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androidfile-iofileoutputstreamfileinputstreamandroid-file

Read/write file to internal private storage


I'm porting the application from Symbian/iPhone to Android, part of which is saving some data into file. I used the FileOutputStream to save the file into private folder /data/data/package_name/files:

FileOutputStream fos = iContext.openFileOutput( IDS_LIST_FILE_NAME, Context.MODE_PRIVATE ); 
fos.write( data.getBytes() ); 
fos.close();

Now I am looking for a way how to load them. I am using the FileInputStream, but it allows me to read the file byte by byte, which is pretty inefficient:

int ch;
StringBuffer fileContent = new StringBuffer("");
FileInputStream fis = iContext.openFileInput( IDS_LIST_FILE_NAME );
while( (ch = fis.read()) != -1)
  fileContent.append((char)ch);
String data = new String(fileContent);

So my question is how to read the file using better way?


Solution

  • Using FileInputStream.read(byte[]) you can read much more efficiently.

    In general you don't want to be reading arbitrary-sized files into memory.

    Most parsers will take an InputStream. Perhaps you could let us know how you're using the file and we could suggest a better fit.

    Here is how you use the byte buffer version of read():

    byte[] buffer = new byte[1024];
    int length;
    while ((length = fis.read(buffer)) != -1) {
        fileContent.append(new String(buffer));
    }