重用的InputStream时BitmapFactory.de codeStream（流空，期权） [英] Reuse InputStream when BitmapFactory.decodeStream(stream, null, options)

问题描述

 的InputStream流=新的URL（键）.openStream（）;BitmapFactory.Options选项=新BitmapFactory.Options（）;
options.inJustDe codeBounds = TRUE;BitmapFactory.de codeStream（流空，期权）;options.inSampleSize = calculateInSampleSize（选项，reqWidth，
            reqHeight）;
options.inJustDe codeBounds = FALSE;/ *我需要在这里再次重用流，德code流。 * /BMP位图= BitmapFactory.de codeStream（流空，期权）;stream.close（）;返回BMP;
 

解决方案

您可以随时刚刚从URL重新打开流

 的InputStream流=新的URL（键）.openStream（）;
 

或者我们像番石榴（字节流）充分阅读的InputStream 并将所得的字节分配到一个库 ByteArrayInputStream的

 的InputStream流=新的URL（键）.openStream（）;
ByteArrayOutputStream出=新ByteArrayOutputStream（）;
ByteStreams.copy（流出来）;
ByteArrayInputStream的在=新ByteArrayInputStream进行（out.toByteArray（））;//使用一次
in.reset（）;
//再次使用它
 

小心，如果你的code调用标记（）在流。如果出现这种情况，而不仅仅是创建一个新的 ByteArrayInputStream的从 ByteArrayOutputStream 出的字节数。 toByteArray（）。

InputStream stream = new URL(key).openStream();

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;

BitmapFactory.decodeStream(stream, null, options);

options.inSampleSize = calculateInSampleSize(options, reqWidth,
            reqHeight);
options.inJustDecodeBounds = false;

/* i need reuse stream here, for decode stream again. */

Bitmap bmp = BitmapFactory.decodeStream(stream, null, options);

stream.close();

return bmp;

解决方案

You can always just reopen the stream from the URL

InputStream stream = new URL(key).openStream();

Or us a library like Guava (ByteStreams) to fully read the InputStream and assign the resulting bytes into a ByteArrayInputStream

InputStream stream = new URL(key).openStream();
ByteArrayOutputStream out = new ByteArrayOutputStream();
ByteStreams.copy(stream, out);
ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());

// use it once
in.reset();
// use it again

Careful if your code calls mark() on the stream. If that happens, instead just create a new ByteArrayInputStream with the bytes from the ByteArrayOutputStream out.toByteArray().

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