基于jsp+servlet电子商城

package imageUpdate; import java.awt.image.BufferedImage; import java.awt.geom.AffineTransform; import java.awt.image.AffineTransformOp; import java.awt.Image; import java.io.File; import java.io.IOException; import javax.swing.Icon; import javax.swing.ImageIcon; import javax.imageio.ImageIO; public class ImageUtil { public static void main(String arg[]) { String filePath = "C:\\Users\\CYT\\Desktop\\today\\images\\error.gif"; // 图片的位置 int height=30; int width=30; Icon icon = null; try { icon = getRatioWidth(filePath,width); } catch(Exception e) { System.out.println("exception : " +e); } System.out.println(" ### " +icon); //生成新图片的位置； } /** * 按宽的比例更改图片的大小 * @param filePath 图片路径 * @param width 需要改变图片的宽度 * @return * @throws Exception */ public static Icon getRatioWidth(String filePath, int width) throws Exception{ File f = new File(filePath); BufferedImage bi = ImageIO.read(f); double wRatio = (new Integer(width)).doubleValue() / bi.getWidth(); //宽度的比例 int height = (int)(wRatio * bi.getHeight()); //图片转换后的高度 Image image = bi.getScaledInstance(width,height,Image.SCALE_SMOOTH); //设置图像的缩放大小 AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(wRatio,wRatio),null); //设置图像的缩放比例 image = op.filter(bi,null); int lastLength = filePath.lastIndexOf("."); String subFilePath = filePath.substring(0,lastLength); //得到图片输出路径 String fileType = filePath.substring(lastLength); //图片类型 String type=filePath.substring(lastLength+1); //图片类型 不包括点 File zoomFile = new File(subFilePath +"_" + fileType); Icon ret = null; try { ImageIO.write((BufferedImage)image, type, zoomFile); ret = new ImageIcon(zoomFile.getPath()); } catch (Exception e) { e.printStackTrace(); } return ret; } /** * 按高的比例更改图片大小 * @param filePath 图片路径 * @param height 需要改变图片的高度 * @return * @throws Exception */ public static Icon getRatioHeight(String filePath, int height) throws Exception{ File f = new File(filePath); BufferedImage bi = ImageIO.read(f); double hRatio = (new Integer(height)).doubleValue() / bi.getHeight(); //高度的比例 int width = (int)(hRatio * bi.getWidth()); //图片转换后的高度 Image image = bi.getScaledInstance(width,height,Image.SCALE_SMOOTH); //设置图像的缩放大小 AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(hRatio,hRatio),null); //设置图像的缩放比例 image = op.filter(bi,null); int lastLength = filePath.lastIndexOf("."); String subFilePath = filePath.substring(0,lastLength); //得到图片输出路径 String fileType = filePath.substring(lastLength); //图片类型 File zoomFile = new File(subFilePath +"_" + fileType); Icon ret = null; try { ImageIO.write((BufferedImage)image, fileType, zoomFile); ret = new ImageIcon(zoomFile.getPath()); } catch (Exception e) { e.printStackTrace(); } return ret; } /** * 按输入的任意宽高改变图片的大小 * @param filePath * @param width * @param height * @return * @throws Exception */ public static Icon getFixedIcon(String filePath, int width, int height) throws Exception{ File f = new File(filePath); BufferedImage bi = ImageIO.read(f); double wRatio = (new Integer(width)).doubleValue() / bi.getWidth(); //宽度的比例 double hRatio = (new Integer(height)).doubleValue() / bi.getHeight(); //高度的比例 Image image = bi.getScaledInstance(width,height,Image.SCALE_SMOOTH); //设置图像的缩放大小 AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(wRatio,hRatio),null); //设置图像的缩放比例 image = op.filter(bi,null); int lastLength = filePath.lastIndexOf("."); String subFilePath = filePath.substring(0,lastLength); //得到图片输出路径 String fileType = filePath.substring(lastLength); //图片类型 String type=filePath.substring(lastLength+1); //图片类型 不包括点 File zoomFile = new File(subFilePath +"_" + fileType); Icon ret = null; try { ImageIO.write((BufferedImage)image, type, zoomFile); ret = new ImageIcon(zoomFile.getPath()); } catch (Exception e) { e.printStackTrace(); } return ret; } }