Android reads and writes files

1. Get the file from the raw folder in the resource and read the data (the resource file can only be read but cannot be written)
String res = "";

Try {

InputStream in = getResources (). openRawResource (R. raw. bbi );

// In \ Test \ res \ raw \ bbi.txt,

Int length = in. available ();

Byte [] buffer = new byte [length];

In. read (buffer );

// Res = EncodingUtils. getString (buffer, "UTF-8 ");

// Res = EncodingUtils. getString (buffer, "UNICODE ");

Res = EncodingUtils. getString (buffer, "BIG5 ");

// Select an appropriate encoding type based on bbi.txt. If this parameter is not adjusted, garbled characters are returned.

In. close ();

} Catch (Exception e ){

E. printStackTrace ();

}

MyTextView. setText (res); // display the obtained content on TextView.

 

2. Get files from asset and read data (resource files can only be read but cannot be written)
String fileName = "yan.txt"; // file name

String res = "";

Try {

InputStream in = getResources (). getAssets (). open (fileName );

// \ Test \ assets \ yan.txt this file exists

Int length = in. available ();

Byte [] buffer = new byte [length];

In. read (buffer );

Res = EncodingUtils. getString (buffer, "UTF-8 ");

} Catch (Exception e ){

E. printStackTrace ();

}

 

3. to read a file from sdcard, first copy the file on your computer to sdcardthrough \ android-sdk-windows \ tools \ adb.exe. adb.exe pushes e:/Y.txt/sdcard/, which is not applicable to adb.exe push e: \ Y.txt \ sdcard \ similarly: copy the file on the simulator to a local computer and use adb pull. /data/com. tt/files/Test.txt e :/
 

String fileName = "/sdcard/Y.txt ";

// You can also use String fileName = "mnt/sdcard/Y.txt ";

String res = "";

Try {

FileInputStream fin = new FileInputStream (fileName );

// FileInputStream fin = openFileInput (fileName );

// This will not work. You must use FileInputStream.

Int length = fin. available ();

Byte [] buffer = new byte [length];

Fin. read (buffer );

Res = EncodingUtils. getString (buffer, "UTF-8 ");

Fin. close ();

} Catch (Exception e ){

E. printStackTrace ();

}

MyTextView. setText (res );

 

4. Write files, which are generally written in \ data \ com. test \ files \. Open DDMS to view the structure of file explorer.
String fileName = "TEST.txt ";

String message = "FFFFFFF11111FFFFF ";

WriteFileData (fileName, message );

 

Public voidwriteFileData (String fileName, String message ){

Try {

FileOutputStream fout = openFileOutput (fileName, MODE_PRIVATE );

Byte [] bytes = message. getBytes ();

Fout. write (bytes );

Fout. close ();

}

Catch (Exception e ){

E. printStackTrace ();

}

}

 

5. write and read files in the data/directory (equivalent to the AP working directory). Use openFileOutput
// Write the file under./data/com. tt/files/

Public voidwriteFileData (String fileName, String message ){

Try {

FileOutputStream fout = openFileOutput (fileName, MODE_PRIVATE );

Byte [] bytes = message. getBytes ();

Fout. write (bytes );

Fout. close ();

}

Catch (Exception e ){

E. printStackTrace ();

}

}

//-------------------------------------------------------

// Read the file under./data/com. tt/files/

Public String readFileData (String fileName ){

String res = "";

Try {

FileInputStream fin = openFileInput (fileName );

Int length = fin. available ();

Byte [] buffer = new byte [length];

Fin. read (buffer );

Res = EncodingUtils. getString (buffer, "UTF-8 ");

Fin. close ();

}

Catch (Exception e ){

E. printStackTrace ();

}

Return res;

}

6. write and read the files in the sdcard directory. Use FileOutputStream instead of openFileOutput.
 

// File written in the/mnt/sdcard/directory

Public voidwriteFileSdcard (String fileName, String message ){

Try {

// FileOutputStream fout = openFileOutput (fileName, MODE_PRIVATE );

FileOutputStream fout = newFileOutputStream (fileName );

Byte [] bytes = message. getBytes ();

Fout. write (bytes );

Fout. close ();

}

Catch (Exception e ){

E. printStackTrace ();

}

}

 

// Read the files in the/mnt/sdcard/directory

Public String readFileSdcard (String fileName ){

String res = "";

Try {

FileInputStream fin = new FileInputStream (fileName );

Int length = fin. available ();

Byte [] buffer = new byte [length];

Fin. read (buffer );

Res = EncodingUtils. getString (buffer, "UTF-8 ");

Fin. close ();

}

Catch (Exception e ){

E. printStackTrace ();

}

Return res;

}
Author: yilip