了，让我心烦。是否有一种无需编写16条if语句的更简单的方法来做到这一点呢？getFirstArray从一个二维数组返回所有的第一个值。

Answer 1

为提高可读性，请使用对象而不是2d数组。

例如：

public class BluetoothMacAddress {
    private String macAddress;
    private float positionInBuilding;
}

使用java.util.List，您就可以得到一个列表：

private sttaic final List<MacAddress> MAC_ADDRESSES_A_BLUETOOTH = Arrays.asList(
    new BluetoothMacAddress("B09122F5D126", "210.105"),  
    new BluetoothMacAddress("B09122F5F26B", "136.121"), 
    new BluetoothMacAddress("B09122F5F619", "181.172"));

private static final List<List<MAC_ADDRESSES>> MAC_ADDRESSES = Arrays.asList(
    MAC_ADDRESSES_A_BLUETOOTH,
    MAC_ADDRESSES_B_BLUETOOTH 
    ...
);

然后，您的新方法将如下所示：

private MacAddress compareArrays(String[] beacon) {
    for (List<MacAddress> macAddresses : MAC_ADDRESSES ) {
        if (Arrays.equals(beacon, getFirstArray(macAddresses))) {
            return macAddresses;
        }
    }
    // not found
    return null;
}

您必须将beacon参数也更改为MacAddress，或者将MacAddress转换为String[] (或visa-相反)。