【分享】uploader上传，java servlet 接收数据代码

       ServletFileUpload servletFileUpload = new ServletFileUpload();  
        FileItemIterator fileItemIterator = servletFileUpload.getItemIterator(request);  

        byte[] imageDatas = null;  
        String imageName  = null;  
        String imgFormatName = null;  
        if (fileItemIterator.hasNext())  
        {  

            FileItemStream fileStream = fileItemIterator.next();  
            imageName = fileStream.getName();  

            if (imageName == null || imageName.trim().length() == 0)  
            {  
                throw new Exception("文件名称为空");  
            }  

            imageName = imageName.toLowerCase();  
            if (imageName.endsWith("jpg") || imageName.endsWith("jpeg"))  
            {  
                imgFormatName = "jpg";  
            }  
            else if (imageName.endsWith("png"))  
            {  
                imgFormatName = "png";  
            }  
            else if (imageName.endsWith("gif"))  
            {  
                imgFormatName = "gif";  
            }  
            else  
            {  
                throw new Exception("只支持:jpg、png、gif三种图片");  
            }  

            ByteArrayOutputStream baos = new ByteArrayOutputStream();  

            InputStream inputStream = null;  

            try {  
                inputStream = fileStream.openStream();  

                BufferedImage bufferedImage = ImageIO.read(inputStream);  

                int width = bufferedImage.getWidth();  
                int height = bufferedImage.getHeight();  

                BufferedImage needSavedImage = bufferedImage;  
                if (width > 600) {  
                    needSavedImage = org.imgscalr.Scalr.resize(bufferedImage, Method.SPEED, 600, Float.valueOf(height * (600.0f/width)).intValue(), org.imgscalr.Scalr.OP_BRIGHTER);  
                }  
                else if (height > 600) {  
                    needSavedImage = org.imgscalr.Scalr.resize(bufferedImage, Method.SPEED, Float.valueOf(width * (600.0f/height)).intValue(), 600, org.imgscalr.Scalr.OP_BRIGHTER);  
                }  

                ImageIO.write(needSavedImage, imgFormatName, baos);  

                imageDatas = baos.toByteArray();  
            }  
            catch(Exception e)  
            {  
                Logger.error(e.getMessage(), e);  
            }  
            finally   
            {  
                if (inputStream != null)  
                {  
                    try {  
                        inputStream.close();  
                    }  
                    catch(Exception e)  
                    {  
                        Logger.error(e.getMessage(), e);  
                    }  
                }  
            }  
        }  

这是一个简单的例子：
1） 图片格式只是通过扩展名来做了个简单地过滤
2） 图片的压缩，逻辑简单，够用了，更复杂的逻辑，自个儿补充就行
3）用到了两个库：apache的common upload 以及图片工具类库 org.imgscalr.Scalr （github上有源码，自个儿搜）