Android File Explorer with JPG's Exif info

In the last exercise, Implement a simple File Explorer in Android, if a file is clicked, the application will simple display the file name only. Here, a little bit function will be add: if it's a JPG/jpg file, its Exif attributes will be listed also. This function have been described in former article, Read Exif information in a JPEG file, ExifInterface.




To check a file's extention in Java, the following code can be used:

   String filename = file.getName();
   String ext = filename.substring(filename.lastIndexOf('.')+1, filename.length());

   if(ext.equals("JPG")||ext.equals("jpg"))
   {}

To implement the Exif function in the application, it involve modification on the method onListItemClick(), and two more methods; getExif() and getTagString().

 @Override
 protected void onListItemClick(ListView l, View v, int position, long id) {
  
  File file = new File(path.get(position));
  
  if (file.isDirectory())
  {
   if(file.canRead())
    getDir(path.get(position));
   else
   {
    new AlertDialog.Builder(this)
    .setIcon(R.drawable.icon)
    .setTitle("[" + file.getName() + "] folder can't be read!")
    .setPositiveButton("OK", 
      new DialogInterface.OnClickListener() {
       
       @Override
       public void onClick(DialogInterface dialog, int which) {
        // TODO Auto-generated method stub
       }
      }).show();
   }
  }
  else
  {
   String exifAttribute = null;
   String filename = file.getName();
   String ext = filename.substring(filename.lastIndexOf('.')+1, filename.length());

   if(ext.equals("JPG")||ext.equals("jpg"))
   {
    try {
     ExifInterface exif = new ExifInterface(file.toString());
     exifAttribute = getExif(exif);
    } catch (IOException e) {
     // TODO Auto-generated catch block
     ;
    }
   }
   
   new AlertDialog.Builder(this)
    .setIcon(R.drawable.icon)
    .setTitle("[" + filename + "]")
    .setMessage(exifAttribute)
    .setPositiveButton("OK", 
      new DialogInterface.OnClickListener() {
       
       @Override
       public void onClick(DialogInterface dialog, int which) {
        // TODO Auto-generated method stub
       }
      }).show();
  }
 }
 
    private String getExif(ExifInterface exif)
    {
     String myAttribute=null;
     myAttribute += getTagString(ExifInterface.TAG_DATETIME, exif);
     myAttribute += getTagString(ExifInterface.TAG_FLASH, exif);
     myAttribute += getTagString(ExifInterface.TAG_GPS_LATITUDE, exif);
     myAttribute += getTagString(ExifInterface.TAG_GPS_LATITUDE_REF, exif);
     myAttribute += getTagString(ExifInterface.TAG_GPS_LONGITUDE, exif);
     myAttribute += getTagString(ExifInterface.TAG_GPS_LONGITUDE_REF, exif);
     myAttribute += getTagString(ExifInterface.TAG_IMAGE_LENGTH, exif);
     myAttribute += getTagString(ExifInterface.TAG_IMAGE_WIDTH, exif);
     myAttribute += getTagString(ExifInterface.TAG_MAKE, exif);
     myAttribute += getTagString(ExifInterface.TAG_MODEL, exif);
     myAttribute += getTagString(ExifInterface.TAG_ORIENTATION, exif);
     myAttribute += getTagString(ExifInterface.TAG_WHITE_BALANCE, exif);
     return myAttribute;
    }
    
    private String getTagString(String tag, ExifInterface exif)
    {
     return(tag + " : " + exif.getAttribute(tag) + "\n");
    }

Next: Android File Explorer with JPG's Exif & Photo displayed


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