In depth understanding of file operation mode developed by Android
- 2020-05-07 20:22:37
- OfStack
1. Basic concept
private mode
Can only be accessed by the current application that created the file
If the file does not exist will create a file; If the created file already exists, the original file is overwritten
Context.MODE_PRIVATE = 0;
append mode
(1) private
If the file does not exist will create a file; Appends to the end of the file if it exists
Context.MODE_APPEND = 32768;
readable mode
The file created can be read by other applications
Context.MODE_WORLD_READABLE=1;
writable mode
Allows other applications to write to it.
Context.MODE_WORLD_WRITEABLE=2
2. Use in combination
Allows other applications to read and write and override by default
Append mode, but allow other applications to read and write
// Context object
private Context context;
public FileService(Context context)
{
super();
this.context = context;
}
// Save file method
public void save(String filename, String fileContent) throws Exception
{
FileOutputStream fos = context.openFileOutput(filename, context.MODE_PRIVATE);
fos.write(fileContent.getBytes("UTF-8"));
fos.close();
}
private mode
Can only be accessed by the current application that created the file
If the file does not exist will create a file; If the created file already exists, the original file is overwritten
Context.MODE_PRIVATE = 0;
append mode
(1) private
If the file does not exist will create a file; Appends to the end of the file if it exists
Context.MODE_APPEND = 32768;
readable mode
The file created can be read by other applications
Context.MODE_WORLD_READABLE=1;
writable mode
Allows other applications to write to it.
Context.MODE_WORLD_WRITEABLE=2
2. Use in combination
FileOutputStream outStream = this.openFileOutput("xy.txt",Context.MODE_WORLD_READABLE+Context.MODE_WORLD_WRITEABLE);
Allows other applications to read and write and override by default
FileOutputStream outStream = this.openFileOutput("xy.txt",Context.MODE_APPEND+Context.MODE_WORLD_READABLE+Context.MODE_WORLD_WRITEABLE);
Append mode, but allow other applications to read and write