1 前台jsp:文件的上传利用了iframe实现局部刷新功能。使用了apache的fileupload组件，用到的jar: commons-fileupload.jar,commons-io.jar
DiskFileItemFactory fac = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(fac);
upload.setHeaderEncoding("utf-8");
Html代码
<%@ page contentType="text/html;charset=UTF-8" %> <%@page import="com.pdcss.bmxxfb.model.*" %> <%@ include file="/commons/taglibs.jsp" %> <style> .perview {200px;background:#fff;font-size:12px; border-collapse:collapse;} .perview td, .perview th {padding:0px;border:0px;} .perview th {background-color:#f0f0f0; height:20px;} .perview a:link, .perview a:visited, .perview a:hover, .perview a:active {color:#00F;} .perview table{ 100%;border:1px solid #ccc;border-collapse:collapse;} </style> <script type="text/javascript" src="${ctx}/scripts/imgPreview/CJL.0.1.min.js"></script> <script type="text/javascript" src="${ctx}/scripts/imgPreview/QuickUpload.js"></script> <script type="text/javascript" src="${ctx}/scripts/imgPreview/ImagePreviewd.js"></script> <script type="text/javascript"> <!-- //处理文件上传后的回调，如果成功，则关闭当前窗口，刷新index function callback(flag,msg){ if(flag=='true'){ $("#pdtpNewForm").parent().parent().hide(); navTab.reload('/bmxxfb/wzxxfbpdtp/manager'); }else{ alert(msg); } } //提交之前检查各字段 function checkPdtpSubmit(){ var zzdm = $("#pdtpNewForm #zzdm"); if(zzdm.val().trim() ==""){ alert("组织代码不能为空！"); zzdm.focus(); return false; } var bmdm = $("#pdtpNewForm #bmdm"); if(bmdm.val().trim() ==""){ alert("组织代码不能为空！"); bmdm.focus(); return false; } var tpbt = $("#pdtpNewForm #tpbt"); if(tpbt.val().trim() ==""){ alert("飘动主题不能为空！"); tpbt.focus(); return false; } var tplj = $("#pdtpNewForm #tplj"); if(tplj.val().trim() ==""){ alert("链接地址不能为空！"); tplj.focus(); return false; } var imgFile = $("#pdtpNewForm #imgFile"); if(imgFile.val().trim() ==""){ alert("图片不能为空"); imgFile.focus(); return false; } var extStart=imgFile.val().lastIndexOf("."); var ext=imgFile.val().substring(extStart,imgFile.val().length).toLowerCase(); if(ext!=".bmp"&&ext!=".png"&&ext!=".gif"&&ext!=".jpg"&&ext!=".jpeg"){ alert("图片限于bmp,png,gif,jpeg,jpg格式"); imgFile.focus(); return false; } var regl=/^+?[1-9][0-9]*$/; var kd = $("#pdtpNewForm #kd"); if(!regl.test(kd.val())){ alert("宽度应该为正整数！"); kd.focus(); return false; } if(parseInt(kd.val())>225){ alert("宽度不能超过225！"); kd.focus(); return false; } var gd = $("#pdtpNewForm #gd"); if(!regl.test(gd.val())){ alert("宽度应该为正整数！"); gd.focus(); return false; } if(parseInt(gd.val())>200){ alert("高度不能超过200！"); gd.focus(); return false; } return true; } function changeValue(flag){ if(flag=='kd'){ $("#pdtpNewForm #kd").val($("#kd_tem").val()); } if(flag == 'gd'){ $("#pdtpNewForm #gd").val($("#gd_tem").val()); } } var ip = new ImagePreview( $$("imgFile"), $$("idImg"),{ maxWidth: 225, maxHeight: 170, action: "viewImg.jsp" }); ip.img.src = ImagePreview.TRANSPARENT; ip.file.onchange = function(){ var imgFile = $("#pdtpNewForm #imgFile"); if(imgFile.val().trim() ==""){ alert("图片不能为空"); imgFile.focus(); return false; } var extStart=imgFile.val().lastIndexOf("."); var ext=imgFile.val().substring(extStart,imgFile.val().length).toLowerCase(); if(ext!=".bmp"&&ext!=".png"&&ext!=".gif"&&ext!=".jpg"&&ext!=".jpeg"){ alert("图片限于bmp,png,gif,jpeg,jpg格式"); imgFile.focus(); return false; } ip.preview(); $("#idImg").attr("src","data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="); }; $(document).ready(function(){ $("#idImg").attr("src","data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="); }); //--> </script> <form:form method="post" action="${ctx}/wzxxfbpdtp/save" target="hidden_frame" id="pdtpNewForm" enctype="multipart/form-data" modelAttribute="wzXxfbPdtp"> <div class="pageContent" layoutH="30"> <div class="pageFormContent" align="center" style="overflow: hidden;"> <input type="hidden" id="pkid" name="pkid" value="${wzXxfbPdtp.pkid}"/> <input type="hidden" name="imgPath" id="imgPath" /> <input type="hidden" name="testH" value="testH"> <table align="center" width="500px" height="300px" border="0" cellpadding="0" cellspacing="0" style="margin-top: 10px;text-align: center;border-spacing: 10px;"> <tr> <td align="right" width="70px"> <%=WzXxfbPdtp.ALIAS_ZZDM%>: </td> <td width="120px"> <form:input path="zzdm" id="zzdm" size="25" readonly="true" value="${zzdm }" maxlength="50" /> </td> <td width="225px" rowspan="6"> <table border="0" cellpadding="0" cellspacing="0"> <tr><th bgcolor="#f0f0f0" style="line-height: 25px;"><center>预览图</center></th></tr> <tr> <td> <div style=" 225px;height: 170px;border:1px solid #99BBE8"> <table border="0" class="perview"> <tr> <td align="center"><img id="idImg"/></td> </tr> </table> </div> </td> </tr> </table> </td> </tr> <tr> <td width="70px"> <label for="bmdm"><%=WzXxfbPdtp.ALIAS_BMDM%>:</label> </td> <td width="120px"> <form:input path="bmdm" id="bmdm" size="25" readonly="true" value="${bmdm }" maxlength="50" /> </td> </tr> <tr> <td width="70px"> <label for="tpbt"><%=WzXxfbPdtp.ALIAS_TPBT%>:</label> </td> <td width="120px"> <form:input path="tpbt" id="tpbt" size="25" cssClass="required" maxlength="100" /> </td> </tr> <tr> <td width="70px"> <label for="tplj"><%=WzXxfbPdtp.ALIAS_TPLJ%>:</label> </td> <td width="120px"> <form:input path="tplj" id="tplj" size="25" cssClass="required" maxlength="1000" /> </td> </tr> <tr> <td width="70px"> 图片宽高: </td> <td width="120px"> <table> <tr> <td> <input id="kd_tem" name="kd_tem" value="160" onchange="javascript:changeValue('kd');" size="8" maxlength="4"> <input type="hidden" id="kd" name="kd" value="160"> </td> <td> 单位(px)</td> </tr> </table> </td> </tr> <tr> <td width="70px"> <label for="gd"><%=WzXxfbPdtp.ALIAS_GD%>:</label> </td> <td width="120px"> <table> <tr> <td> <input id="gd_tem" name="gd_tem" value="100" size="8" maxlength="4" onchange="javascript:changeValue('gd');"> <input type="hidden" id="gd" name="gd" value="100"> </td> <td> 单位(px)</td> </tr> </table> </td> </tr> <tr> <td colspan="2" width="190px"> <label for="sfpd"><%=WzXxfbPdtp.ALIAS_SFPD%>:</label> <label><input type="radio" name="sfpd" value="1" checked="checked">飘动</label> <label><input type="radio" name="sfpd" value="0">不飘动</label> </td> <td><font color="red">只允许上传1M内jpg,jpeg,gif,png格式图片</font></td> </tr> <tr> <td width="70px">选择图片</td> <td colspan="2"><input id="imgFile" name="imgFile" type="file" /></td> </tr> </table> </div> </div> <iframe name="hidden_frame" id="hidden_frame" src="message.html" style="display:none"></iframe> <div class="formBar"> <ul> <li> <div class="buttonActive"><div class="buttonContent"><button type="submit" onclick="return checkPdtpSubmit();">保存</button></div></div> </li> <li> <div class="button"><div class="buttonContent"><button type="button" class="close">关闭</button></div></div> </li> </ul> </div> </form:form>
2 后台Controller
import java.io.File; import java.io.PrintWriter; import java.io.UnsupportedEncodingException; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.Iterator; import java.util.List; import javacommon.base.BaseRestSpringController; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.validation.Valid; 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.springframework.beans.propertyeditors.CustomDateEditor; import org.springframework.stereotype.Controller; import org.springframework.ui.ModelMap; import org.springframework.validation.BindingResult; import org.springframework.web.bind.WebDataBinder; import org.springframework.web.bind.annotation.InitBinder; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import cn.org.rapid_framework.page.Page; import cn.org.rapid_framework.web.scope.Flash; import com.common.consts.StaticDict; /** * @author pdcss * 这里是控制层,用于编写页面跳转控制,容器变量管理,JavaBean收集传递的代码 * 严禁出现 SQL,HQL,HTML,JS,CSS代码 * 可以将其他service层注入这里,但严禁将dao层注入这里 * */ @Controller @RequestMapping("/wzxxfbpdtp") public class WzXxfbPdtpController extends BaseRestSpringController<WzXxfbPdtp,java.lang.String>{ //默认多列排序,example: username desc,createTime asc protected static final String DEFAULT_SORT_COLUMNS = ""; private WzXxfbPdtpManager wzXxfbPdtpManager; private final String LIST_ACTION = "redirect:/wzxxfbpdtp/manager"; /** * 增加setXXXX()方法,spring就可以通过autowire自动设置对象属性,注意大小写 **/ public void setWzXxfbPdtpManager(WzXxfbPdtpManager manager) { this.wzXxfbPdtpManager = manager; } /** binder用于bean属性的设置 */ @InitBinder public void initBinder(WebDataBinder binder) { binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"), true)); } /** * 增加了@ModelAttribute的方法可以在本controller方法调用前执行,可以存放一些共享变量,如枚举值,或是一些初始化操作 */ @ModelAttribute public void init(ModelMap model) { model.put("now", new java.sql.Timestamp(System.currentTimeMillis())); /** * 读入静态字典 */ StaticDict.fillMapAll(model); } /** * 初始化新增,修改,查询列表页面数据 * @param model */ public void initAddAndUpdate(ModelMap model) { } /** 保存新增,@Valid标注spirng在绑定对象时自动为我们验证对象属性并存放errors在BindingResult */ @SuppressWarnings("unchecked") @RequestMapping(value = "/save") public String create(ModelMap model,@Valid WzXxfbPdtp wzXxfbPdtp,HttpServletRequest request,HttpServletResponse response)throws Exception { DiskFileItemFactory fac = new DiskFileItemFactory(); ServletFileUpload upload = new ServletFileUpload(fac); upload.setHeaderEncoding("utf-8"); List fileList=null; try { fileList = upload.parseRequest(request); } catch (FileUploadException e1) { e1.printStackTrace(); } //根路径 String root=request.getSession().getServletContext().getRealPath(""); //图片保存完整路径 String savePath = root+File.separator+"pdtpFolder"+File.separator; File f1 = new File(savePath); if (!f1.exists()) { f1.mkdirs(); } //图片名称 String name = ""; //新生成的图片名称 String newName = ""; //扩展名 String extName = ""; String message = ""; boolean flag = true; Iterator<FileItem> it = fileList.iterator(); while (it.hasNext()) { FileItem item = it.next(); //给取表单域的值，赋给wzXxfbPdtp对象 setFormFields(wzXxfbPdtp, item); // 如果是文件类型字段 if (!item.isFormField()) { name = item.getName(); long size = item.getSize(); if(size>(1024*1024)){ message="文件"+item.getName()+"大超过了1M，上传失败！"; break; } // 扩展名格式： if (name.lastIndexOf(".") >= 0) { extName = name.substring(name.lastIndexOf(".")); } // 定义允许上传的文件类型 List<String> fileTypes = new ArrayList<String>(); fileTypes.add(".jpg"); fileTypes.add(".jpeg"); fileTypes.add(".gif"); fileTypes.add(".png"); if(!fileTypes.contains(extName.toLowerCase())){ message = "只允许上传jpg,jpeg,gif,png格式的图片"; flag = false; } if(flag) { DateFormat df = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ssSSS"); Calendar calendar = Calendar.getInstance(); //以当前时间为文件名 格式如：2011-09-03-19-30-36047 newName = df.format(calendar.getTime()); //name = UUID.randomUUID().toString(); File newFile = new File(savePath + newName + extName); item.write(newFile); message="上传文件"+item.getName()+"成功"; model.addAttribute("successFileName",newName + extName); //设置图片的相对地址 wzXxfbPdtp.setTpdz("pdtpFolder/"+newName+extName); //图片原名称 wzXxfbPdtp.setTpmc(name); } } } wzXxfbPdtpManager.save(wzXxfbPdtp); // dwzCallback(model,CREATED_SUCCESS); response.setContentType("text/html"); response.setCharacterEncoding("utf-8"); PrintWriter out = response.getWriter(); out.write("<script>parent.callback('"+flag+"','"+message+"')</script>"); // return LIST_ACTION; return null; } /** 保存更新,@Valid标注spirng在绑定对象时自动为我们验证对象属性并存放errors在BindingResult */ @SuppressWarnings("unchecked") @RequestMapping(value="/{id}/update",method=RequestMethod.POST) public String update(ModelMap model,@PathVariable java.lang.String id,@Valid WzXxfbPdtp wzXxfbPdtp,BindingResult errors,HttpServletRequest request,HttpServletResponse response) throws Exception { DiskFileItemFactory fac = new DiskFileItemFactory(); ServletFileUpload upload = new ServletFileUpload(fac); upload.setHeaderEncoding("utf-8"); List fileList=null; try { fileList = upload.parseRequest(request); } catch (FileUploadException e1) { e1.printStackTrace(); } String root=request.getSession().getServletContext().getRealPath(""); String savePath = root+File.separator+"pdtpFolder"+File.separator; File f1 = new File(savePath); if (!f1.exists()) { f1.mkdirs(); } String name = ""; String newName = ""; String extName = ""; String message = ""; //修改之前 图片地址 String oldFilePath = ""; boolean flag = true; wzXxfbPdtp.setPkid(id); Iterator<FileItem> it = fileList.iterator(); while (it.hasNext()) { FileItem item = it.next(); setFormFields(wzXxfbPdtp, item); if(item.isFormField()){ String field = item.getFieldName(); if(field.equals("oldFilePath")){ oldFilePath = item.getString("utf-8"); wzXxfbPdtp.setTpdz(oldFilePath); } if(field.equals("tpmc")){ wzXxfbPdtp.setTpmc(item.getString("utf-8")); } } if (!item.isFormField()) { name = item.getName(); if(name != null && !"".equals(name)){ long size = item.getSize(); if(size>(1024*1024)){ message="文件"+item.getName()+"大超过了1M，上传失败！"; break; } // 扩展名格式： if (name.lastIndexOf(".") >= 0) { extName = name.substring(name.lastIndexOf(".")); } // 定义允许上传的文件类型 List<String> fileTypes = new ArrayList<String>(); fileTypes.add(".jpg"); fileTypes.add(".jpeg"); fileTypes.add(".gif"); fileTypes.add(".png"); if(!fileTypes.contains(extName.toLowerCase())){ message = "只允许上传jpg,jpeg,gif,png格式的图片"; flag = false; } if(flag) { DateFormat df = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ssSSS"); Calendar calendar = Calendar.getInstance(); //以当前时间为文件名 格式如：2011-09-03-19-30-36047 newName = df.format(calendar.getTime()); //name = UUID.randomUUID().toString(); File newFile = new File(savePath + newName + extName); item.write(newFile); message="上传文件"+item.getName()+"成功"; model.addAttribute("successFileName",newName + extName); //设置图片的相对地址 wzXxfbPdtp.setTpdz("pdtpFolder/"+newName+extName); //图片原名称 wzXxfbPdtp.setTpmc(name); } } } } wzXxfbPdtpManager.update(wzXxfbPdtp); if(name != null && !"".equals(name) && flag == true){ File oldImg = new File(root+File.separator+oldFilePath); if(oldImg.exists()){ oldImg.delete(); } } // dwzCallback(model,UPDATE_SUCCESS); response.setContentType("text/html"); response.setCharacterEncoding("utf-8"); PrintWriter out = response.getWriter(); out.write("<script>parent.callbackEdit('"+flag+"','"+message+"')</script>"); // return LIST_ACTION; return null; } /* * 因为前台Form表单的 enctype="multipart/form-data"，不能再通过request.getParameter()来取得参数，只能通过以下的方法：取得Form表单各文本域的值，赋给wzXxfbPdtp对象 */ private void setFormFields(WzXxfbPdtp wzXxfbPdtp, FileItem item) throws UnsupportedEncodingException { if(item.isFormField()){ String field = item.getFieldName(); if(field.equals("zzdm")){ String zzdm = item.getString("utf-8"); wzXxfbPdtp.setZzdm(zzdm); } if(field.equals("bmdm")){ String bmdm = item.getString("utf-8"); wzXxfbPdtp.setBmdm(bmdm); } if(field.equals("tpbt")){ String tpbt = item.getString("utf-8"); wzXxfbPdtp.setTpbt(tpbt); } if(field.equals("tplj")){ String tplj = item.getString("utf-8"); wzXxfbPdtp.setTplj(tplj); } if(field.equals("kd")){ String kd = item.getString("utf-8"); wzXxfbPdtp.setKd(Integer.parseInt(kd)); } if(field.equals("gd")){ String gd = item.getString("utf-8"); wzXxfbPdtp.setGd(Integer.parseInt(gd)); } if(field.equals("sfpd")){ String sfpd = item.getString("utf-8"); wzXxfbPdtp.setSfpd(sfpd); } } } /** 删除 */ @RequestMapping(value = "/{id}/delete") public String delete(ModelMap model,@PathVariable java.lang.String id,HttpServletRequest request) { WzXxfbPdtp pdtp = wzXxfbPdtpManager.getById(id); String path = pdtp.getTpdz(); //得到图片存放的完整路径 String folder = path.substring(0, path.lastIndexOf("/")); //得到图片的名称 String name = path.substring(path.lastIndexOf("/")+1); //得到图片存放的完整路径 String savePath = request.getSession().getServletContext().getRealPath("")+File.separator+folder+File.separator+name; wzXxfbPdtpManager.removeById(id); File f1 = new File(savePath); if(f1.exists()){ f1.delete(); } dwzCallback(model,DELETE_SUCCESS); return LIST_ACTION; } /** 批量删除 */ @RequestMapping(value = "/batchDeletes") public String batchDelete(ModelMap model,@RequestParam("items") String items,HttpServletRequest request) { String[] arr_items = items.split(","); WzXxfbPdtp pdtp = null; for(int i = 0; i < arr_items.length; i++) { pdtp = wzXxfbPdtpManager.getById(arr_items[i]); wzXxfbPdtpManager.removeById(arr_items[i]); String path = pdtp.getTpdz(); //得到图片存放的完整路径 String folder = path.substring(0, path.lastIndexOf("/")); //得到图片的名称 String name = path.substring(path.lastIndexOf("/")+1); //得到图片存放的完整路径 String savePath = request.getSession().getServletContext().getRealPath("")+File.separator+folder+File.separator+name; File f1 = new File(savePath); if(f1.exists()){ f1.delete(); } } dwzCallback(model,DELETE_SUCCESS); return LIST_ACTION; } /** * DWZ 回调函数,封装了操作的结果 * * @param status */ public void dwzCallback(ModelMap model,String status){ if(CREATED_SUCCESS.equals(status) || UPDATE_SUCCESS.equals(status) || DELETE_SUCCESS.equals(status) ){ Flash.current().success(status); //存放在Flash中的数据,在下一次http请求中仍然可以读取数据,error()用于显示错误消息 /** * statusCode 200:成功 300:失败 301: */ model.addAttribute("statusCode", "200"); /** * 返回后需要刷新的 tab 的ID ,如不填写则不刷新 */ model.addAttribute("navTabId", "BM01040000"); /** * 返回后需要调用的 js 方法, closeCurrent: 关闭当前tab页(一般用于在tab页打开的新增,编辑页面) */ if(! DELETE_SUCCESS.equals(status)){ model.addAttribute("callbackType", "closeCurrent"); } /** * 返回后提示栏显示的信息 */ model.addAttribute("message", status); } } } 图片预览需要用到的js: CJL.0.1.min.js ImagePreviewd.js QuickUpload.js 3下面是实现图片预览的servlet Java代码 package com.common.controller; 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(1*1024*1024);//1M 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; } } viewImg.jsp: Html代码 <%@ page language="java" pageEncoding="UTF-8"%> <%@page import="com.common.controller.ImagePreview;"%> <% ImagePreview img = new ImagePreview(); out.write(img.ProcessRequest(request)); %>
下面是截图：
