【发布时间】:2017-04-25 17:34:08
【问题描述】:
我创建了一个应用程序,允许用户创建笔记并保存它。
我知道数据存储在应用程序的私有存储区域,但我需要通过文件路径实际查看存储数据的文件。谁能帮助我如何做到这一点?我使用了 FileOutputStream 和 FileInputStream 方法
public class Utilities {
public static final String FILE_EXTENSION = ".bin";
public static boolean saveNote(Context context, Notes notes){
String fileName = String.valueOf(notes.getDateTime()) + FILE_EXTENSION;
FileOutputStream fos;
ObjectOutputStream oos;
try {
fos = context.openFileOutput(fileName, context.MODE_PRIVATE);
oos = new ObjectOutputStream(fos);
oos.writeObject(notes);
oos.close();
fos.close();
} catch (IOException e) {
e.printStackTrace();
return false; //tell the user something went wrong
}
return true;
}
public static ArrayList<Notes> getSavedNotes(Context context) {
ArrayList<Notes> notes = new ArrayList<>();
File filesDir = context.getFilesDir();
ArrayList<String> noteFiles = new ArrayList<>();
for(String file : filesDir.list()) {
if(file.endsWith(FILE_EXTENSION)) {
noteFiles.add(file);
}
}
FileInputStream fis;
ObjectInputStream ois;
for(int i = 0; i < noteFiles.size(); i++) {
try{
fis = context.openFileInput(noteFiles.get(i));
ois = new ObjectInputStream(fis);
notes.add((Notes)ois.readObject());
fis.close();
ois.close();
} catch (IOException | ClassNotFoundException e) {
e.printStackTrace();
return null;
}
}
return notes;
}
public static Notes getNoteByName(Context context, String fileName) {
File file = new File(context.getFilesDir(), fileName);
Notes notes;
if(file.exists()) {
FileInputStream fis;
ObjectInputStream ois;
try {
fis = context.openFileInput(fileName);
ois = new ObjectInputStream(fis);
notes = (Notes) ois.readObject();
fis.close();
ois.close();
} catch(IOException | ClassNotFoundException e){
e.printStackTrace();
return null;
}
return notes;
}
return null;
}
public static void deleteNote(Context context, String fileName) {
File Dir = context.getFilesDir();
File file = new File(Dir, fileName);
if(file.exists()) {
file.delete();
}
}
}
【问题讨论】: