将Angular字节数组转换为pdf文件

Question

我想将字节数组转换为有角度的pdf文件。 我已经尝试过下面的堆栈溢出解决方案。但是它没有用。

Open pdf from bytes array in angular 5

service.ts

 viewPDF(seqno): any {
        const headers = new HttpHeaders(
          {
            'responseType'  : 'arraybuffer' as 'json'
          }
        );
       return this.httpClient.get<any[]>(environment.apiBaseUrl 
       "intranet/getFileBySeqNo/"+seqno+"",{headers});

    }

component.ts

 this.httpClientService.viewPDF(x).subscribe(data => {
   let file = new Blob([data], { type: 'application/pdf' });            
   var fileURL = URL.createObjectURL(file);
   window.open(fileURL);
 });

java控制器

       public byte[] getFileBySeqNo(int seqNo) {

    String systemGuides =null;
    byte[] pdf = null;
    String sql = "select audio_video_path from slr_r_system_guide 
                          where seq_no=:seqNo";
    try {
        systemGuides =  jdbcTemplate.queryForObject(sql, new 
                    String[] {},String.class);
        Path pdfPath = Paths.get(systemGuides);

        try {
            pdf = Files.readAllBytes(pdfPath);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }   
        } catch (Exception e) {
        logger.error(IILUtils.getStackTraceFromException(e));
       }

      return pdf;
    }

有人可以帮助我吗？