ionic3打包设置二维码下载页

package com.bjtcrj.gms.resource.controller;
import org.apache.commons.io.IOUtils;
import org.springframework.core.io.ResourceLoader;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
@Controller
@RequestMapping({ "/app" })
public class UploadAppController {
    @Resource
    private ResourceLoader resourceLoader;
    @RequestMapping(value = "/downapp",method = RequestMethod.GET)
    public void downloadFile(HttpServletRequest request, HttpServletResponse response, String type) throws IOException {
        String fileName = "wanggeApp.apk";
        String showName = "智慧网格.apk";
        if ("ios".equalsIgnoreCase(type)) {
            fileName = "wanggeApp.ipa";
            showName = "智慧网格.ipa";
        }
        if (fileName != null) {
            InputStream inputStream = null;
            ServletOutputStream servletOutputStream = null;
            String encodeName = URLEncoder.encode(showName, StandardCharsets.UTF_8.toString());
            try {
                String filePath = File.separator + "appload" + File.separator + fileName;
                org.springframework.core.io.Resource resource = resourceLoader.getResource("classpath:" + filePath);
                response.setContentType("application/force-download");
                response.addHeader("Cache-Control", "no-cache, no-store, must-revalidate");
                response.addHeader("charset", "utf-8");
                response.addHeader("Pragma", "no-cache");
                response.setHeader("Content-Disposition", "attachment; filename*=utf-8''" + encodeName);
//                response.setHeader("Content-Disposition", "attachment; filename=\"" + encodeName + "\"; filename*=utf-8''" + encodeName);
                inputStream = resource.getInputStream();
                servletOutputStream = response.getOutputStream();
                IOUtils.copy(inputStream, servletOutputStream);
                response.flushBuffer();
            } catch (Exception e) {
                System.out.println("应用已暂停下载! ---------------- "+fileName);
                response.setHeader("Content-Disposition", "attachment; filename*=utf-8''" + encodeName);
                response.flushBuffer();
//                String data = "应用已暂停下载!";
//                OutputStream outputStream = response.getOutputStream();
//                response.setHeader("content-type", "text/html;charset=UTF-8");
//                byte[] dataByteArr = data.getBytes("UTF-8");
//                outputStream.write(dataByteArr);
            } finally {
                try {
                    if (inputStream != null) {
                        inputStream.close();
                        inputStream = null;
                    }
                    if (servletOutputStream != null) {
                        try {
                            servletOutputStream.close();
                        }catch (Exception e){
                        }
                        servletOutputStream = null;
                    }
                    // 召唤jvm的垃圾回收器
                    System.gc();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}