JSP+Servlet实现文件上传

来源：互联网发布：exe 端口编辑：程序博客网时间：2024/05/16 01:34

需要两个jar包支持:点我下载
demo如下:
index.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>Insert title here</title></head><body>    <form action="uploadServlet" method="post" enctype="multipart/form-data">        图书名称:<input type="text" name="bookName" />        文件:<input type="file" name="file" />        <input type="submit" value="提交" />    </form></body></html>

其中的servlet如下:
UploadServlet.java

package cn.bestchance.servlet;import java.io.File;import java.io.IOException;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.FileItemFactory;import org.apache.commons.fileupload.FileUploadException;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;    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doPost(request, response);    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("utf-8");        response.setCharacterEncoding("utf-8");        response.setContentType("text/html;charset=utf-8");        String bookName = "";        try {            FileItemFactory factory = new DiskFileItemFactory();            ServletFileUpload upload = new ServletFileUpload(factory);            List<FileItem> items = upload.parseRequest(request);            for (FileItem fileItem : items) {                if(!fileItem.isFormField()){                    String fileName = fileItem.getName();                    //限制只能上传图片                    if(fileName.endsWith(".jpg") || fileName.endsWith(".jpeg") || fileName.endsWith(".png")){                        String rootPath = getServletContext().getRealPath("image/");                        File file = new File(rootPath, fileName);                        //写入文件                        fileItem.write(file);                    }else{//上传的不是图片                        response.getWriter().println("<script>alert('请上传格式为jpg,png,jpeg类型的图片！！！');window.location.href='index.jsp'</script>");                    }                }else{ //不是文件类型，则为普通属性                    if("bookName".equals(fileItem.getFieldName())){                        bookName = fileItem.getString("utf-8");                        System.out.println(bookName);//输出到控制台测试                    }                }            }        } catch (Exception e) {            response.getWriter().println("<script>alert('上传图片异常，请重新操作！！！');window.location.href='index.jsp'</script>");        }    }}

需要注意的是：由于表单提交时设置了这个属性:enctype=”multipart/form-data”
因此在servlet中不能使用request.getParamter();方法来获取表单普通属性，因此普通属性的获取需在if中判断，例如demo中的bookName,且需要使用该条语句设置编码格式 bookName = fileItem.getString(“utf-8”);

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