java 压缩图片 实例

public class ImageSizer {
public static final MediaTracker tracker = new MediaTracker(new Component() {
private static final long serialVersionUID = 1234162663955668507L;
});
/**
* 图片压缩
*
* @param originalFile 原图像
* @param resizedFile 压缩后的图像
* @param width 图像宽
* @param format 图片格式 jpg, png, gif(非动画)
* @throws IOException
*/
public static void resize(File originalFile, File resizedFile, int width, String format) throws IOException {
if (format != null && "gif".equals(format.toLowerCase())) {
resize(originalFile, resizedFile, width, 1);
return;
}
FileInputStream fis = new FileInputStream(originalFile);
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
int readLength = -1;
int bufferSize = 1024;
byte bytes[] = new byte[bufferSize];
while ((readLength = fis.read(bytes, 0, bufferSize)) != -1) {
byteStream.write(bytes, 0, readLength);
}
byte[] in = byteStream.toByteArray();
fis.close();
byteStream.close();
Image inputImage = Toolkit.getDefaultToolkit().createImage(in);
waitForImage(inputImage);
int imageWidth = inputImage.getWidth(null);
if (imageWidth < 1) {
throw new IllegalArgumentException("image width " + imageWidth + " is out of range");
}
int imageHeight = inputImage.getHeight(null);
if (imageHeight < 1) {
throw new IllegalArgumentException("image height " + imageHeight + " is out of range");
}
// Create output image.
int height = -1;
double scaleW = (double) imageWidth / (double) width;
double scaleY = (double) imageHeight / (double) height;
if (scaleW >= 0 && s