form表单文件上传 servlet文件接收

时间：2022-01-26 09:40:11

需要导入jar包

Upload.Jsp代码

form表单文件上传 servlet文件接收
<%@ 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>$title$/title>
</head>
<body>
<form method="post" action="/test/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>
</body>
</html>
form表单文件上传 servlet文件接收

servlet接收文件代码

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100 import java.io.File;import java.io.IOException;import java.io.PrintWriter;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.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;    @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);          // 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(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);    }}

 

Servlet3.0新特性：

12345678910111213141516171819202122232425262728293031323334353637383940 import org.apache.catalina.core.ApplicationPart; import javax.servlet.ServletException;import javax.servlet.annotation.MultipartConfig;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.Part;import java.io.IOException;import java.io.PrintWriter; /** * Created by IMP on 2016/9/9. */@WebServlet("UploadServlet")@MultipartConfig(location = "D://")public class UploadServlet extends HttpServlet {    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {          response.setContentType("text/html;charset=UTF-8");        PrintWriter out=response.getWriter();        String path=this.getServletContext().getRealPath("/");        Part p=request.getPart("file1");        if(p.getContentType().contains("image")){            ApplicationPart ap= (ApplicationPart) p;            String fname1=ap.getSubmittedFileName();            int path_idx=fname1.lastIndexOf("\\")+1;            String fname2=fname1.substring(path_idx,fname1.length());            p.write(path+"/upload/"+fname2);            out.write("文件上传成功");        }else{            out.write("请选择图片文件");          }                 }}

　　

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