Android从本地选择文件并判断文件类型并获取选到文件大小的方法

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最近有一个android选择本地文件的并判断文件类型的需求

首先要选择文件通过点击事件进入到文件列表这里是浏览所有的文件。用到的是startActivityForResult

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);intent.setType("*/*");intent.addCategory(Intent.CATEGORY_OPENABLE);startActivityForResult(Intent.createChooser(intent, "Select a File to Upload"), 1);

然后在这个页面重写onActivytResult这个方法

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {   super.onActivityResult(requestCode, resultCode, data);      if (resultCode == Activity.RESULT_OK) {         if (data != null) {            final Uri uri = data.getData();            String path = getPath(this, uri);            /*这里要调用这个getPath方法来能过uri获取路径不能直接使用uri.getPath。            因为如果选的图片的话直接使用得到的path不是图片的本身路径*/               File file = new File(path);             /* 取得扩展名 */               String end = file.getName().substring(file.getName().lastIndexOf(".") + 1, file.getName().length()).toLowerCase();               /* 依扩展名的类型决定MimeType 这里只用了pdf word 图片更类型可查http://www.cnblogs.com/hibraincol/archive/2010/09/16/1828502.html*/               if (end.equals("jpg") || end.equals("gif") || end.equals("png") ||                     end.equals("jpeg") || end.equals("bmp")) {                  try {//图片                     String daxiao = FormentFileSize(getFileSizes(file));//获取文件大小的方法                     fileDatas.add(new FilesParam(daxiao, path, file.getName()));                     Hadapter.notifyDataSetChanged();//更新listview显示本图片                  } catch (Exception e) {                     e.printStackTrace();                  }               } else if (end.equals("doc")) {                  try {//word                     String daxiao = FormentFileSize(getFileSizes(file));                     fileDatas.add(new FilesParam(daxiao, "DOC", file.getName()));                     Hadapter.notifyDataSetChanged();                  } catch (Exception e) {                     e.printStackTrace();                  }               } else if (end.equals("pdf")) {                  try {//pdf                     String daxiao = FormentFileSize(getFileSizes(file));                     fileDatas.add(new FilesParam(daxiao, "PDF", file.getName()));                     Hadapter.notifyDataSetChanged();                  } catch (Exception e) {                     e.printStackTrace();                  }               } else if (end.equals("txt")) {                  try {//text                     String daxiao = FormentFileSize(getFileSizes(file));                     fileDatas.add(new FilesParam(daxiao, "DOC", file.getName()));                     Hadapter.notifyDataSetChanged();                  } catch (Exception e) {                     e.printStackTrace();                  }               } else {                  Toast.makeText(this, "只能选择图片、文档、PDF三种格式", Toast.LENGTH_SHORT).show();               }            }

         }   }

下面是上面中提到的获取文件路径和文件大小的方法。值得注意的是在Android4.4以前可以通过data.getpath()来直接得到文件路径，但是4.4以后通过这个方法得到是路径不是正确路径（这里说的是图片）所以我们用下面getPath（）方法来解决这个问题。别外在6.0版本以后读写文件要有运行时权限

//得到正确路径public static String getPath(Context context, Uri uri) {  final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;//sdk版本是否大于4.4   // DocumentProvider   if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {      // ExternalStorageProvider      if (isExternalStorageDocument(uri)) {         final String docId = DocumentsContract.getDocumentId(uri);         final String[] split = docId.split(":");         final String type = split[0];         if ("primary".equalsIgnoreCase(type)) {            return Environment.getExternalStorageDirectory() + "/" + split[1];         }         // TODO handle non-primary volumes      }else if (isDownloadsDocument(uri)) {         final String id = DocumentsContract.getDocumentId(uri);         final Uri contentUri = ContentUris.withAppendedId(               Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));         return getDataColumn(context, contentUri, null, null);      }      // MediaProvider      else if (isMediaDocument(uri)) {         final String docId = DocumentsContract.getDocumentId(uri);         final String[] split = docId.split(":");         final String type = split[0];         Uri contentUri = null;         if ("image".equals(type)) {            contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;         } else if ("video".equals(type)) {            contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;         } else if ("audio".equals(type)) {            contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;         }         final String selection = "_id=?";         final String[] selectionArgs = new String[]{               split[1]         };         return getDataColumn(context, contentUri, selection, selectionArgs);      }   }   // MediaStore (and general)   else if ("content".equalsIgnoreCase(uri.getScheme())) {      // Return the remote address      if (isGooglePhotosUri(uri))         return uri.getLastPathSegment();      return getDataColumn(context, uri, null, null);   }   // File   else if ("file".equalsIgnoreCase(uri.getScheme())) {      return uri.getPath();   }return null;
}

下面这些是getPath中要调用的方法

public static boolean isExternalStorageDocument(Uri uri) {   return "com.android.externalstorage.documents".equals(uri.getAuthority());}public static boolean isDownloadsDocument(Uri uri) {   return "com.android.providers.downloads.documents".equals(uri.getAuthority());}public static boolean isMediaDocument(Uri uri) {   return "com.android.providers.media.documents".equals(uri.getAuthority());}public static boolean isGooglePhotosUri(Uri uri) {   return "com.google.android.apps.photos.content".equals(uri.getAuthority());}public static String getDataColumn(Context context, Uri uri, String selection,                           String[] selectionArgs) {   Cursor cursor = null;   final String column = "_data";   final String[] projection = {column};   try {      cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,            null);      if (cursor != null && cursor.moveToFirst()) {         final int index = cursor.getColumnIndexOrThrow(column);         return cursor.getString(index);      }   } finally {      if (cursor != null)         cursor.close();   }   return null;}

/*得到传入文件的大小*/public static long getFileSizes(File f) throws Exception {   long s = 0;   if (f.exists()) {      FileInputStream fis = null;      fis = new FileInputStream(f);      s = fis.available();      fis.close();   } else {      f.createNewFile();      System.out.println("文件夹不存在");   }   return s;}/** * 转换文件大小成KB  M等 */public static String FormentFileSize(long fileS) {   DecimalFormat df = new DecimalFormat("#.00");   String fileSizeString = "";   if (fileS < 1024) {      fileSizeString = df.format((double) fileS) + "B";   } else if (fileS < 1048576) {      fileSizeString = df.format((double) fileS / 1024) + "K";   } else if (fileS < 1073741824) {      fileSizeString = df.format((double) fileS / 1048576) + "M";   } else {      fileSizeString = df.format((double) fileS / 1073741824) + "G";   }   return fileSizeString;}

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