【Android】记录一次安卓10的图片读取

非常的难受，这个读写内容。因为Android 10没有读取sd的权限了，Android 11都恢复了部分读写权限，但是Android 10的适配是真的难受。

好在有内容提供者这个组件，通过这个中介可以获取Uri，再从Uri转为InputSteam，之后转为byte[]

从Uri到InputSteam再到byte[]

在学okhttp post上传图片文件的时候，因为读取不了文件，所以File对象无法生成，导致RequestBody fileBody = RequestBody.create(mediaType,content);方法中，content无法成为file对象，如何解决上传图片的问题？

查看create方法的传参：

发现可以用byte[]数组进行上传，ok那就换一种方式——从Uri到InputSteam到byte[]

我编写了一个工具类，其中的方法可以看看注释：

import ...;

public class QStorageUtils {
    // 从图片路径转为Uri
    public static Uri imagePath2Uri(Context context, String path) {
        Cursor cursor = null;
        try {
            cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                    new String[]{MediaStore.Images.Media._ID}, MediaStore.Images.Media.DATA + "=? ",
                    new String[]{path}, null);
            if (cursor != null && cursor.moveToFirst()) {
                @SuppressLint("Range") int id = cursor.getInt(cursor.getColumnIndex(MediaStore.MediaColumns._ID));
                Uri baseUri = Uri.parse("content://media/external/images/media");
                return Uri.withAppendedPath(baseUri, "" + id);
            } else {
                // 如果图片不在手机的共享图片数据库，就先把它插入。
                if (new File(path).exists()) {
                    ContentValues values = new ContentValues();
                    values.put(MediaStore.Images.Media.DATA, path);
                    return context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
                } else {
                    return null;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            closeSteam(cursor);
        }
        return null;
    }

    // Uri转为Bytes数组
    public static byte[] Uri2Bytes(Context context, Uri uri) {
        InputStream is = null;
        ByteArrayOutputStream baos = null;
        try {
            baos = new ByteArrayOutputStream();
            is = context.getContentResolver().openInputStream(uri);
            byte[] buf = new byte[1024];
            int len = 0;
            String content = null;
            while ((len=is.read(buf)) != -1) {
                baos.write(buf,0,len);
            }
            return baos.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            closeSteam(is);
            closeSteam(baos);
        }
        return new byte[0];
    }

    // 关闭流
    public static void closeSteam(Closeable stream) {
        try {
            if (stream != null) {
                stream.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

okhttp使用post上传文件的方法如下：

@SuppressLint("Range")
private void btnDoUploadFile() {
    OkHttpClient client = new OkHttpClient.Builder()
        .connectTimeout(10000,TimeUnit.MILLISECONDS)
        .build();
    Uri imageContentUri = QStorageUtils.imagePath2Uri(this, "/storage/emulated/0/Download/1195405.jpg");
    Log.d(TAG,"pic uri --> " + imageContentUri);
    byte[] content = QStorageUtils.Uri2Bytes(this,imageContentUri);
    MediaType mediaType = MediaType.parse("image/jpeg");
    RequestBody fileBody = RequestBody.create(mediaType,content);
    RequestBody requestBody = new MultipartBody.Builder()
        .addFormDataPart("file","1.jpg",fileBody)
        .build();

    Request request = new Request.Builder()
        .url(BASE_URL + "file/upload")
        .post(requestBody)
        .build();

    Call task = client.newCall(request);
    task.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            Log.d(TAG,"onFailure --> " + e.toString());
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            if (response.isSuccessful()) {
                Log.d(TAG,"response code --> " + response.code());
                ResponseBody body = response.body();
                assert body != null;
                Log.d(TAG,"response body --> " + body.string());
            }
        }
    });
}