从java（android）中的文件路径获取目录

Question

Is there a function to get the directory part of a file path?

so from

String a="/root/sdcard/Pictures/img0001.jpg";

you get

"/root/sdcard/Pictures"

Answer 1

Yes. First, construct a File representing the image path:

File file = new File(a);

If you're starting from a relative path:

file = new File(file.getAbsolutePath());

Then, get the parent :

String dir = file.getParent();

Or, if you want the directory as a File object,

File dirAsFile = file.getParentFile();

Answer 2

A better way, use getParent() from File Class..

String a="/root/sdcard/Pictures/img0001.jpg"; // A valid file path 
File file = new File(a); 
String getDirectoryPath = file.getParent(); // Only return path if physical file exist else return null

http://developer.android.com/reference/java/io/File.html#getParent%28%29

Answer 3

You could also use FilenameUtils from Apache . It provides you at least the following features for the example C:\\dev\\project\\file.txt:

• the prefix - C:\\
• the path - dev\\project\\
• the full path - C:\\dev\\project\\
• the name - file.txt
• the base name - file
• the extension - txt

Answer 4

I have got solution on this after 4 days, Please note following points while giving path to File class in Android(Java):

1. Use path for internal storage String path="/storage/sdcard0/myfile.txt";
2. path="/storage/sdcard1/myfile.txt";

3. mention permissions in Manifest file.

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

4. First check file length for confirmation.
5. Check paths in ES File Explorer regarding sdcard0 & sdcard1 is this same or else......

eg

File file=new File(path);
long=file.length();//in Bytes