从不扩展AppCompatActivity的类从Android Studio上的内部存储打开文件

Question

Is it possible to read a file from internal storage in a utility class that doesn't extend anything? I have the code below to read a file, but I can't use the openFileInput method because it doesn't exist. Is there something I have to import to read these files?

private String readFromFile(String fileName) {
    FileInputStream fis = null;
    try {
        fis = openFileInput("Links"); // this doesn't compile in a utility class
        InputStreamReader isr = new InputStreamReader(fis);
        BufferedReader bufferedReader = new BufferedReader(isr);
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            sb.append(line);
        }
        return String.valueOf(sb);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Answer 1

You can use java.io.FileInputStream

private String readFromFile(String fileName) {
    InputStream in = null;
    try {
        in = new FileInputStream(fileName);
        InputStreamReader isr = new InputStreamReader(in);
        BufferedReader bufferedReader = new BufferedReader(isr);
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            sb.append(line);
        }
        return String.valueOf(sb);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}