Android:使用隐式意图读取txt文件 [英] Android: Reading txt file using implicit intent

问题描述

问题:我正在尝试使用隐式Intent(ACTION_GET_CONTENT)打开txt文件，并将txt文件的内容存储到arraylist中.当我尝试用Uri的getPath()文件路径打开文件并创建一个BufferedReader对象以从文本文件中读取时，出现错误消息说该文件路径不存在.

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.

在Logcat中，它说我的文件路径是"/document/1505-2A0C:Download/text.txt" 当我尝试打开文件时说:

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)"

这是我的代码:

@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
        }
    }
}

总结:我得到"/document/1505-2A0C:Download/text.txt"的文件路径，当我使用文件路径在BufferedReader中打开文件时，它说没有这样的目录.

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.

我在这里做什么错了?

推荐答案

当我尝试使用Uri的getPath()中的文件路径打开文件并创建一个BufferedReader对象以从文本文件中读取时，我收到一条错误消息，指出该文件路径不存在.

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.

这是因为ACTION_GET_CONTENT不返回文件.它返回Uri，而Uri不必指向文件.

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.

清除所有File内容.使用ContentResolver和openInputStream()在Uri标识的内容上获取InputStream.使用该InputStream读入您的文本.

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.

这篇关于Android:使用隐式意图读取txt文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！