java - 空指针访问: The variable arrayLocations can only be null at this location

Question

所以我试图读入一个文件并从中获取部分内容，但我在第 行不断收到上述错误

arrayLocations[i] = new Location(Double.parseDouble(xArray[1]), Double.parseDouble(xArray[2]))

    int total;
    BufferedReader bfr;
    String lineObtained = null;
    Location[] arrayLocations = null;

    try {

        bfr = Files.newBufferedReader(path);
        lineObtained = bfr.readLine();

    } catch (IOException e) {

        e.printStackTrace();
        return null;
    }

    String split = lineObtained.split("POSTAL_OFFICE")[1];
    String[] y = split.split(" ");
    double xCoord = Double.parseDouble(y[0].trim());
    double yCoord = Double.parseDouble(y[1].trim());
    Location postOffice = new Location(xCoord, yCoord);

    String split1 = lineObtained.split("WORKER_ADDRESS")[1];
    String[] y1 = split.split(" ");
    double xCoord1 = Double.parseDouble(y1[0].trim());
    double yCoord1 = Double.parseDouble(y1[1].trim());
    Location home = new Location(xCoord, yCoord);        

    split = lineObtained.split("POSTAL_ADDRESSES")[1].trim();
    String[] splits = split.split("\\r?\\n");

    for(int i = 0; i < splits.length; i++) {
        String[] xArray = splits[i].split(" ");
        arrayLocations[i] = new Location(Double.parseDouble(xArray[1]), Double.parseDouble(xArray[2]));
    }

    PWPInstance instance = new PWPInstance(total, arrayLocations, postOffice, home, random);
    return instance;

Answer 1

您将 arrayLocation 声明为 null 并且从未初始化它。

你可能想要类似的东西

Location[] arrayLocations = new Location[splits.length];

就在循环之前(无需在方法开头声明它，需要时声明它)，因为这是您首先使用它的地方，也是您知道数组需要有多大的地方。