/**
* Loads an image from the supplied input stream. Supports formats supported by {@link ImageIO}
* but not {@link FastImageIO}.
*/
protected static BufferedImage loadImage(InputStream iis) throws IOException {
BufferedImage image;
if (iis instanceof ImageInputStream) {
image = ImageIO.read(iis);
} else {
// if we don't already have an image input stream, create a memory cache image input
// stream to avoid causing freakout if we're used in a sandbox because ImageIO
// otherwise use FileCacheImageInputStream which tries to create a temp file
MemoryCacheImageInputStream mciis = new MemoryCacheImageInputStream(iis);
image = ImageIO.read(mciis);
try {
// this doesn't close the underlying stream
mciis.close();
} catch (IOException ioe) {
// ImageInputStreamImpl.close() throws an IOException if it's already closed;
// there's no way to find out if it's already closed or not, so we have to check
// the exception message to determine if this is actually warning worthy
if (!"closed".equals(ioe.getMessage())) {
log.warning("Failure closing image input '" + iis + "'.", ioe);
}
}
}
// finally close our input stream
StreamUtil.close(iis);
return image;
}
/**
* 计算文件的contextType
*
* @param fileName
* @param mapObj
* @return
*/
private static String getContentType(String fileName, byte[] mapObj) {
String contextType = null;
if (fileName != null) {
contextType = new MimetypesFileTypeMap().getContentType(fileName);
}
if (contextType != null) {
return contextType;
}
ByteArrayInputStream bais = null;
MemoryCacheImageInputStream mcis = null;
try {
bais = new ByteArrayInputStream(mapObj);
mcis = new MemoryCacheImageInputStream(bais);
Iterator<ImageReader> itr = ImageIO.getImageReaders(mcis);
while (itr.hasNext()) {
ImageReader reader = itr.next();
if (reader instanceof GIFImageReader) {
contextType = "image/gif";
} else if (reader instanceof JPEGImageReader) {
contextType = "image/jpeg";
} else if (reader instanceof PNGImageReader) {
contextType = "image/png";
} else if (reader instanceof BMPImageReader) {
contextType = "application/x-bmp";
}
}
} finally {
if (bais != null) {
try {
bais.close();
} catch (IOException ioe) {
}
}
if (mcis != null) {
try {
mcis.close();
} catch (IOException ioe) {
}
}
}
return contextType;
}