Question

我正在尝试使用AsyncHttpClient library by loopj从网址下载图片资源，我不知道为什么我无法将其保存到内部存储空间。我的问题是，在运行下面的代码时，我没有在内部存储中看到任何图像文件，但是在日志或编译时我没有看到任何错误。以下两个Toast语句都有效。这是我正在使用的代码。

代码：

String[] allowedTypes = new String[] { "image/png" };
    AsyncHttpClient client = new AsyncHttpClient();
    client.get("http://example.com/dock.png",
            new BinaryHttpResponseHandler(allowedTypes) {
                @Override
                public void onSuccess(int i, Header[] headers, byte[] bytes) {

                    Toast.makeText(getApplicationContext(),"Successful in finding file",Toast.LENGTH_SHORT).show();
                    try {
                        Toast.makeText(getApplicationContext(),"Success",Toast.LENGTH_SHORT).show();
                        FileOutputStream f = new FileOutputStream((new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)   + File.separator + "imgdwo.png")));
                        f.write(bytes); //your bytes
                        f.close();
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onFailure(int i, Header[] headers, byte[] bytes, Throwable throwable) {

                }


    });

更新：我更改了内部存储器上的硬编码位置，但这并没有解决问题。 logcat如下：

 java.io.FileNotFoundException: /storage/emulated/0/Pictures: open failed: EISDIR (Is a directory)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at libcore.io.IoBridge.open(IoBridge.java:416)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at java.io.FileOutputStream.<init>(FileOutputStream.java:128)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at java.io.FileOutputStream.<init>(FileOutputStream.java:117)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at com.example.abhishek.asynchttpclient.AsyncActivity$1.onSuccess(AsyncActivity.java:41)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:311)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at   com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:138)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:99)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at android.os.Looper.loop(Looper.java:137)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5293)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:511)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ Caused by: libcore.io.ErrnoException: open failed: EISDIR (Is a directory)
 06-29 09:07:28.721  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at libcore.io.Posix.open(Native Method)
 06-29 09:07:28.726  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
 06-29 09:07:28.726  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ at libcore.io.IoBridge.open(IoBridge.java:400)
 06-29 09:07:28.726  17675-17675/com.example.abhishek.asynchttpclient W/System.err﹕ ... 14 more

Answer 1

需要注意的一点，

您必须确保没有以前已存在的同名目录。在创建FileOutputStream之前尝试删除目录。
使用new FileAsyncHttpResponseHandler(Context)构造函数，它会自动在您应用的缓存目录中创建临时文件，然后您可以移动文件，重命名，修改内容或删除它。

Answer 2

使用此代码创建目录（如果不存在）并在之后创建文件。

                        Bitmap mIcon;
                        File dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
if (!dir.exists()) {
                    //noinspection ResultOfMethodCallIgnored
                    dir.mkdir();
                }
String fname = "myimage.png";
File myimage =  new File(dir, fname);
                        try {
                        InputStream in = new java.net.URL(imageurl).openStream();
                        mIcon = BitmapFactory.decodeStream(in);

                        try {
                            FileOutputStream out = new FileOutputStream(myimage);
                            mIcon.compress(
                                    Bitmap.CompressFormat.JPEG,
                                    100, out);
                            out.flush();
                            out.close();
                            return myimage;

                        } catch (FileNotFoundException e) {
                            return null;
                        } catch (IOException e) {
                            return null;
                        }

                    } catch (Exception e) {
                        return null;
                    }

此代码下载图像并将其保存在您想要的目录和名称中。使用它并分享任何错误。

使用Async Http Client Library进行映像下载

2 个答案: