Android 11 分区存储

场景

从微信打开KML文件，选择自家开发的App打开，发现能够读取读取文件路径，但是在操作的时候显示错误

java.io.FileNotFoundException: /storage/emulated/0/Android/data/com.tencent.mm/MicroMsg/Download/xxx.kml: open failed: EACCES (Permission denied)

其中AS工程已经正确配置存储权限，并且application已经配置android:requestLegacyExternalStorage="true"

因项目在Android10上能够正确运行，但是在Android 11及以上有异常，猜想是因为Android 11做了一些限制。

因此采用另外一种方法：先把真实路径从获取到的Uri对象中解析出来，然后把文件拷贝一份到App目录下面，再对这个文件进行解析

/**
     *  从Uri获取真实路径
     * @param context
     * @param uri
     * @return
     */
    public static String getFPUriToPath(Context context, Uri uri) {
        try {
            List<PackageInfo> packs = context.getPackageManager().getInstalledPackages(PackageManager.GET_PROVIDERS);
            if (packs != null) {
                String fileProviderClassName = FileProvider.class.getName();
                for (PackageInfo pack : packs) {
                    ProviderInfo[] providers = pack.providers;
                    if (providers != null) {
                        for (ProviderInfo provider : providers) {
                            if (uri.getAuthority().equals(provider.authority)) {
//                                if (provider.name.equalsIgnoreCase(fileProviderClassName)) {
                                    Class<FileProvider> fileProviderClass = FileProvider.class;
                                    try {
                                        Method getPathStrategy = fileProviderClass.getDeclaredMethod("getPathStrategy", Context.class, String.class);
                                        getPathStrategy.setAccessible(true);
                                        Object invoke = getPathStrategy.invoke(null, context, uri.getAuthority());
                                        if (invoke != null) {
                                            String PathStrategyStringClass = FileProvider.class.getName() + "$PathStrategy";
                                            Class<?> PathStrategy = Class.forName(PathStrategyStringClass);
                                            Method getFileForUri = PathStrategy.getDeclaredMethod("getFileForUri", Uri.class);
                                            getFileForUri.setAccessible(true);
                                            Object invoke1 = getFileForUri.invoke(invoke, uri);
                                            if (invoke1 instanceof File) {
                                                return ((File) invoke1).getAbsolutePath();
                                            }
                                        }
                                    } catch (NoSuchMethodException e) {
                                        e.printStackTrace();
                                    } catch (InvocationTargetException e) {
                                        e.printStackTrace();
                                    } catch (IllegalAccessException e) {
                                        e.printStackTrace();
                                    } catch (ClassNotFoundException e) {
                                        e.printStackTrace();
                                    }
                                    break;
//                                }
//                                break;
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

/**
     * 用流拷贝文件一份到自己APP目录下
     *
     * @param context
     * @param uri
     * @param fileName
     * @return
     */
public static String getPathFromInputStreamUri(Context context, Uri uri, String fileName) {
        InputStream inputStream = null;
        String filePath = null;

        if (uri.getAuthority() != null) {
            try {
                inputStream = context.getContentResolver().openInputStream(uri);
                File file = createTemporalFileFrom(context, inputStream, fileName);
                filePath = file.getPath();

            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    if (inputStream != null) {
                        inputStream.close();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

        return filePath;
    }

    private static File createTemporalFileFrom(Context context, InputStream inputStream, String fileName)
            throws IOException {
        File targetFile = null;

        if (inputStream != null) {
            int read;
            byte[] buffer = new byte[8 * 1024];
            //自己定义拷贝文件路径
            targetFile = new File(context.getCacheDir(), fileName);
            if (targetFile.exists()) {
                targetFile.delete();
            }
            OutputStream outputStream = new FileOutputStream(targetFile);

            while ((read = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, read);
            }
            outputStream.flush();

            try {
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return targetFile;
    }