Android File Operation detailed

Android file operations should have permission:

Determine if the SD card is plugged in

Environment.getexternalstoragestate (). Equals (

Android.os.Environment.MEDIA_MOUNTED);

Get SD Card root directory

File skroot = Environment.getexternalstoragedirectory ();

Get the private root directory

File fileroot = Context.getfilesdir () + "";

Identify or get folder and file paths

String path = File.getpath ();//Relative

String path = File.getabsoultepath ();//Absolute

Get the parent directory of a file or folder

String Parentpath = File.getparent ()

To obtain the name of a file or folder:

String Name = File.getname ();

Create a file or folder

File.createnewfile ()//Create a file

Judgment is a file or folder

File.isdirectory ()

List all file and folder names under the folder

file[] files = file.listfiles ();

modifying folders and file names

File.renameto (dest);

Delete a folder or file

File.delete ();

File read and write operation mode

Context.mode_private: New content covering the original content

Context.mode_append: After the new content is appended to the original content

Context.mode_world_readable: Allow other applications to read

Context.mode_world_writeable: Allows other applications to write, overwriting the original data.

/*** Save File

* @param fileName

* @param filecontent

* @throws exception*/

public void Save (string fileName, String filecontent) throws Exception {

The parent of the activity's parent class is that Context,context is the same as the context in other frameworks for us to provide some core operational tools.

FileOutputStream FileOutputStream = This.context.openFileOutput (

FileName, context.mode_private);

Fileoutputstream.write (Filecontent.getbytes ());

}

/**

* Read files

*

* @param fileName

* @return

* @throws Exception

*/

Public String Read (String fileName) throws Exception {

FileInputStream FileInputStream = This.context.openFileInput (fileName);

Bytearrayoutputstream ByteArray = new Bytearrayoutputstream ();

byte[] buffer = new byte[1024];

int len = 0;

while (len = fileinputstream.read (buffer)) > 0) {

Bytearray.write (buffer, 0, Len);

};

return bytearray.tostring ();

}

}