Question

Function ” writeToFile() ” will be rapidly called to write string to text file .
but I didn’t see any text in the file .

code:

 public class MyClass {
        private File data_file = new File("data_from_java.txt");
        public void writeToFile(String str){
        try {
            FileOutputStream fos= new FileOutputStream(this.data_file, true);
            System.out.print(str);  // there is text shown in terminal 
            fos.write(str.getBytes());
            fos.flush();
            fos.close();   // why file donesn't have text 
        }catch(Exception ex) {
            System.out.println(ex.getMessage());
        }
    }

Answer 1

Writing raw bytes may cause problems with character encoding. As Jon Skeet said, use a writer…

try {
    FileWriter writer = new FileWriter(data_file, true);
    writer.write(str);
} catch(IOException e) {
    // oh no!
} finally {
    writer.close();
}