HttpServletRequest关于文件上传实战

小咪咪 2021-07-24 23:08 302阅读 0赞

**一 视图**

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title> 文件上传 </title>
        <meta name="website" content="http://www.crazyit.org" />
    </head>
    <body>
    <form method="post" action="upload"  enctype="multipart/form-data">
        文件名：<input type="text" id="name" name="name" /><br/>
        选择文件：<input type="file" id="file" name="file" /><br/>
        <input type="submit" value="上传" /><br/>
    </form>
    </body>
    </html>

**二 Servlet定义**

package lee;
    
    import javax.servlet.*;
    import javax.servlet.http.*;
    import javax.servlet.annotation.*;
    
    import java.io.*;
    import java.util.*;
    
    
    
    @WebServlet(name="upload" , urlPatterns={"/upload"})
    @MultipartConfig
    public class UploadServlet extends HttpServlet
    {
        public void service(HttpServletRequest request ,
            HttpServletResponse response)
            throws IOException , ServletException
        {
            response.setContentType("text/html;charset=GBK");
            PrintWriter out = response.getWriter();
            request.setCharacterEncoding("GBK");
            // 获取普通请求参数
            String name = request.getParameter("name");
            out.println("普通的name参数为：" + name + "<br/>");
            // 获取文件上传域
            Part part = request.getPart("file");
            // 获取上传文件的文件类型
            out.println("上传文件的的类型为："
                + part.getContentType() + "<br/>");
            //获取上传文件的大小。
            out.println("上传文件的的大小为：" + part.getSize()  + "<br/>");
            // 获取该文件上传域的Header Name
            Collection<String> headerNames = part.getHeaderNames();
            // 遍历文件上传域的Header Name、Value
            for (String headerName : headerNames)
            {
                out.println(headerName + "--->"
                    + part.getHeader(headerName) + "<br/>");
            }
            // 获取包含原始文件名的字符串
            String fileNameInfo = part.getHeader("content-disposition");
            // 提取上传文件的原始文件名
            String fileName = fileNameInfo.substring(
                fileNameInfo.indexOf("filename=\"") + 10 , fileNameInfo.length() - 1);
            // 将上传的文件写入服务器
            part.write(getServletContext().getRealPath("/uploadFiles")
                + "/" + fileName );               // ①
        }
    }

**三 测试**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/05c8fff01c1c41638d13eb2264b245d0.png