Question

我正在尝试创建一个多文件上传servlet。我有1个jsp页面，允许用户选择多个文件进行上传。点击＆＃34;上传＆＃34;按钮＆＃34; UploadServlet＆＃34;被称为使用＆＃34; Apache Commons＆＃34;用于在服务器上上传文件的库。下面是我的JSP＆amp;的代码。的servlet。

JSP代码：

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
    <!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=ISO-8859-1">
    <title>Insert title here</title>
    </head>
    <body>
                <form method="post" action="UploadServlet" enctype="multipart/form-data">
                    Select file to upload: <input type="file" name="uploadFile" /><br/>
                    Select file to upload: <input type="file" name="uploadFile2" /><br/>
                    Select file to upload: <input type="file" name="uploadFile3" /><br/>
                    Select file to upload: <input type="file" name="uploadFile4" /><br/>
                <br/><br/>
                <input type="submit" value="Upload" />
                </form>
    </body>
    </html>

Servlet代码：

package org.server.download;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
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;
/**
 * Servlet implementation class UploadServlet
 */
@WebServlet("/UploadServlet")
public class UploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private static final String UPLOAD_DIRECTORY = "upload";
    private static final int THRESHOLD_SIZE     = 1024 * 1024 * 3;  // 3MB
    private static final int MAX_FILE_SIZE      = 1024 * 1024 * 250; // 250MB
    private static final int MAX_REQUEST_SIZE   = 1024 * 1024 * 300; // 3000MB
    /**
     * Default constructor. 
     */
    public UploadServlet() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        //PrintWriter writer = response.getWriter();
        //writer.println("Request does not contain upload data");
        if (!ServletFileUpload.isMultipartContent(request)) {
            PrintWriter writer = response.getWriter();
            writer.println("Request does not contain upload data");
            writer.flush();
            return;
        }

        // configures upload settings
        DiskFileItemFactory factory = new DiskFileItemFactory();
        factory.setSizeThreshold(THRESHOLD_SIZE);
        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

        ServletFileUpload upload = new ServletFileUpload(factory);
        upload.setFileSizeMax(MAX_FILE_SIZE);
        upload.setSizeMax(MAX_REQUEST_SIZE);

        // constructs the directory path to store upload file
        String uploadPath = getServletContext().getRealPath("")
            + File.separator + UPLOAD_DIRECTORY;
        // creates the directory if it does not exist
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()) {
            uploadDir.mkdir();
        }

        try {
            // parses the request's content to extract file data
            List formItems = upload.parseRequest(request);
            Iterator iter = formItems.iterator();

            // iterates over form's fields
            while (iter.hasNext()) {
                FileItem item = (FileItem) iter.next();
                // processes only fields that are not form fields
                if (!item.isFormField()) {
                    String fileName = new File(item.getName()).getName();
                    String filePath = uploadPath + File.separator + fileName;
                    File storeFile = new File(filePath);
                    // saves the file on disk
                    item.write(storeFile);
                }
            }
            request.setAttribute("message", "Upload has been done successfully!");
        } catch (Exception ex) {
            request.setAttribute("message", "There was an error: " + ex.getMessage());
        }
        getServletContext().getRequestDispatcher("/message.jsp").forward(request, response);

    }

}

我按如下方式运行应用程序：

点击上传按钮后。我得到以下例外：

虽然文件正在上传。但我不知道为什么会出现这种异常。任何人都可以帮忙吗？

使用servlet＆amp;上传多个文件时出现异常Apache Commons

0 个答案: