标题：Javaweb中上传图片，获取相对路径，绝对路径
实际上获取的是绝对路径，不过通过浏览器查看到的不会是绝对路径，而是被浏览器保护好，给你看到的一个假的路径，而我们要做的就是获取图片的名字即可，人为的添加一个路径，同时写入到数据库中一个相对路径即可
最后的图片保存的绝对路径【不是图片原来的绝对路径】，
E:\eclipse\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\itcaststore\productImg\11\1
相对路径【数据库中使用相对路径，使得可以在浏览器中显示图片，而使用绝对路径，在浏览器中显示不了图片，只能在eclipse中的内置浏览器中显示图片】：
/productImg/11/1/fec068b5-afd0-4d45-b31b-0f7cddf4f25b.jpg
具体操作：
package cn.itcast.itcaststore.web.servlet.manager;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.lang.reflect.InvocationTargetException;import java.util.HashMap;import java.util.List;import java.util.Map;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import mons.beanutils.BeanUtils;import mons.fileupload.FileItem;import mons.fileupload.FileUploadException;import mons.fileupload.disk.DiskFileItemFactory;import mons.fileupload.servlet.ServletFileUpload;import mons.io.IOUtils;import cn.itcast.itcaststore.domain.Product;import cn.itcast.itcaststore.exception.AddProductException;import cn.itcast.itcaststore.service.ProductService;import cn.itcast.itcaststore.utils.FileUploadUtils;import cn.itcast.itcaststore.utils.IdUtils;/*** 后台系统* 用于添加商品的servlet*/public class AddProductServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 创建javaBean,将上传数据封装.Product p = new Product();Map<String, String> map = new HashMap<String, String>();// 封装商品idmap.put("id", IdUtils.getUUID());DiskFileItemFactory dfif = new DiskFileItemFactory();// 设置临时文件存储位置dfif.setRepository(new File(this.getServletContext().getRealPath("/temp")));// 设置上传文件缓存大小为10mdfif.setSizeThreshold(1024 * 1024 * 10);// 创建上传组件ServletFileUpload upload = new ServletFileUpload(dfif);// 处理上传文件中文乱码upload.setHeaderEncoding("utf-8");try {// 解析request得到所有的FileItemList<FileItem> items = upload.parseRequest(request);// 遍历所有FileItemfor (FileItem item : items) {// 判断当前是否是上传组件if (item.isFormField()) {// 不是上传组件String fieldName = item.getFieldName(); // 获取组件名称String value = item.getString("utf-8"); // 解决乱码问题map.put(fieldName, value);} else {// 是上传组件// 得到上传文件真实名称String fileName = item.getName();fileName = FileUploadUtils.subFileName(fileName);// 得到随机名称String randomName = FileUploadUtils.generateRandonFileName(fileName);// 得到随机目录String randomDir = FileUploadUtils.generateRandomDir(randomName);// 图片存储父目录String imgurl_parent = "/productImg" + randomDir;File parentDir = new File(this.getServletContext().getRealPath(imgurl_parent));// 验证目录是否存在，如果不存在，创建出来if (!parentDir.exists()) {parentDir.mkdirs();}String imgurl = imgurl_parent + "/" + randomName;map.put("imgurl", imgurl);IOUtils.copy(item.getInputStream(), new FileOutputStream(new File(parentDir, randomName)));item.delete();}}} catch (FileUploadException e) {e.printStackTrace();}try {// 将数据封装到javaBean中BeanUtils.populate(p, map);} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}ProductService service = new ProductService();try {// 调用service完成添加商品操作service.addProduct(p);response.sendRedirect(request.getContextPath()+ "/listProduct");return;} catch (AddProductException e) {e.printStackTrace();response.getWriter().write("添加商品失败");return;}}}
<%@ page language="java" pageEncoding="UTF-8"%><HTML><HEAD><meta http-equiv="Content-Language" content="zh-cn"><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><LINK href="${pageContext.request.contextPath}/admin/css/Style.css" type="text/css" rel="stylesheet"></HEAD><body><form id="userAction_save_do" name="Form1"action="${pageContext.request.contextPath}/addProduct" method="post"enctype="multipart/form-data"> <table cellSpacing="1" cellPadding="5" width="100%" align="center"bgColor="#eeeeee" style="border: 1px solid #8ba7e3" border="0"><tr><td class="ta_01" align="center" bgColor="#afd1f3" colSpan="4"height="26"><strong><STRONG>添加商品</STRONG> </strong></td></tr><tr><td align="center" bgColor="#f5fafe" class="ta_01">商品名称：</td><td class="ta_01" bgColor="#ffffff"><input type="text" name="name" class="bg" /></td><td align="center" bgColor="#f5fafe" class="ta_01">商品价格：</td><td class="ta_01" bgColor="#ffffff"><input type="text" name="price" class="bg" /></td></tr><tr><td align="center" bgColor="#f5fafe" class="ta_01">商品数量：</td><td class="ta_01" bgColor="#ffffff"><input type="text" name="pnum" class="bg" /></td><td align="center" bgColor="#f5fafe" class="ta_01">商品类别：</td><td class="ta_01" bgColor="#ffffff"><select name="category" id="category"><option value="" selected="selected">--选择商品类加--</option><option value="文学">文学</option><option value="生活">生活</option><option value="计算机">计算机</option><option value="外语">外语</option><option value="经营">经营</option><option value="励志">励志</option><option value="社科">社科</option><option value="学术">学术</option><option value="少儿">少儿</option><option value="艺术">艺术</option><option value="原版">原版</option><option value="科技">科技</option><option value="考试">考试</option><option value="生活百科">生活百科</option></select></td></tr><tr><td align="center" bgColor="#f5fafe" class="ta_01">商品图片：</td><td class="ta_01" bgColor="#ffffff" colspan="3"><input type="file" name="upload" size="30" value="" /></td></tr><TR><TD class="ta_01" align="center" bgColor="#f5fafe">商品描述：</TD><TD class="ta_01" bgColor="#ffffff" colSpan="3"><textarea name="description" cols="30" rows="3" style="WIDTH: 96%"></textarea></TD></TR><TR><td align="center" colSpan="4" class="sep1"><imgsrc="${pageContext.request.contextPath}/admin/images/shim.gif"></td></TR><tr><td class="ta_01" style="WIDTH: 100%" align="center"bgColor="#f5fafe" colSpan="4"><input type="submit" class="button_ok" value="确定"><FONT face="宋体"> </FONT><input type="reset" value="重置" class="button_cancel"><FONT face="宋体"> </FONT> <INPUT class="button_ok" type="button" onclick="history.go(-1)" value="返回" /><span id="Label1"></span></td></tr></table></form></body></HTML>
