Java学习笔记一Servlet二 ServletContext

灰太狼 2023-07-24 02:40 26阅读 0赞

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打印出来的是发布版项目中的路径  
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## 案例-文件下载 ##

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<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
        <a href = "/code6_war_exploded/successServlet?filename=1.jpg">点我下载</a>
    </body>
    </html>

String filename = req.getParameter("filename");
            ServletContext servletContext = this.getServletContext();
            String realPath = servletContext.getRealPath("/img/"+filename);
            FileInputStream fis = new FileInputStream(realPath);
            String mimeType = servletContext.getMimeType(filename);
            resp.setHeader("content-type", mimeType);
            resp.setHeader("content-disposition", "attachment;filename="+filename);
            ServletOutputStream sos = resp.getOutputStream();
            byte[] buff = new byte[1024*8];
            int len = 0;
            while((len = fis.read(buff)) != -1)
                sos.write(buff, 0, len);
            fis.close();

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