@postmapping("/downloadzip")
    public void downloadcerts(httpservletrequest request, httpservletresponse response, @requestbody list<string> ids) throws unsupportedencodingexception {
    	//文件流octet-stream
        response.setcontenttype("application/octet-stream");
        response.setcharacterencoding("utf-8");
        response.addheader("content-disposition", "attachment;filename=" + urlencoder.encode("图片.zip", "utf-8"));
        try {
            zipoutputstream resultstream = new zipoutputstream(response.getoutputstream());
			// 这里是查询数据库
            list<map> result = service.downloadcerts(ids);
            byte[] buffer = new byte[10240];
            for (map map :result) {
            	//因为数据库保存的是图片的base64 所以需要转换
                base64decoder decoder = new base64decoder();
                file certface = new file("temp.png");
                outputstream out = new fileoutputstream(certface);
                byte[] b = decoder.decodebuffer(((string) map.get("certb64")).split(",")[1]);
                for (int i = 0; i <b.length ; i++) {
                    if (b[i] <0) {
                        b[i]+=256;
                    }
                }
                out.write(b);
                out.flush();
                out.close();
                //到这里 base64 转换成了图片
				//往zip里面压入第一个文件  本地文件
                resultstream.putnextentry(new zipentry("本地图片.png" ));
                inputstream stream = new fileinputstream(new file("temp.png"));
                int len;
                // 读入需要下载的文件的内容，打包到zip文件
                while ((len = stream.read(buffer)) > 0) {
                    resultstream.write(buffer, 0, len);
                }
                resultstream.closeentry();
                stream.close();
                resultstream.flush();
                //第一个文件压入完成 关闭流 刷新一下缓冲区
                // 往zip里面压入第二个文件  网络文件 例：https://profile.csdnimg.cn/8/c/e/3_blogdevteam
                resultstream.putnextentry(new zipentry("网络图片.png"));
                url url = new url("https://profile.csdnimg.cn/8/c/e/3_blogdevteam";);
                string str = url.tostring();
                urlconnection connection = url.openconnection();
                inputstream backstream = connection.getinputstream();
                // 读入需要下载的文件的内容，打包到zip文件
                while ((len = backstream.read(buffer)) > 0) {
                    resultstream.write(buffer, 0, len);
                }
                resultstream.closeentry();
                backstream.close();
                resultstream.flush();
				//第二个文件压入完成 关闭流 刷新一下缓冲区
            }
            resultstream.close();
            //关闭流
        } catch (ioexception e) {
            e.printstacktrace();
        }
    }

download(this.ids).then((response) =>{
	if (response.status == 200) {
	    let url = window.url.createobjecturl(new blob([response.data]))
	    let link= document.createelement('a')
	    link.style.display='none'
	    link.href=url
	    link.setattribute('download', "图片.zip")    // 自定义下载文件名（如exemple.txt）
	    document.body.appendchild(link)
	    link.click()
	}else{
	    this.$message.error("下载出错了");
	}
});

responsetype:'blob',