jsp上传图片并产生缩略图的代码

jsp上传图片并产生缩略图的代码

jsp产生缩略图：
//读入刚才上传的文件
java.io.File file = new java.io.File(saveurl);
//新的缩略图保存地址
String newurl=request.getRealPath("/")+url+"min_"+filename+"."+ext;
//构造Image对象 Image src = javax.imageio.ImageIO.read(file);
float tagsize=200;
int old_w=src.getWidth(null); //得到源图宽
int old_h=src.getHeight(null); //得到源图长
int new_w=0;
int new_h=0;
int temps教程ize;
float tempdouble;
if(old_w>old_h){
tempdouble=old_w/tagsize;
}else{
tempdouble=old_h/tagsize;
}
new_w=Math.round(old_w/tempdouble);
new_h=Math.round(old_h/tempdouble);//计算新图长宽
BufferedImage tag = new BufferedImage(new_w,new_h,BufferedImage.TYPE_INT_RGB);
tag.getGraphics().drawImage(src,0,0,new_w,new_h,null); //绘制缩小后的图
FileOutputStream newimage=new FileOutputStream(newurl); //输出到文件流
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(newimage);
encoder.encode(tag); //近JPEG编码

newimage.close();

我有个包，可以在tomcat中运行，不过没有 source code.. 要的找我要。 已发送。。

import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; import org.apache.commons.io.FileUtils; public class ImageUtil { private int width; private int height; private int zoomWidth; private int zoomHeight; private File destFile; private BufferedImage srcBufferImage; public static void resizeFix(File srcFile, File destFile, int width, int height) throws IOException { new ImageUtil(srcFile, destFile, width, height); } public static void resizeFix(BufferedImage bufImg, File destFile, int width, int height) throws IOException { new ImageUtil(bufImg, destFile, width, height); } protected ImageUtil(File srcFile, File destFile, int zoomWidth, int zoomHeight) throws IOException { this.destFile = destFile; this.zoomWidth = zoomWidth; this.zoomHeight = zoomHeight; this.srcBufferImage = javax.imageio.ImageIO.read(srcFile); this.width = this.srcBufferImage.getWidth(); this.height = this.srcBufferImage.getHeight(); if (width <= zoomWidth && height <= zoomHeight) { FileUtils.copyFile(srcFile, destFile); } else { resizeFix(); } } protected ImageUtil(BufferedImage srcBufferImage, File destFile, int zoomWidth, int zoomHeight) throws IOException { this.destFile = destFile; this.zoomWidth = zoomWidth; this.zoomHeight = zoomHeight; this.srcBufferImage = srcBufferImage; this.width = this.srcBufferImage.getWidth(); this.height = this.srcBufferImage.getHeight(); resizeFix(); } protected void resizeFix() throws IOException { if (width <= zoomWidth && height <= zoomHeight) { resize(width, height); } else if ((float) width / height > (float) zoomWidth / zoomHeight) { resize(zoomWidth, Math.round((float) zoomWidth * height / width)); } else { resize(Math.round((float) zoomHeight * width / height), zoomHeight); } } private void resize(int w, int h) throws IOException { BufferedImage imgBuf = scaleImage(w, h); File parent = destFile.getParentFile(); if (!parent.exists()) { parent.mkdirs(); } ImageIO.write(imgBuf, "jpeg", destFile); } private BufferedImage scaleImage(int outWidth, int outHeight) { int[] rgbArray = srcBufferImage.getRGB(0, 0, width, height, null, 0, width); BufferedImage pbFinalOut = new BufferedImage(outWidth, outHeight, BufferedImage.TYPE_INT_RGB); double hScale = ((double) width) / ((double) outWidth);// 宽缩小的倍数 double vScale = ((double) height) / ((double) outHeight);// 高缩小的倍数 int winX0, winY0, winX1, winY1; int valueRGB = 0; long R, G, B; int x, y, i, j; int n; for (y = 0; y < outHeight; y++) { winY0 = (int) (y * vScale + 0.5);// 得到原图高的Y坐标 if (winY0 < 0) { winY0 = 0; } winY1 = (int) (winY0 + vScale + 0.5); if (winY1 > height) { winY1 = height; } for (x = 0; x < outWidth; x++) { winX0 = (int) (x * hScale + 0.5); if (winX0 < 0) { winX0 = 0; } winX1 = (int) (winX0 + hScale + 0.5); if (winX1 > width) { winX1 = width; } R = 0; G = 0; B = 0; for (i = winX0; i < winX1; i++) { for (j = winY0; j < winY1; j++) { valueRGB = rgbArray[width * j + i]; R += getRedValue(valueRGB); G += getGreenValue(valueRGB); B += getBlueValue(valueRGB); } } n = (winX1 - winX0) * (winY1 - winY0); R = (int) (((double) R) / n + 0.5); G = (int) (((double) G) / n + 0.5); B = (int) (((double) B) / n + 0.5); valueRGB = comRGB(clip((int) R), clip((int) G), clip((int) B)); pbFinalOut.setRGB(x, y, valueRGB); } } return pbFinalOut; } private int clip(int x) { if (x < 0) return 0; if (x > 255) return 255; return x; } private int getRedValue(int rgbValue) { int temp = rgbValue & 0x00ff0000; return temp >> 16; } private int getGreenValue(int rgbValue) { int temp = rgbValue & 0x0000ff00; return temp >> 8; } private int getBlueValue(int rgbValue) { return rgbValue & 0x000000ff; } private int comRGB(int redValue, int greenValue, int blueValue) { return (redValue << 16) + (greenValue << 8) + blueValue; } public static void main(String[] args) throws IOException { long start = System.currentTimeMillis(); ImageUtil.resizeFix(new File("d:/04.jpg"), new File("d:/big-n.jpg"), 400, 400); long end = System.currentTimeMillis(); System.out.println("success:" + (end - start)); } } 依赖commons-io.jar