最近在项目中需要实现图片的上传,并且成功后返回图片上传保存路径,通过查找资料探索研究,实现了项目功能需求,记在这方便自己以后查阅,也为有同样需求的码友分享,功能实现比较简单,如果有好的建议和实现方法,还望多多指教。
主要将实现一下两个功能:
1、使用commons-fileupload实现文件的上传(包括图片);
2、使用jquery-form.js实现表单提交成功的回调函数。
页面设计fileupload.jsp:
- <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
- <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>文件上传</title>
- <script src="static/js/jquery.min.js" type="text/javascript"></script>
- <script type="text/javascript" src="static/js/jquery-form.js"></script>
- <script type="text/javascript">
- function subimtBtn() {
- var form = $("form[name=fileForm]");
- var options = {
- url:'${pageContext.servletContext.contextPath}/servlet/imageUploadServlet',
- type:'post',
- success:function(data)
- {
- var jsondata = eval("("+data+")");
- if(jsondata.error == "0"){
- var url = jsondata.url;
- alert(url)
- $("#img").attr("src",url);
- }else{
- var message = jsondata.message;
- alert(message);
- }
- }
- };
- form.ajaxSubmit(options);
- //$("#fileForm").submit();
- }
- </script>
- </head>
- <body>
- <div class="modal-body">
- <form action='${pageContext.servletContext.contextPath}/servlet/imageUploadServlet' enctype="multipart/form-data" method="post" id="fileForm" name="fileForm">
- <input type="file" name="filename">
- </form>
- </div>
- <div class="modal-footer">
- <button class="btn btn-primary" onclick="subimtBtn();">提交</button>
- </div>
- <div>
- <img alt="img" src="" id="img">
- </div>
- </body>
- </html>
servlet实现:imageUploadServlet.java
- package com.system.comtrol;
- import java.io.File;
- import java.io.IOException;
- import java.io.PrintWriter;
- import java.text.SimpleDateFormat;
- import java.util.Arrays;
- import java.util.Date;
- import java.util.HashMap;
- import java.util.Iterator;
- import java.util.List;
- import java.util.Random;
- 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 net.sf.json.JSONObject;
- import org.apache.commons.fileupload.FileItem;
- import org.apache.commons.fileupload.FileItemFactory;
- import org.apache.commons.fileupload.FileUploadException;
- import org.apache.commons.fileupload.disk.DiskFileItemFactory;
- import org.apache.commons.fileupload.servlet.ServletFileUpload;
- /**
- * Servlet implementation class ImageUploadServlet
- */
- @WebServlet("/servlet/imageUploadServlet")
- public class ImageUploadServlet extends HttpServlet {
- private static final long serialVersionUID = 1L;
- /**
- * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse
- * response)
- */
- protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- try {
- PrintWriter out = response.getWriter();
- // 文件保存目录路径
- String savePath = request.getServletContext().getRealPath("/")+ "attached";
- // 文件保存目录URL
- String saveUrl = request.getContextPath() + "/attached";
- // 定义允许上传的文件扩展名
- HashMap<String, String> extMap = new HashMap<String, String>();
- extMap.put("image", "gif,jpg,jpeg,png,bmp");
- // 最大文件大小
- long maxSize = 1000000;
- response.setContentType("text/html; charset=UTF-8");
- if (!ServletFileUpload.isMultipartContent(request)) {
- out.println(getError("请选择文件。"));
- return;
- }
- // 检查目录
- File uploadDir = new File(savePath);
- if (!uploadDir.isDirectory()) {
- out.println(getError("上传目录不存在。"));
- return;
- }
- // 检查目录写权限
- if (!uploadDir.canWrite()) {
- out.println(getError("上传目录没有写权限。"));
- return;
- }
- String dirName = request.getParameter("dir");
- if (dirName == null) {
- dirName = "image";
- }
- if (!extMap.containsKey(dirName)) {
- out.println(getError("目录名不正确。"));
- return;
- }
- // 创建文件夹
- savePath += dirName + "/";
- saveUrl += dirName + "/";
- File saveDirFile = new File(savePath);
- if (!saveDirFile.exists()) {
- saveDirFile.mkdirs();
- }
- SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
- String ymd = sdf.format(new Date());
- savePath += ymd + "/";
- saveUrl += ymd + "/";
- File dirFile = new File(savePath);
- if (!dirFile.exists()) {
- dirFile.mkdirs();
- }
- FileItemFactory factory = new DiskFileItemFactory();
- ServletFileUpload upload = new ServletFileUpload(factory);
- upload.setHeaderEncoding("UTF-8");
- List items = upload.parseRequest(request);
- Iterator itr = items.iterator();
- while (itr.hasNext()) {
- FileItem item = (FileItem) itr.next();
- String fileName = item.getName();
- if (!item.isFormField()) {
- // 检查文件大小
- if (item.getSize() > maxSize) {
- out.println(getError("上传文件大小超过限制。"));
- return;
- }
- // 检查扩展名
- String fileExt = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();
- if (!Arrays.<String> asList(extMap.get(dirName).split(",")).contains(fileExt)) {
- out.println(getError("上传文件扩展名是不允许的扩展名。 只允许" + extMap.get(dirName) + "格式。"));
- return;
- }
- SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
- String newFileName = df.format(new Date()) + "_" + new Random().nextInt(1000) + "." + fileExt;
- try {
- File uploadedFile = new File(savePath, newFileName);
- item.write(uploadedFile);
- } catch (Exception e) {
- out.println(getError("上传文件失败。"));
- return;
- }
- JSONObject obj = new JSONObject();
- obj.put("error", 0);
- obj.put("url", saveUrl + newFileName);
- out.println(obj.toString());
- }
- }
- } catch (FileUploadException e1) {
- e1.printStackTrace();
- }
- }
- private String getError(String message) {
- JSONObject obj = new JSONObject();
- obj.put("error", 1);
- obj.put("message", message);
- return obj.toString();
- }
- }
项目中依赖的主要jar:commons-fileupload-1.2.jar,commons-io-1.4.jar
主要的两个js文件:jquery.min.js,jquery-form.js
这些可以去网上下载,也可以在附件中下载。