Question

对于你们许多人来说，这是一个简单的问题，但我仍然无法在一段时间后解决它。我想读下面的文本文件，并执行排序并显示出来。

部分“HELP”应该是学生的显示乐队，但经过多次尝试我无法生成。

public class gradesorting {


    public static void main(String[] args) throws IOException {

         BufferedReader reader = new BufferedReader(new FileReader("grades.txt"));   

         List<String> grades = new ArrayList<String>();
         List<String> banding = new ArrayList<String>();
         List<String> student = new ArrayList<String>();
         String line;


            while ((line = reader.readLine()) != null)
              {
                 String[] lines = line.split(":");

             if (lines[0].equals("Student"))
             {
                    Pattern p = Pattern.compile("(?:([^:]*):(\\d*):)");
                    Matcher m = p.matcher(line);

                    while(m.find()) {

                            int i=1;    
                            String name = m.group(i);
                            int grade = new Integer(m.group(i+1));

                             System.out.println("Student with Grade "+ "HELP" + " and Band " + grade + " are," +name);


                    }
             }

             if (lines[0].equals("Band"))
             {
                    Pattern p = Pattern.compile("(?:([^:]*):(\\d*):)");
                    Matcher m = p.matcher(line);

                    while(m.find()) {

                            int i=1;    
                            String grade = m.group(i);
                            int band = new Integer(m.group(i+1));



                             System.out.println("Grade "+ grade + " equal Band " + band);





                    }
             }

             grades.add(line);
             banding.add(line);
             student.add(line);
          }

          reader.close();

}
}

读入文本文件

(this is only part of the text file)
there will be more lines of students)

Grade:1:2:3:4:5:
Band:D:1:A:2:B:3:C:4:
Student:Fiona:2:Cindy:1:Alyssa:4:
Student:Wendy:4:

我在控制台中的当前输出..

Grade D equal Band 1
Grade A equal Band 2
Grade B equal Band 3
Grade C equal Band 4
Student with Grade HELP and Band 2 are,Fiona
Student with Grade HELP and Band 1 are,Cindy
Student with Grade HELP and Band 4 are,Wendy

理想输出

Grade D equal Band 1
Grade A equal Band 2
Grade B equal Band 3
Grade C equal Band 4
Student with Grade D and Band 1 are, Cindy
Student with Grade A and Band 2 are, Fiona
Student with Grade C and Band 4 are, Wendy
Student with Grade C and Band 4 are, Alyssa

Answer 1

您必须在年级和乐队之间在java中建立连接。我使用了hashMap。

public static void main(String[] args) throws IOException {

     BufferedReader reader = new BufferedReader(new FileReader("grades.txt"));   

     HashMap<Integer, String> map = new HashMap<Integer,String>();

     List<String> grades = new ArrayList<String>();
     List<Integer> banding = new ArrayList<Integer>();
     String line;


        while ((line = reader.readLine()) != null)
          {
             String[] lines = line.split(":");

         if (lines[0].equals("Student"))
         {
                Pattern p = Pattern.compile("(?:([^:]*):(\\d*):)");
                Matcher m = p.matcher(line);

                while(m.find()) {

                        int i=1;    
                        String name = m.group(i);
                        int grade = new Integer(m.group(i+1));



                         System.out.println("Student with Grade "+ map.get(grade) + " and Band " + 
                         grade + " are," +name);


                }
         }

         if (lines[0].equals("Band"))
         {
                Pattern p = Pattern.compile("(?:([^:]*):(\\d*):)");
                Matcher m = p.matcher(line);

                while(m.find()) {

                        int i=1;    
                        String grade = m.group(i);
                        int band = new Integer(m.group(i+1));



                         System.out.println("Grade "+ grade + " equal Band " + band);

                         map.put(band, grade);



                }
         }



      }

      reader.close();}}

Array List仅读取多个条目并显示

1 个答案: