Question

package net.codejava.servlet;

import java.io.File;
import java.io.IOException;

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;

@WebServlet("/UploadServlet")
@MultipartConfig(fileSizeThreshold=1024*1024*2, // 2MB
                 maxFileSize=1024*1024*10,      // 10MB
                 maxRequestSize=1024*1024*50)   // 50MB
public class UploadServlet extends HttpServlet {

    /**
     * Name of the directory where uploaded files will be saved, relative to
     * the web application directory.
     */
    private static final String SAVE_DIR = "uploadFiles";

    /**
     * handles file upload
     */
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // gets absolute path of the web application
        String appPath = request.getServletContext().getRealPath("");
        // constructs path of the directory to save uploaded file
        String savePath = appPath + File.separator + SAVE_DIR;

        // creates the save directory if it does not exists
        File fileSaveDir = new File(savePath);
        if (!fileSaveDir.exists()) {
            fileSaveDir.mkdir();
        }

        for (Part part : request.getParts()) {
            String fileName = extractFileName(part);
            part.write(savePath + File.separator + fileName);
        }

        request.setAttribute("message", "Upload has been done successfully!");
        getServletContext().getRequestDispatcher("/message.jsp").forward(
                request, response);
    }

    /**
     * Extracts file name from HTTP header content-disposition
     */
    private String extractFileName(Part part) {
        String contentDisp = part.getHeader("content-disposition");
        String[] items = contentDisp.split(";");
        for (String s : items) {
            if (s.trim().startsWith("filename")) {
                return s.substring(s.indexOf("=") + 2, s.length()-1);
            }
        }
        return "";
    }
}









<%@ 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>File Upload</title>
</head>
<body>
<center>
    <h1>File Upload</h1>
    <form method="post" action="UploadServlet"
        enctype="multipart/form-data">
        Select file to upload: <input type="file" name="file" size="60" /><br />
        <br /> <input type="submit" value="Upload" />
    </form>
</center>
</body>
</html>




<%@ 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>Upload</title>
</head>
<body>
    <h2>${requestScope.message}</h2>
</body>
</html>




<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
        http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
    id="WebApp_ID" version="2.5">
  <display-name>FileUploadServletExample</display-name>

  <servlet>
    <display-name>FileUploadServlet</display-name>
    <servlet-name>FileUploadServlet</servlet-name>
    <servlet-class>net.codejava.upload.FileUploadServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>FileUploadServlet</servlet-name>
    <url-pattern>/uploadFile</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>upload.jsp</welcome-file>
  </welcome-file-list>
</web-app>

我从某个地方获得了这个代码我已经添加了所需的jar文件Apache Common File Upload 1.2.2和Apache Commons IO 2.3但仍然没有工作说：

请求的资源（/ UploadFile / FileUploadServlet）不可用。

Answer 1

您的注释@WebServlet（“/ UploadServlet”）与web.xml中的url-pattern（即/ uploadfile）不匹配。

因此，我建议您删除为您的Servlet删除web.xml的条目，因为您正在使用注释，不需要在web.xml中输入，而另一个tting在您的jsp文件中进行以下更改：

<form method="post" action="/UploadServlet"
        enctype="multipart/form-data">

如何在jsp servlet中上传文件

1 个答案: