解决方法
根据这个博文：
http://i-proving.com/2006/07/06/java-advanced-imaging/你可以使用
Java Advanced Imaging Library做你想要的.以下示例代码应为您提供一个良好的起点.这将调整图像的高度和宽度,以及图像质量.一旦您的图像具有所需的文件大小,您可以在显示图像时将其缩放到所需的像素高度和宽度.
// read in the original image from an input stream
SeekableStream s = SeekableStream.wrapInputStream(
inputStream,true);
RenderedOp image = JAI.create("stream",s);
((OpImage)image.getRendering()).setTileCache(null);
// now resize the image
float scale = newWidth / image.getWidth();
RenderedOp resizedImage = JAI.create("SubsampleAverage",image,scale,qualityHints);
// lastly,write the newly-resized image to an
// output stream,in a specific encoding
JAI.create("encode",resizedImage,outputStream,"PNG",null);
