Servlet实现文件上传的三种方法总结

1. 通过getInputStream()取得上传文件。

/** 
 * To change this template, choose Tools | Templates 
 * and open the template in the editor. 
 */ 
package net.individuals.web.servlet; 
 
import java.io.DataInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import javax.servlet.ServletException; 
import javax.servlet.annotation.WebServlet; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
/** 
 * 
 * @author Barudisshu 
 */ 
@WebServlet(name = "UploadServlet", urlPatterns = {"/UploadServlet"}) 
public class UploadServlet extends HttpServlet { 
 
  /** 
   * Processes requests for both HTTP 
   * <code>GET</code> and 
   * <code>POST</code> methods. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  protected void processRequest(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    response.setContentType("text/html;charset=UTF-8"); 
    //读取请求Body 
    byte[] body = readBody(request); 
    //取得所有Body内容的字符串表示 
    String textBody = new String(body, "ISO-8859-1"); 
    //取得上传的文件名称 
    String fileName = getFileName(textBody); 
    //取得文件开始与结束位置 
    Position p = getFilePosition(request, textBody); 
    //输出至文件 
    writeTo(fileName, body, p); 
  } 
 
  //构造类 
  class Position { 
 
    int begin; 
    int end; 
 
    public Position(int begin, int end) { 
      this.begin = begin; 
      this.end = end; 
    } 
  } 
 
  private byte[] readBody(HttpServletRequest request) throws IOException { 
    //获取请求文本字节长度 
    int formDataLength = request.getContentLength(); 
    //取得ServletInputStream输入流对象 
    DataInputStream dataStream = new DataInputStream(request.getInputStream()); 
    byte body[] = new byte[formDataLength]; 
    int totalBytes = 0; 
    while (totalBytes < formDataLength) { 
      int bytes = dataStream.read(body, totalBytes, formDataLength); 
      totalBytes += bytes; 
    } 
    return body; 
  } 
 
  private Position getFilePosition(HttpServletRequest request, String textBody) throws IOException { 
    //取得文件区段边界信息 
    String contentType = request.getContentType(); 
    String boundaryText = contentType.substring(contentType.lastIndexOf("=") + 1, contentType.length()); 
    //取得实际上传文件的气势与结束位置 
    int pos = textBody.indexOf("filename=\""); 
    pos = textBody.indexOf("\n", pos) + 1; 
    pos = textBody.indexOf("\n", pos) + 1; 
    pos = textBody.indexOf("\n", pos) + 1; 
    int boundaryLoc = textBody.indexOf(boundaryText, pos) - 4; 
    int begin = ((textBody.substring(0, pos)).getBytes("ISO-8859-1")).length; 
    int end = ((textBody.substring(0, boundaryLoc)).getBytes("ISO-8859-1")).length; 
 
    return new Position(begin, end); 
  } 
 
  private String getFileName(String requestBody) { 
    String fileName = requestBody.substring(requestBody.indexOf("filename=\"") + 10); 
    fileName = fileName.substring(0, fileName.indexOf("\n")); 
    fileName = fileName.substring(fileName.indexOf("\n") + 1, fileName.indexOf("\"")); 
 
    return fileName; 
  } 
 
  private void writeTo(String fileName, byte[] body, Position p) throws IOException { 
    FileOutputStream fileOutputStream = new FileOutputStream("e:/workspace/" + fileName); 
    fileOutputStream.write(body, p.begin, (p.end - p.begin)); 
    fileOutputStream.flush(); 
    fileOutputStream.close(); 
  } 
 
  // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> 
  /** 
   * Handles the HTTP 
   * <code>GET</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Handles the HTTP 
   * <code>POST</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doPost(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Returns a short description of the servlet. 
   * 
   * @return a String containing servlet description 
   */ 
  @Override 
  public String getServletInfo() { 
    return "Short description"; 
  }// </editor-fold> 
} 

 2. 通过getPart()、getParts()取得上传文件。

    body格式：

POST http://www.example.com HTTP/1.1  
Content-Type:multipart/form-data; boundary=----WebKitFormBoundaryrGKCBY7qhFd3TrwA  
 
------WebKitFormBoundaryrGKCBY7qhFd3TrwA  
Content-Disposition: form-data; name="text"  
 
title  
------WebKitFormBoundaryrGKCBY7qhFd3TrwA  
Content-Disposition: form-data; name="file"; filename="chrome.png"  
Content-Type: image/png  
 
PNG ... content of chrome.png ...  
------WebKitFormBoundaryrGKCBY7qhFd3TrwA--  

 

[html] view plain copy
/** 
 * To change this template, choose Tools | Templates 
 * and open the template in the editor. 
 */ 
package net.individuals.web.servlet; 
 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
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; 
 
/** 
 * 
 * @author Barudisshu 
 */ 
@MultipartConfig 
@WebServlet(name = "UploadServlet", urlPatterns = {"/UploadServlet"}) 
public class UploadServlet extends HttpServlet { 
 
  /** 
   * Processes requests for both HTTP 
   * <code>GET</code> and 
   * <code>POST</code> methods. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  protected void processRequest(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    Part part = request.getPart("photo"); 
    String fileName = getFileName(part); 
    writeTo(fileName, part); 
  } 
 
  //取得上传文件名 
  private String getFileName(Part part) { 
    String header = part.getHeader("Content-Disposition"); 
    String fileName = header.substring(header.indexOf("filename=\"") + 10, header.lastIndexOf("\"")); 
 
    return fileName; 
  } 
 
  //存储文件 
  private void writeTo(String fileName, Part part) throws IOException, FileNotFoundException { 
    InputStream in = part.getInputStream(); 
    OutputStream out = new FileOutputStream("e:/workspace/" + fileName); 
    byte[] buffer = new byte[1024]; 
    int length = -1; 
    while ((length = in.read(buffer)) != -1) { 
      out.write(buffer, 0, length); 
    } 
 
    in.close(); 
    out.close(); 
  } 
 
  // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> 
  /** 
   * Handles the HTTP 
   * <code>GET</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Handles the HTTP 
   * <code>POST</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doPost(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Returns a short description of the servlet. 
   * 
   * @return a String containing servlet description 
   */ 
  @Override 
  public String getServletInfo() { 
    return "Short description"; 
  } 
} 

3、另一种较为简单的方法：采用part的wirte(String fileName)上传，浏览器将产生临时TMP文件

/** 
 * To change this template, choose Tools | Templates 
 * and open the template in the editor. 
 */ 
package net.individuals.web.servlet; 
 
import java.io.IOException; 
import java.io.PrintWriter; 
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; 
 
/** 
 *采用part的wirte(String fileName)上传，浏览器将产生临时TMP文件。 
 * @author Barudisshu 
 */ 
@MultipartConfig(location = "e:/workspace") 
@WebServlet(name = "UploadServlet", urlPatterns = {"/UploadServlet"}) 
public class UploadServlet extends HttpServlet { 
 
  /** 
   * Processes requests for both HTTP 
   * <code>GET</code> and 
   * <code>POST</code> methods. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  protected void processRequest(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    //处理中文文件名 
    request.setCharacterEncoding("UTF-8"); 
    Part part = request.getPart("photo"); 
    String fileName = getFileName(part); 
    //将文件写入location指定的目录 
    part.write(fileName); 
  } 
 
  private String getFileName(Part part) { 
    String header = part.getHeader("Content-Disposition"); 
    String fileName = header.substring(header.indexOf("filename=\"") + 10, header.lastIndexOf("\"")); 
    return fileName; 
  } 
 
  // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> 
  /** 
   * Handles the HTTP 
   * <code>GET</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Handles the HTTP 
   * <code>POST</code> method. 
   * 
   * @param request servlet request 
   * @param response servlet response 
   * @throws ServletException if a servlet-specific error occurs 
   * @throws IOException if an I/O error occurs 
   */ 
  @Override 
  protected void doPost(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    processRequest(request, response); 
  } 
 
  /** 
   * Returns a short description of the servlet. 
   * 
   * @return a String containing servlet description 
   */ 
  @Override 
  public String getServletInfo() { 
    return "Short description"; 
  }// </editor-fold> 
} 

以上就是Servlet实现文件上传的实例，如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！

# Servlet  # 文件上传  # 文件上传的实例  # 文件上传详解  # Java Servlet简单实例分享(文件上传下载demo)  # SpringMVC + servlet3.0 文件上传的配置和实现代码  # Servlet实现多文件上传功能  # Servlet3.0实现文件上传的方法  # servlet+jquery实现文件上传进度条示例代码  # Servlet实现文件上传  # 可多文件上传示例  # java基于servlet使用组件smartUpload实现文件上传  # java基于servlet实现文件上传功能解析  # servlet+JSP+mysql实现文件上传的方法  # Android中发送Http请求(包括文件上传、servlet接收)的实例代码  # 上传  # 上传文件  # 如有  # 希望能  # 三种  # 谢谢大家  # 疑问请  # error  # specific  # response  # throws  # processRequest  # setContentType  # void  # occurs  # protected  # request  # HTTP  # lt 

相关栏目： 【 网站优化151355 】 【 网络推广146373 】 【 网络技术251813 】 【 AI营销90571 】

相关推荐： laravel怎么用DB facade执行原生SQL查询_laravel DB facade原生SQL执行方法  Laravel如何获取当前用户信息_Laravel Auth门面获取用户ID  Laravel怎么生成URL_Laravel路由命名与URL生成函数详解  如何在建站之星网店版论坛获取技术支持？  Python自然语言搜索引擎项目教程_倒排索引查询优化案例  如何选择可靠的免备案建站服务器？  Python并发异常传播_错误处理解析【教程】  微信小程序 wx.uploadFile无法上传解决办法  Laravel模型关联查询教程_Laravel Eloquent一对多关联写法  laravel怎么在请求结束后执行任务（Terminable Middleware）_laravel Terminable Middleware请求结束任务执行方法  google浏览器怎么清理缓存_谷歌浏览器清除缓存加速详细步骤  小米17系列还有一款新机？主打6.9英寸大直屏和旗舰级影像  七夕网站制作视频,七夕大促活动怎么报名？  成都品牌网站制作公司,成都营业执照年报网上怎么办理？  Win11怎么设置虚拟桌面 Win11新建多桌面切换操作【技巧】  Linux后台任务运行方法_nohup与&使用技巧【技巧】  北京网站制作费用多少,建立一个公司网站的费用.有哪些部分,分别要多少钱？  Thinkphp 中 distinct 的用法解析  网站建设整体流程解析，建站其实很容易！  php静态变量怎么调试_php静态变量作用域调试技巧【解答】  高端智能建站公司优选：品牌定制与SEO优化一站式服务  如何续费美橙建站之星域名及服务？  Python文件操作最佳实践_稳定性说明【指导】  如何在不使用负向后查找的情况下匹配特定条件前的换行符  香港服务器租用费用高吗？如何避免常见误区？  PythonWeb开发入门教程_Flask快速构建Web应用  Win11怎么设置默认图片查看器_Windows11照片应用关联设置  如何在橙子建站上传落地页？操作指南详解  如何自定义建站之星模板颜色并下载新样式？  西安专业网站制作公司有哪些,陕西省建行官方网站？  Laravel怎么配置自定义表前缀_Laravel数据库迁移与Eloquent表名映射【步骤】  高端云建站费用究竟需要多少预算？  Laravel Debugbar怎么安装_Laravel调试工具栏配置指南  如何在Tomcat中配置并部署网站项目？  Laravel队列任务超时怎么办_Laravel Queue Timeout设置详解  如何在浏览器中启用Flash_2025年继续使用Flash Player的方法【过时】  在centOS 7安装mysql 5.7的详细教程  如何使用 jQuery 正确渲染 Instagram 风格的标签列表  Laravel如何升级到最新的版本_Laravel版本升级流程与兼容性处理  如何在建站宝盒中设置产品搜索功能？  Windows10电脑怎么设置虚拟光驱_Win10右键装载ISO镜像文件  佛山企业网站制作公司有哪些,沟通100网上服务官网？  悟空识字如何进行跟读录音_悟空识字开启麦克风权限与录音  如何做网站制作流程,*游戏网站怎么搭建？  如何用虚拟主机快速搭建网站？详细步骤解析  JS碰撞运动实现方法详解  Laravel如何设置定时任务（Cron Job）_Laravel调度器与任务计划配置  Laravel如何创建自定义Facades？（详细步骤）  Linux系统运维自动化项目教程_Ansible批量管理实战  rsync同步时出现rsync: failed to set times on “xxxx”: Operation not permitted