在Android中从外部存储打开文件 [英] Open file from external storage in Android

问题描述

这可能是一种快速修复方法，但是目前我无法正常工作...

This could probably be a fast fix but currently I am unable to get this working...

我在解析XML文件时有一个asynctask.如果我将XML文件放在资产文件夹中，则可以打开并解析它.

I have an asynctask where I am parsing a XML file. If I place an XML file in the assets folder i can open and parse it no problem.

但是，如果我尝试从外部存储打开XML文件，则会失败.

But if I try to open a XML file from external storage it fails.

这是我的异步任务:

private class async extends AsyncTask<String, Void, Void> {
@Override
protected Void doInBackground(String... params) {
    while (!isCancelled()) {

     try {
         NodeList nList;
         Node node;

         InputStream is = getAssets().open("file.xml");
         // this works

         File is = new File("/storage/emulated/0/test.xml");
         // this fails

         DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
         DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
         Document doc = dBuilder.parse(is);

我收到此错误:

I/System.out: File path: /storage/emulated/0/test.xml
W/System.err: java.io.FileNotFoundException: /storage/emulated/0/test.xml (Permission denied)

这些权限在我的清单中:

These permissions are in my manifest:

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

有人可以告诉我为什么我会收到此错误吗?

Could someone tell me why I am getting this error?

谢谢！

推荐答案

我看到了您的错误消息:

I see your error message :

java.io.FileNotFoundException:/storage/emulated/0/test.xml(权限被拒绝)

java.io.FileNotFoundException: /storage/emulated/0/test.xml (Permission denied)

请记住，您必须在运行Android 6.0的操作系统上运行必须实现 尝试读取或写入外部存储之前的运行时权限.

Remember that running on running Android 6.0 you must implement runtime permissions before you try to read or write the external storage.

将其设置为manifest.xml对于使用Android 6.0及更高版本的设备是不够的:

setting this into your manifest.xml is not enough for devices with Android 6.0+:

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

这篇关于在Android中从外部存储打开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！