js点击调用java后台下载文件

青旅半醒 2022-10-17 04:16 271阅读 0赞

java处理下载的逻辑

public String dowmloadElectronicCertificate(HttpServletResponse response,String ywh) {
            
                File filePah = tificateService.dowmloadtificate(ywh);
                RequestElectronicCertificateUtil.download(filePah,response);
    }
    
    
    
    public static HttpServletResponse download(File file, HttpServletResponse response) {
            try {
                // path是指欲下载的文件的路径。
                //File file = new File(path);
                // 取得文件名。
                String filename = file.getName();
                logger.info("下载文件名为======"+filename);
                // 取得文件的后缀名。
                String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
    
                // 以流的形式下载文件。
                InputStream fis = new BufferedInputStream(new FileInputStream(file));
                byte[] buffer = new byte[fis.available()];
                fis.read(buffer);
                fis.close();
                // 清空response
                response.reset();
                // 设置response的Header
                response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
                response.addHeader("Content-Length", "" + file.length());
                OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
                response.setContentType("application/octet-stream");
                toClient.write(buffer);
                toClient.flush();
                toClient.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return response;
        }

js逻辑

//预览
        _previewCert:function ($pEle) {
            var ywh = $pEle.parents("tr").find("td[data-name='ywh']").first().text();
           
            var params = 'ywh='+ywh;
            var url = _ctx + '/oa/Certificate/cert/dowmloadtificate?'+params;
            var form=$("<form>");//定义一个form表单
            form.attr("style","display:none");
            form.attr("target","");
            form.attr("method","post");//请求类型
            form.attr("action",url);//请求地址
            $("body").append(form);//将表单放置在web中
            form.submit();//表单提交
    }