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Servlet 文件上传

发布者 : @gmail | 发布时间 : 2019-01-05 11:51:20
文章号 : 10 | 阅读量 : 28+1 | AAW值(?) : 1.50 (仅供参考)

upload.jsp

<%--
  Created by IntelliJ IDEA.
  User: adler
  Date: 2018/11/10
  Time: 4:20 PM
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8language="java" %>
<
html>
<
head>
    <
title>Upload Files</title>
</
head>
<
body>
    <
form method="post"action="/Uploader" enctype="multipart/form-data">
        
选择文件:
        <
br>
        <
input type="file"name="uploadFile"/>
        <
br>
        <
input type="submit"value="上传"/>
    </
form>
</
body>
</
html>

Uploader.java

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;
/**
 * Servlet implementation class UploadServlet
 */
@WebServlet("/Uploader")
public class Uploaderextends 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) 
throwsServletException, 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 = request.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
        
request.getServletContext().getRequestDispatcher("/message.jsp").forward(
                request, response);
    }
}

message.jsp

<%@ page language="javacontentType="text/html; charset=UTF-8"
         
pageEncoding="UTF-8"%>
<!DOCTYPE 
html>
<
html>
<
head>
    <
meta http-equiv="Content-Type"content="text/html; charset=UTF-8">
    <
title>文件上传结果</title>
</
head>
<
body>
<
center>
    <
h2>${message}</h2>
</
center>
</
body>
</
html>






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