java - 创建学生文件，查看平均成绩高于5的学生信息以及每个学生的平均成绩

Question

//Create the file Alumns.txt where we have a group of students with their last names, names and average grade, separed by “,” and view the information from the students that have more average grade from 5 and the average grade from each student.

//We have the file Alumns.txt with the content:

//雷莫·拉米雷斯、诺埃利亚、6、希门尼斯·桑托斯、卡洛斯、4、佩雷斯·戈麦斯、费尔南多、7、汉密尔顿·布莱恩、泰勒、3、古铁雷斯·门多萨、何塞、8、加西亚·雷耶斯、玛丽亚、6、马尔坎特·门德斯、卢娜，3 岁，德尔加多·门德斯，安吉尔，10 岁。

public class Main {

    public static void main(String[] args) {


        File fichero = null;
        FileReader fr = null;
        Scanner sc = null;
        double [] notas = new double [6];

文件 Alumnos.txt

        fichero = new File ("Alumnos.txt");
        try {
            BufferedReader br = new BufferedReader(fr);
            String texto2 = br.readLine();
            fr = new FileReader(fichero);
            sc = new Scanner(fichero);
            String texto = sc.nextLine();
            StringTokenizer tokens = new StringTokenizer(texto2, ",");

//我尝试使用 Scanner 和 BufferedReader，“notas”(数字)各为 3 个标记。

            for (int i = 0; i < notas.length; i++) {
                tokens.nextToken();
                tokens.nextToken();
                notas[i] = (double)Double.parseDouble(tokens.nextToken());
                System.out.println("Nota: "+notas[i]);
                if (notas [i]>5) {
                    System.out.println("Pass the grade 5: "+tokens.nextToken());
                }
            }
//I catch the exceptions here:

        } catch (FileNotFoundException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }

    }

}

Answer 1

假设我们有这个文件grades.csv

Remo Ramirez,Noelia,6
Jimenez Santos,Carlos,4
Perez Gomez,Fernando,7
Hamilton Bryan,Taylor,3
Gutierrez Mendoza,Jose,8
Garcia Reyes,Maria,6
Marchante Mendez,Luna,3
Delgado Mendez,Angel,10

我们可以编写这个方法来解析它并仅打印平均成绩高于 5 的学生。

public static void printGradesBetterThanFive() throws IOException {

        //Create a file object, path to the file might differ in your case.
        File grades = new File("grades.csv");
        if (grades.isFile()) {

            //Create a BufferedReader, taking in a FileReader with our File as an argument
            BufferedReader csvReader = new BufferedReader(new FileReader(grades));

            //Parse through each line in the file until we reach the end of it
            String line;
            while ((line = csvReader.readLine()) != null) {

                //Create an array containing values from each line, separated by commas.
                String[] lineData = line.split(",");

                //If the last value (the grade) is more than 5, print it.
                if (Integer.parseInt(lineData[2]) > 5) {
                    System.out.println(Arrays.toString(lineData));
                }
            }
            csvReader.close();
        }
    }

您的问题有点模糊，但希望这对您有所帮助。