JSP 文件上传-团队作业
前端界面已经完成，现在要解决的就是如何将上传的图片发送到servlet服务器，然后处理。
图片本质是文件，我们只需要实现 JSP 文件上传即可。
我写了一个demo做测试
jsp文件上传的基础代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> <div class="container"> <a class="pull-right user_icon" href="javascript: user_page();" id="usericon_label"><i class="free_dot"></i></a> <h1 class="text-muted">基于电厂排放物报告的表格结构化重建</h1> <form action="UploadServlet" method="POST"> <button class="btn btn-lg btn-success" onClick="javascript:document.getElementById('fileupload').click();"> <i class="icons ico-upload"></i> 选择图片<input accept="image/*" id="fileupload" multiple name="file" style="display:none;" type="file"></button> </form> <form method="post" action="UploadServlet" enctype="multipart/form-data"> 选择一个文件: <input type="file" name="uploadFile" /> <br/><br/> <input type="submit" value="上传" /> </form> <div id="files"></div> </div> </body> </html>
import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.util.List; import org.apache.tomcat.util.http.fileupload.FileItem; import org.apache.tomcat.util.http.fileupload.RequestContext; import org.apache.tomcat.util.http.fileupload.disk.DiskFileItemFactory; import org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/UploadServlet") public class UploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; // 上传文件存储目录 private static final String UPLOAD_DIRECTORY = "upload"; // 上传配置 private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3; // 3MB private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB /** * 上传数据及保存文件 */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 检测是否为多媒体上传 if (!ServletFileUpload.isMultipartContent(request)) { // 如果不是则停止 PrintWriter writer = response.getWriter(); writer.println("Error: 表单必须包含 enctype=multipart/form-data"); writer.flush(); return; } // 配置上传参数 DiskFileItemFactory factory = new DiskFileItemFactory(); // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中 factory.setSizeThreshold(MEMORY_THRESHOLD); // 设置临时存储目录 factory.setRepository(new File(System.getProperty("java.io.tmpdir"))); ServletFileUpload upload = new ServletFileUpload(factory); // 设置最大文件上传值 upload.setFileSizeMax(MAX_FILE_SIZE); // 设置最大请求值 (包含文件和表单数据) upload.setSizeMax(MAX_REQUEST_SIZE); // 中文处理 upload.setHeaderEncoding("UTF-8"); // 构造临时路径来存储上传的文件 // 这个路径相对当前应用的目录 String uploadPath = getServletContext().getRealPath("/") + File.separator + UPLOAD_DIRECTORY; // 如果目录不存在则创建 File uploadDir = new File(uploadPath); if (!uploadDir.exists()) { uploadDir.mkdir(); } try { // 解析请求的内容提取文件数据 @SuppressWarnings("unchecked") List<FileItem> formItems = upload.parseRequest((RequestContext) request); if (formItems != null && formItems.size() > 0) { // 迭代表单数据 for (FileItem item : formItems) { // 处理不在表单中的字段 if (!item.isFormField()) { String fileName = new File(item.getName()).getName(); String filePath = uploadPath + File.separator + fileName; File storeFile = new File(filePath); // 在控制台输出文件的上传路径 System.out.println(filePath); // 保存文件到硬盘 item.write(storeFile); request.setAttribute("message", "文件上传成功!"); } } } } catch (Exception ex) { request.setAttribute("message", "错误信息: " + ex.getMessage()); } // 跳转到 message.jsp getServletContext().getRequestDispatcher("/message.jsp").forward(request, response); } }
