Question

我被Java中的类型完全殴打。

我在txt文件中有坐标，最终我要格式化为这些坐标的数组，每个数组项都是双精度。

我的txt文件的每一行都是这样的：

13.716              , 6.576600074768066

目前，我试图将这一行拆分为两个字符串的数组，然后我将尝试解析为双打，但我一直在标题中得到错误。我哪里错了？

将我的字符串Arraylist转换为格式化的双坐标列表的任何其他更好的方法都会很棒，就像这样

[[0,1], [0,2], 0,4]

代码：

 public static String[] getFileContents(String path) throws FileNotFoundException, IOException
    {
        InputStream in = new FileInputStream(new File(path));
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        List<String> data = new ArrayList<String>();
        StringBuilder out = new StringBuilder();
        String line;
//        Skips 1376 characters before accessing data
        reader.skip(1378);
        while ((line = reader.readLine()) != null) {            
                data.add(line);
//                System.out.println(line);
        }  

        for (int i=0; i < data.size(); i++){
            data.set(i, data.get(i).split(","));
        }
//        String[] dataArr = data.toArray(new String[data.size()]);
//        Test that dataArr[0] is correct
//        System.out.println(data.size()); 
//        List<String> formattedData = new ArrayList<String>();
//        for (int i = 0; i < data.size(); i++){
//            formattedData.add(dataArr[i].split(","));
//        }
        reader.close(); 
        return dataArr;
    }

Answer 1

split(",")方法返回字符串string[]的数组，并且不能通过字符串数组设置字符串。

包含let lan double variabels的Crate点类，然后创建此点的数组，并用读取每一行的数据填充它们：

class Point{
    double lat;
    double len;
    Point(double lat, double len){
        this.lat = lat;
        this.len = len;
    }
}

然后在代码中使用此类：

 public static String[] getFileContents(String path) throws FileNotFoundException, IOException
    {
        InputStream in = new FileInputStream(new File(path));
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        List<String> data = new ArrayList<String>();
        StringBuilder out = new StringBuilder();
        String line;
//        Skips 1376 characters before accessing data
        reader.skip(1378);
        while ((line = reader.readLine()) != null) {            
                data.add(line);
//                System.out.println(line);
        }  
        List<Point> points = new ArrayList<Point>();
        for (int i=0; i < data.size(); i++){
            double lat =  Double.parseDouble(data.get(i).split(",")[0]);

            double len =  Double.parseDouble(data.get(i).split(",")[1]);
            points.add(new Point(lat, len));
            //data.set(i, data.get(i).split(","));
        }
//        String[] dataArr = data.toArray(new String[data.size()]);
//        Test that dataArr[0] is correct
//        System.out.println(data.size()); 
//        List<String> formattedData = new ArrayList<String>();
//        for (int i = 0; i < data.size(); i++){
//            formattedData.add(dataArr[i].split(","));
//        }
        reader.close(); 
        return dataArr;
    }

Answer 2

你可以像这样更新你的while循环

while ((line = reader.readLine()) != null) {
    String[] splits = line.split(",");
    for(String s : splits) {
        data.add(s);
    }
}

不兼容的类型：String []无法转换为字符串

2 个答案: