Java Web——图像上传
Posted 龙之天族
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一、jsp中：
1 <body> 2 <!-- 注意： 1. type="file"; 2.method="post" ; 3.enctype="multipart/form-data" --> 3 <form action="UploadServlet" method="post" enctype="multipart/form-data"> 4 雇员编号：<input type="text" name="empno"/><br/><br/> 5 雇员姓名：<input type="text" name="ename"/><br/><br/> 6 所在部门： 7 <select name="deptno"> 8 <option value="10">销售部</option> 9 <option value="20">IT部</option> 10 <option value="30">人力部</option> 11 </select><br/><br/> 12 验证码：<input type="text" name="code"><img id="code" alt="请刷新" src="validateCodeServlet" onclick="changeCode()" style="cursor:hand;"><a href="javascript:changeCode()">换一张</a><br/><br/> 13 14 15 头像：<input type="file" name="uploadFile"> 16 <img src="${image_path}" title="${image_name}" width="200" height="200"> 17 <br/><br/> 18 19 <input type="reset" value="重置"/> 20 <input type="submit" value="注册"/> 21 </form> 22 </body> 23 </html>
二、导入工具包
三、servlet中取得数据
package servlet; import java.io.File; import java.io.IOException; import java.util.Date; import java.util.Iterator; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; 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; /** * Servlet implementation class UploadServlet */ @WebServlet("/UploadServlet") public class UploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //判断上传表单是否为multipart/form-data类型 if(ServletFileUpload.isMultipartContent(request)) { try { //1. 创建DiskFileItemFactory对象，设置缓冲区大小和临时文件目录 DiskFileItemFactory factory = new DiskFileItemFactory(); //System.out.println(System.getProperty("java.io.tmpdir"));//默认临时文件夹 //2. 创建ServletFileUpload对象，并设置上传文件的大小限制。 ServletFileUpload sfu = new ServletFileUpload(factory); sfu.setSizeMax(10*1024*1024);//以byte为单位 不能超过10M 1024byte = 1kb 1024kb=1M 1024M = 1G sfu.setHeaderEncoding("utf-8"); //3. 调用ServletFileUpload.parseRequest方法解析request对象，得到一个保存了所有上传内容的List对象。 List<FileItem> fileItemList = sfu.parseRequest(request); Iterator<FileItem> fileItems = fileItemList.iterator(); //4. 遍历list，每迭代一个FileItem对象，调用其isFormField方法判断是否是上传文件 while(fileItems.hasNext()) { FileItem fileItem = fileItems.next(); //普通表单元素 if(fileItem.isFormField()) { String name = fileItem.getFieldName();//name属性值 String value = fileItem.getString("utf-8");//name对应的value值 System.out.println(name + " = "+value); } //<input type="file">的上传文件的元素 else { String fileName = fileItem.getName();//文件名称 System.out.println("原文件名：" + fileName);//Koala.jpg String suffix = fileName.substring(fileName.lastIndexOf(\'.\')); System.out.println("扩展名：" + suffix);//.jpg //新文件名（唯一） String newFileName = new Date().getTime() + suffix; System.out.println("新文件名：" + newFileName);//image\\1478509873038.jpg //5. 调用FileItem的write()方法，写入文件 File file = new File(request.getServletContext().getRealPath("image")+"\\\\"+newFileName); System.out.println(file.getAbsolutePath()); fileItem.write(file); //6. 调用FileItem的delete()方法，删除临时文件 fileItem.delete(); /* * 存储到数据库时注意 * 1.保存源文件名称 Koala.jpg * 2.保存相对路径 image/1478509873038.jpg * */ request.setAttribute("image_name",fileName); request.setAttribute("image_path","image/"+newFileName); request.getRequestDispatcher("/upload.jsp").forward(request, response); } } } catch (FileUploadException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } } } }
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