Android：无法使用FileInputStream从文件读取

Question

I'm trying to read from a file called "quiz_questions.txt" in my res/raw folder. The code I have compiles, but it looks like it stops before it gets to the FileInputStream. Maybe it is opening it, but not reading it. I'm not sure.

import java.io.*;
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;

public class Questions extends Activity {

public String[][] questions = new String[10][5];

public void fillArray() {
    {
        Context con = null;
        try {
            //fis = new BufferedInputStream(new FileInputStream("res/raw/quiz_questions.txt"));
            FileInputStream fis = (FileInputStream) con.getResources().openRawResource(R.raw.quiz_questions);
            BufferedReader br = new BufferedReader(new InputStreamReader(fis));
            String nextLine;
            int i = 0, j = 0;
            while ((nextLine = br.readLine()) != null) {
                if (j == 5) {
                    j = 0;
                    i++;
                }
                questions[i][j] = nextLine;
            }
            fis.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
}

Answer 1

You don't post it, but I imagine that you are getting a NullPointerException. This is because con is null when you try to create the FileInputStream .

Since an Activity is already a Context , you can just eliminate con from the statement. (You should also use the InputStream interface instead of FileInputStream .)

InputStream is = getResources().openRawResource(R.raw.quiz_questions);

Finally, you should reorganize your code so is is closed whether or not an exception is thrown:

public void fillArray() {
    try (InputStream is = getResources().openRawResource(R.raw.quiz_questions)) {
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        String nextLine;
        int i = 0, j = 0;
        while ((nextLine = br.readLine()) != null) {
            if (j == 5) {
                j = 0;
                i++;
            }
            questions[i][j] = nextLine;
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}