java.net.URL将流读取到byte []

不能保证您提供的内容长度实际上是正确的。尝试类似以下的方法：

ByteArrayOutputStream baos = new ByteArrayOutputStream();InputStream is = null;try {  is = url.openStream ();  byte[] byteChunk = new byte[4096]; // Or whatever size you want to read in at a time.  int n;  while ( (n = is.read(byteChunk)) > 0 ) {    baos.write(byteChunk, 0, n);  }}catch (IOException e) {  System.err.printf ("Failed while reading bytes from %s: %s", url.toExternalForm(), e.getMessage());  e.printStackTrace ();  // Perform any other exception handling that's appropriate.}finally {  if (is != null) { is.close(); }}

然后，您将获得图像数据

baos

baos.toByteArray()

这段代码未经测试（我只是在答案框中写了它），但是它与我认为的要求相当接近。