Question

在我的Android应用程序中，我想将图像存储到外部存储。我有这段代码：

package async;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import http.Network;
import interfaces.ImageDownloader;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.widget.ImageView;

public class Async_image_task extends AsyncTask<String, Void, Bitmap> {

    ImageDownloader callerContext;
    ImageView calledImageView;
    String link;

    public Async_image_task(ImageView calledImageView, String link) {
        this.callerContext = (ImageDownloader)calledImageView.getContext();
        this.calledImageView = calledImageView;
        this.link = link;
        execute(link);
    }

    @Override
    protected Bitmap doInBackground(String... params) {
        Bitmap bitmap = Network.DownloadImage((Context) callerContext, params[0]);

        if (bitmap != null) {
            try {
                String[] segments = link.split("/");
                int len = segments.length;

                String path = Environment.getExternalStorageDirectory().getAbsolutePath();
                String imgpath = segments[len-6] + "/" + segments[len-2] + "/" + segments[len-1];

                File file = new File(path, imgpath);
                file.getParentFile().mkdirs();

                String abs = file.getAbsolutePath();

                OutputStream fOut = new FileOutputStream(file);
                bitmap.compress(Bitmap.CompressFormat.PNG, 100, fOut);

                fOut.flush();
                fOut.close();

                MediaStore.Images.Media.insertImage(((Activity)callerContext).getContentResolver(),abs,file.getName(),file.getName());
            } catch (Exception e) {
                Log.d("IMAGE_ERROR", e.getMessage());
            }
        }

        return bitmap;
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        callerContext.ImageCallback(bitmap, calledImageView);
    }
}

在清单中我有这个许可：

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

但是当它尝试执行OutputStream fOut = new FileOutputStream(file);时，它会抛出一个找不到文件的异常....

错误：

06-18 17:48:35.573: D/IMAGE_ERROR(9316): /storage/sdcard0/arin/53/image.jpg: open failed: EACCES (Permission denied)

当我获得许可时，为什么会发生这种情况？

有人知道吗？

由于

logcat的

06-18 18:03:57.522: W/System.err(14213): java.io.FileNotFoundException: /storage/sdcard0/arin/53/image.jpg: open failed: EACCES (Permission denied)
06-18 18:03:57.532: W/System.err(14213):    at libcore.io.IoBridge.open(IoBridge.java:416)
06-18 18:03:57.532: W/System.err(14213):    at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
06-18 18:03:57.532: W/System.err(14213):    at java.io.FileOutputStream.<init>(FileOutputStream.java:128)
06-18 18:03:57.532: W/System.err(14213):    at java.io.FileOutputStream.<init>(FileOutputStream.java:117)
06-18 18:03:57.532: W/System.err(14213):    at async.Async_image_task.saveImage(Async_image_task.java:64)
06-18 18:03:57.532: W/System.err(14213):    at async.Async_image_task.doInBackground(Async_image_task.java:37)
06-18 18:03:57.532: W/System.err(14213):    at async.Async_image_task.doInBackground(Async_image_task.java:1)
06-18 18:03:57.532: W/System.err(14213):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
06-18 18:03:57.532: W/System.err(14213):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
06-18 18:03:57.532: W/System.err(14213):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-18 18:03:57.532: W/System.err(14213):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
06-18 18:03:57.532: W/System.err(14213):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
06-18 18:03:57.542: W/System.err(14213):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
06-18 18:03:57.542: W/System.err(14213):    at java.lang.Thread.run(Thread.java:856)
06-18 18:03:57.542: W/System.err(14213): Caused by: libcore.io.ErrnoException: open failed: EACCES (Permission denied)
06-18 18:03:57.542: W/System.err(14213):    at libcore.io.Posix.open(Native Method)
06-18 18:03:57.542: W/System.err(14213):    at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
06-18 18:03:57.542: W/System.err(14213):    at libcore.io.IoBridge.open(IoBridge.java:400)
06-18 18:03:57.542: W/System.err(14213):    ... 13 more

Answer 1

您尝试创建文件的目录可能不存在。在致电new FileOutputStream之前尝试此行：

file.mkdirs();

Answer 2

检查运行sdk版本是否低于lollipop或者小于此值：

 File sdcard = Environment.getExternalStorageDirectory();
            if (sdcard != null) {
                File mediaDir = new File(sdcard, "DCIM/Camera");
                if (!mediaDir.exists()) {
                    mediaDir.mkdirs();
                }

将图像保存到不在android中工作的外部存储

2 个答案: