Android 如何将图像从其 URL 传输到 SD 卡？
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原文地址: http://stackoverflow.com/questions/3296850/
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How do I transfer an image from its URL to the SD card?
提问by Jameskittu
How can I save an images to the SD card that I retrieve from the image's URL?
如何将图像保存到从图像 URL 检索的 SD 卡中？
回答by Akusete
First you must make sure your application has permission to write to the sdcard. To do this you need to add the uses permission write external storagein your applications manifest file. See Setting Android Permissions
首先，您必须确保您的应用程序具有写入 SD 卡的权限。为此，您需要在应用程序清单文件中添加使用权限写入外部存储。请参阅设置 Android 权限
Then you can you can download the URL to a file on the sdcard. A simple way is:
然后，您可以将 URL 下载到 sdcard 上的文件。一个简单的方法是：
URL url = new URL ("file://some/path/anImage.png");
InputStream input = url.openStream();
try {
//The sdcard directory e.g. '/sdcard' can be used directly, or
//more safely abstracted with getExternalStorageDirectory()
File storagePath = Environment.getExternalStorageDirectory();
OutputStream output = new FileOutputStream (new File(storagePath,"myImage.png"));
try {
byte[] buffer = new byte[aReasonableSize];
int bytesRead = 0;
while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0) {
output.write(buffer, 0, bytesRead);
}
} finally {
output.close();
}
} finally {
input.close();
}
EDIT :Put permission in manifest
编辑：将权限放在清单中
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
回答by ognian
An excellent example can be found in the latest poston Android developer's blog:
一个很好的例子可以在 Android 开发者博客的最新文章中找到：
static Bitmap downloadBitmap(String url) {
final AndroidHttpClient client = AndroidHttpClient.newInstance("Android");
final HttpGet getRequest = new HttpGet(url);
try {
HttpResponse response = client.execute(getRequest);
final int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
Log.w("ImageDownloader", "Error " + statusCode +
" while retrieving bitmap from " + url);
return null;
}
final HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream inputStream = null;
try {
inputStream = entity.getContent();
final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
} finally {
if (inputStream != null) {
inputStream.close();
}
entity.consumeContent();
}
}
} catch (Exception e) {
// Could provide a more explicit error message for IOException or
// IllegalStateException
getRequest.abort();
Log.w("ImageDownloader", "Error while retrieving bitmap from " + url,
e.toString());
} finally {
if (client != null) {
client.close();
}
}
return null;
}
