package com.fel.util;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import sun.misc.BASE64Encoder;
import javax.imageio.*;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.output.DeferredFileOutputStream;
import org.apache.log4j.Logger;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class ImagePreview {
private final static Logger LOGGER = Logger.getLogger(ImagePreview.class);
public ImagePreview(){
}
public String ProcessRequest(HttpServletRequest request) throws ServletException, IOException{
BASE64Encoder encoder = new BASE64Encoder();
byte[] bs = null;
long filesize = 0;
DiskFileItemFactory factory = new DiskFileItemFactory();
int width = 0;
int height = 0;
InputStream inputStream = null;
ByteArrayOutputStream op = null;
DeferredFileOutputStream dfo = null;
try{
factory.setSizeThreshold(4096);// 设置缓冲,这个值决定了是fileinputstream还是bytearrayinputstream
//factory.setRepository(new File("d:\\temp"));//设置临时存放目录,默认是new File(System.getProperty("java.io.tmpdir"))
ServletFileUpload sfileUpLoad = new ServletFileUpload(factory);
sfileUpLoad.setSizeMax(10*1024*1024);//10M
List items = sfileUpLoad.parseRequest(request);
Iterator it = items.iterator();
//暂时只考虑单文件
while(it.hasNext()){
FileItem fileItem = (FileItem)it.next();
if(!fileItem.isFormField()){
inputStream = fileItem.getInputStream();
filesize = fileItem.getSize();
bs = new byte[(int)filesize];
}else{
if (fileItem.getFieldName().equals("width")) {
dfo = (DeferredFileOutputStream) fileItem.getOutputStream();
width = Integer.parseInt(new String(dfo.getData()));
}
if (fileItem.getFieldName().equals("height")) {
dfo = (DeferredFileOutputStream) fileItem.getOutputStream();
height = Integer.parseInt(new String(dfo.getData()));
}
}
}
op = ResizeImg(inputStream, width, height);
bs = op.toByteArray();
String imgpath = "data:image/jpeg;base64," ;
String img = encoder.encode(bs);
imgpath += img;
return imgpath;
}catch (FileUploadException e) {
e.printStackTrace();
LOGGER.error(e);
} catch (IOException e) {
e.printStackTrace();
LOGGER.error(e);
}finally{
if(dfo != null){
dfo.close();
}
if(inputStream != null){
inputStream.close();
}
if(op!= null){
op.close();
}
}
//blankimage
return "data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==";
}
//只对jpg缩放
public ByteArrayOutputStream ResizeImg(InputStream inputStream,int maxWidth,int maxHeight) throws IOException{
BufferedImage bufferimage = ImageIO.read(inputStream);
int curWidth = bufferimage.getWidth();
int curHeight = bufferimage.getHeight();
// double desiredRatio = Math.min((double)(maxWidth)/(double)curWidth,(double)maxHeight/(double)curHeight);
// curWidth = (int) (curWidth*desiredRatio);
// curHeight = (int)(curHeight*desiredRatio);
double ratio = 0;
Image itemp = bufferimage.getScaledInstance(maxWidth, maxHeight, bufferimage.SCALE_SMOOTH);
// 计算比例
if ((bufferimage.getHeight() > maxHeight) || (bufferimage.getWidth() > maxWidth)) {
if (bufferimage.getHeight() > bufferimage.getWidth()) {
ratio = (new Integer(maxHeight)).doubleValue() / bufferimage.getHeight();
} else {
ratio = (new Integer(maxWidth)).doubleValue() / bufferimage.getWidth();
}
AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);
itemp = op.filter(bufferimage, null);
}
BufferedImage bufftmp = new BufferedImage(curWidth,curHeight,BufferedImage.TYPE_INT_RGB);
Graphics2D g2D = bufftmp.createGraphics();
g2D.setColor(Color.white);
g2D.fillRect(0, 0, curWidth, curHeight);
// g2D.drawImage(bufferimage, null, 0, 0);
if (maxWidth == itemp.getWidth(null))
g2D.drawImage(itemp, 0, (maxHeight - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);
else
g2D.drawImage(itemp, (maxWidth - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);
g2D.dispose();
// itemp = bufftmp;
ByteArrayOutputStream op = new ByteArrayOutputStream();
JPEGImageEncoder imageEncoder = JPEGCodec.createJPEGEncoder(op);
imageEncoder.encode((BufferedImage)itemp);
return op;
}
}
上传图片预览java代码
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2010-07-09
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收藏 13KB RAR 举报 
ImagePreview_jsp.rar （7个子文件） 
WebRoot page 
.tmp_ImagePreviewd.htm.82170~ 4KB ImagePreviewd.htm 4KB viewImg.jsp 196B resources js imgPreview QuickUpload.js 5KB ImagePreviewd.js 6KB CJL.0.1.min.js 5KB src com fel util ImagePreview.java 5KB
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