Android: Reading txt file using implicit intent

2019-03-06 15:23发布

问题:

Problem : I'm trying to open a txt file using implicit Intent(ACTION_GET_CONTENT) and store the txt file's content into an arraylist. When I try to open the file with file path from Uri's getPath() and create a BufferedReader object to read from the text file, I get an error says that such file path does not exist.

In Logcat, it says my file path is "/document/1505-2A0C:Download/text.txt" and when I try to open the file it says:

"W/System.err: java.io.FileNotFoundException:
        /document/1505-2A0C:Download/text.txt: open failed: 
        ENOENT (No such file or directory)"

Here's my code:

@Override
public void onClick(View v) {
    // Send implicit intent to load a file from directory
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("text/plain");
    startActivityForResult(Intent.createChooser(intent, 
           "Load a file from directory"), REQUEST_CODE_SEARCH);
}

onActivityResult():

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_SEARCH) {
        try {
            Uri uri = data.getData();
            String filepath = uri.getPath();

            // In logcat : File path: /document/1505-2A0C:Download/text.txt
            Log.d("File path", filepath);

            File file = new File(filepath);
            ArrayList<String> strings = new ArrayList<>();

            /* Problem occurs here : I do not get correct file path to open a FileReader.
            In logcat: "W/System.err: java.io.FileNotFoundException:
            /document/1505-2A0C:Download/text.txt: open failed: 
            ENOENT (No such file or directory)"*/
            BufferedReader br = new BufferedReader(new FileReader(file));

            // Rest of code that converts txt file's content into arraylist
        } catch (IOException e) {
            // Codes that handles IOException
        }
    }
}

In summary : I get "/document/1505-2A0C:Download/text.txt" for file path, and when I open the file in BufferedReader using the file path, it says there is no such directory.

What am I doing wrong in here?

回答1:

When I try to open the file with file path from Uri's getPath() and create a BufferedReader object to read from the text file, I get an error says that such file path does not exist.

That is because ACTION_GET_CONTENT does not return a file. It returns a Uri, and that Uri does not have to point to a file.

Get rid of all the File stuff. Use a ContentResolver and openInputStream() to get an InputStream on the content identified by the Uri. Read in your text using that InputStream.