Question

I have a text file in my computer which I am reading form my java program, I want to build some criteria. Here is my Notepad File :

   #Students
   #studentId   studentkey  yearLevel   studentName token   
   358314           432731243   12          Adrian      Afg56       
   358297           432730131   12          Armstrong   YUY89       
   358341           432737489   12          Atkins      JK671   

        #Teachers
        #teacherId  teacherkey    yearLevel teacherName token   
        358314          432731243   12          Adrian      N7ACD       
        358297          432730131   12          Armstrong   EY2C        
        358341          432737489   12          Atkins      F4NGH

when I read from this note pad file, I get the exact data as it is in my application but I want to read only the token column inside students and put them in my array named studentTokens. Here is the code

public static void main(String[] args) {
    ArrayList<String > studentTokens = new ArrayList<String>();

    try{
        // Open the file that is the first 
        // command line parameter
        FileInputStream fstream = new  FileInputStream("c:/work/data1.txt");

        // Get the object of DataInputStream
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String strLine;

        //Read File Line By Line
        while ((strLine = br.readLine()) != null)   {
            // Print the content on the console
            System.out.println (strLine);
        }

        //Close the input stream
        in.close();
    }catch (Exception e){//Catch exception if any
        System.err.println("Error: " + e.getMessage());
    }
}

Answer 1

短ip:

private static Integer STUDENT_ID_COLUMN = 0;
private static Integer STUDENT_KEY_COLUMN = 1;
private static Integer YEAR_LEVEL_COLUMN = 2;
private static Integer STUDENT_NAME_COLUMN = 3;
private static Integer TOKEN_COLUMN = 4;

public static void main(String[] args) {

    ArrayList<String> studentTokens = new ArrayList<>();

    try (FileInputStream fstream = new FileInputStream("test.txt");
          InputStreamReader inputStreamReader = new InputStreamReader(fstream);
          BufferedReader br = new BufferedReader(inputStreamReader)) {

        String strLine;

        // Read File Line By Line
        while ((strLine = br.readLine()) != null) {

            strLine = strLine.trim();

            if ((strLine.length() != 0) && (strLine.charAt(0) !=  # )) {
                String[] columns = strLine.split("\s+");
                studentTokens.add(columns[TOKEN_COLUMN]);
            }

        }
    }
    catch (Exception e) {// Catch exception if any
        System.err.println("Error: " + e.getMessage());
        return;
    }

    for (String s : studentTokens) {
        System.out.println(s);
    }
}

The above code is not complete solution. It extracts all tokens (for students and teachers). I hope you ll manage to make it work just for student tokens from there on...

Answer 2

你们必须考虑转向java.nio ,但现在有一些冰箱要与他人合作。

这里是一部小型法典,将给你带来预期结果。

import java.io.BufferedReader;

import java.nio.charset.Charset;

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import java.util.ArrayList;
import java.util.List;

public class StudentToken
{
    public static void main(String[] args) throws Exception
    {       
        List<String> studenttoken = new ArrayList<String>();
        Path sourcePath = Paths.get(args[0]);
        Charset charset = Charset.forName("US-ASCII");
        BufferedReader reader = Files.newBufferedReader(sourcePath, charset);
        int width = 0;
        int height = 0;

        String line = null;     
        line = reader.readLine();
        while (!((line = reader.readLine()).trim()).equals("#Teachers"))
        {       
            line = line.trim();
            if (width == 0)
            {
                String[] str = line.split("\s+");
                width = str.length;
            }           
            if (line.length() > 0)  
            height++;
        }
        reader.close();

        BufferedReader reader1 = Files.newBufferedReader(sourcePath, charset);
        reader1.readLine();
        for (int i = 0; i < height; i++)
        {
            if(!((line = reader1.readLine()).trim()).equals("#Teachers"))
            {
                line = line.trim();
                String[] str = line.split("\s+");
                for (int j = 0; j < width; j++)
                {
                              // this condition will add only those elements which fall under token column.
                    if (j == (height) && i != 0) 
                        studenttoken.add(str[j]);                   
                }
            }
        }
        reader1.close();
        System.out.println(studenttoken);
    }
}

试验产出如下:

Hopefully that might help. Regards.

Answer 3

您可以按行文读到档案线,并使用String.split(“s+”)。

Answer 4

查阅 String.split,这将有助于你在空间上分立每一条线。一旦分离,你就能够收回被打字栏的价值。最后,请ArrayList.add,将其添加到您的名单上。

Answer 5

You are simple printing the line . I believe there are can be two ways Since your token element is the fifth element, you can split the string and utilize the 5th element directly

String splitString = strLine.split(" "); String tokenvalue = splitString[4];

或作为轻松操纵的卷宗

友情链接