java 图片 旋转

import java.awt.Color;
    import java.awt.Graphics2D;
    import java.awt.Transparency;
    import java.awt.geom.AffineTransform;
    import java.awt.image.AffineTransformOp;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.InputStream;

    import javax.imageio.ImageIO;
    import javax.imageio.stream.ImageOutputStream;

    public class ImageChange {

        public static InputStream rotateImg(BufferedImage image, int degree, Color bgcolor) throws IOException {

            int iw = image.getWidth();//原始图象的宽度
            int ih = image.getHeight();//原始图象的高度
            int w = 0;
            int h = 0;
            int x = 0;
            int y = 0;
            degree = degree % 360;
            if (degree < 0)
                degree = 360 + degree;//将角度转换到0-360度之间
            double ang = Math.toRadians(degree);//将角度转为弧度

            /**
             *确定旋转后的图象的高度和宽度
             */

            if (degree == 180 || degree == 0 || degree == 360) {
                w = iw;
                h = ih;
            } else if (degree == 90 || degree == 270) {
                w = ih;
                h = iw;
            } else {
                //int d = iw + ih;
                //w = (int) (d * Math.abs(Math.cos(ang)));
                  //h = (int) (d * Math.abs(Math.sin(ang)));
                double cosVal = Math.abs(Math.cos(ang));
                double sinVal = Math.abs(Math.sin(ang));
                w = (int) (sinVal*ih) + (int) (cosVal*iw);
                h = (int) (sinVal*iw) + (int) (cosVal*ih);
            }

            x = (w / 2) - (iw / 2);//确定原点坐标
            y = (h / 2) - (ih / 2);
            BufferedImage rotatedImage = new BufferedImage(w, h, image.getType());
            Graphics2D gs = (Graphics2D)rotatedImage.getGraphics();
            if(bgcolor==null){
                rotatedImage = gs.getDeviceConfiguration().createCompatibleImage(w, h, Transparency.TRANSLUCENT);
            }else{
                gs.setColor(bgcolor);
                gs.fillRect(0, 0, w, h);//以给定颜色绘制旋转后图片的背景
            }

            AffineTransform at = new AffineTransform();
            at.rotate(ang, w / 2, h / 2);//旋转图象
            at.translate(x, y);
            AffineTransformOp op = new AffineTransformOp(at, AffineTransformOp.TYPE_BICUBIC);
            op.filter(image, rotatedImage);
            image = rotatedImage;

            ByteArrayOutputStream byteOut= new ByteArrayOutputStream();
            ImageOutputStream iamgeOut = ImageIO.createImageOutputStream(byteOut);

            ImageIO.write(image, "png", iamgeOut);
            InputStream inputStream = new ByteArrayInputStream(byteOut.toByteArray());

            return inputStream;
        }


    }