本文实例为大家分享了Java实现按比例缩小图片的具体代码,供大家参考,具体内容如下
使用spring注解上传文件@RequestParam(value="", required=true),required为true时不能传入空值,为false时反之;UploadFile.getOriginalFilename()获取上传的文件的文件名;System.nanoTime()返回当前时间的纳秒,用做文件名;FileUtils.writeByteArrayToFile()上传文件到本地目录;使用BufferedImage将图片加载到内存中,然后对图片进行修改如大小变换、图片变灰、设置透明等。
效果图:
HTML:
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< div class = "form-group" > < label class = "col-lg-1 col-md-1 col-sm-2 col-xs-2 label-size" >< span class = "c-red" >*</ span >头像:</ label > < div class = "col-lg-4 col-md-4 col-sm-4 col-xs-4 img-padding-zero" > < div > < span id = "Upload_ph" class = "img-hide" > < input type = "file" title = "" id = "UploadFile" name = "UploadFile" multiple = "" class = "img-input" > </ span > < span > < img alt = "" src = "${ctx}/UserManages/reveal_photo.do?file=tree.png" > < a class = "a-word" style = "cursor:pointer;" >上传图片</ a > < a id = "showApellation" class = "a-word" style = "font-size:12px;" ></ a > </ span > </ div > < div > < img src = "${ctx}/UserManages/reveal_photo.do?file=noImg.png" class = "img-padding" width = "198" height = "198" alt = "" id = "imgOperPhoto1" onload = "AutoResizeImage(198, 198, this)" title = "用于头像显示" > < img src = "${ctx}/UserManages/reveal_photo.do?file=noImg_tab.png" class = "img-padding" width = "28" height = "40" alt = "" id = "imgOperPhoto3" title = "用于列表显示" > </ div > </ div > </ div > |
form表单提交到java:
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@SuppressWarnings ( "unused" ) @RequestMapping (value= "/IntOpers" ) private void IntOper( @RequestParam (value= "UploadFile" , required= true ) MultipartFile UploadFile, PrintWriter pw, HttpServletRequest request) throws IOException { String StrReturn = "error" , FileName = "" , ext = "" ; long time = 0 ; if (!UploadFile.isEmpty()) { if (UploadFile != null ) { String fullName = UploadFile.getOriginalFilename(); ext = fullName.substring(fullName.lastIndexOf( "." )); //获取扩展名称 time = System.nanoTime(); FileName = time + ext; //设置文件保存的名称 //原图 String upDir = "F:/java/upload-ssm" ; //文件上传路径 FileUtils.writeByteArrayToFile( new File(upDir, FileName), UploadFile.getBytes()); //缩小图片 Image srcFile = ImageIO.read( new File(upDir + "/" + FileName)); BufferedImage tag = new BufferedImage( 28 , 40 , BufferedImage.TYPE_INT_RGB); tag.getGraphics().drawImage(srcFile, 0 , 0 , 28 , 40 , null ); String FileName_tab = time + "_tab" + ext; //设置文件保存的名称 FileOutputStream out = new FileOutputStream(upDir + "/" + FileName_tab); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(tag); jep.setQuality(1f, true ); encoder.encode(tag, jep); out.close(); StrReturn = "success" ; } } pw.write(StrReturn); } |
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/ljylyz/article/details/87892709