Java将每一行读入单独的数组

Question

我在一个文本文件中有 1,000 行数据，我希望每一行都是它自己的浮点数 []。

1,1,1,1,1,1
2,2,2,2,2,2
3,3,3,3,3,3

会导致：

 float[0] = {1,1,1,1,1,1}
 float[1] = {2,2,2,2,2,2}
 float[2] = {3,3,3,3,3,3}

这可能吗？ 我只能找到将整个文件加载到数组中的示例。 我尝试对所有数组进行硬编码，但超出了 ~65,000 的字节字符限制

Answer 1

请尝试以下操作：

// this list will store all the created arrays
List<float[]> arrays = new ArrayList<float[]>();

// use a BufferedReader to get the handy readLine() function
BufferedReader reader = new BufferedReader(new FileReader("myfile.txt"));

// this reads in all the lines. If you only want the first thousand, just
// replace these loop conditions with a regular counter variable
for (String line = reader.readLine(); line != null; line = reader.readLine()) {
    String[] floatStrings = line.split(",");
    float[] floats = new float[floatStrings.length];
    for (int i = 0; i < floats.length; ++i) {
        floats[i] = Float.parseFloat(floatStrings[i]);
    }
    arrays.add(floats);
}

请注意，我没有添加任何异常处理（例如，readLine() 抛出 IOException）。

Answer 2

使用LineIterator读取每一行而不加载整个文件
and iterator over the matches found with methods like and 对于每一行，使用正则表达式提取像并在使用和等方法的匹配项上进行迭代

Answer 3

 <body> <pre> package FirstPrac; import java.io.FileReader; public class Check { public static void main(String[] args) { readingfile(); } public static void readingfile() { try { FileReader read = new FileReader("D:\\\\JavaWkspace\\\\numbers.txt"); int index; String nums1 = ""; while ((index = read.read()) != -1) { if (((char) index) != '\\n') { nums1 += String.valueOf((char) index); } } System.out.println("Problem statement: Print out the greatest number on each line:\\n" + nums1); String f = nums1.substring(0, 14); String s = nums1.substring(15, 29); String t = nums1.substring(30); String[] fs = f.split(","); int size = fs.length; int[] arr = new int[size]; for (int i = 0; i < size; i++) { arr[i] = Integer.parseInt(fs[i]); } int max = arr[0]; for (int i = 0; i < arr.length; i++) { if (max < arr[i]) { max = arr[i]; } } System.out.println("\\nGreatest number in the first line is:" + (max)); String[] sstr = s.split(","); int size2 = sstr.length; int[] arr2 = new int[size2]; for (int i = 0; i < size2; i++) { arr2[i] = Integer.parseInt(sstr[i]); } int max2 = arr2[0]; for (int i = 0; i < arr2.length; i++) { if (max2 < arr2[i]) { max2 = arr2[i]; } } System.out.println("\\nGreatest number in the second line is:" + (max2)); String[] str3 = t.split(","); int size3 = str3.length; int[] arr3 = new int[size3]; for (int i = 0; i < size3; i++) { arr3[i] = Integer.parseInt(str3[i]); } int max3 = arr3[0]; for (int i = 0; i < arr3.length; i++) { if (max3 < arr3[i]) { max3 = arr3[i]; } } System.out.println("\\nGreatest number in the third line is:" + (max3)); read.close(); } catch (Exception e) { System.out.println(e); } } } </pre> </body>

Answer 4

使用 .split("\\n") 循环遍历文件的行分隔内容，然后将每个结果转换为浮点数组。 这是将字符串转换为浮点数的方法 => http://www.devdaily.com/java/edu/qanda/pjqa00013.shtml

Java将每一行读入单独的数组

问题描述

4 个解决方案

解决方案1
3 2012-09-21 02:55:44

解决方案2
0 2012-09-21 02:43:19

解决方案3
0 2021-11-22 08:23:44

解决方案4
-1 2012-09-21 02:36:18

Java将每一行读入单独的数组

问题描述

4 个解决方案

解决方案1 3 2012-09-21 02:55:44

解决方案2 0 2012-09-21 02:43:19

解决方案3 0 2021-11-22 08:23:44

解决方案4 -1 2012-09-21 02:36:18

解决方案1
3 2012-09-21 02:55:44

解决方案2
0 2012-09-21 02:43:19

解决方案3
0 2021-11-22 08:23:44

解决方案4
-1 2012-09-21 02:36:18