我有一个Angular应用程序，它向Sping Boot RESTful API发出请求。出于开发目的，我在Spring Boot中设置了一个非常宽松的CORS策略（请注意，对于任何阅读本文并可能复制或粘贴的人，这些并不意味着是安全的生产值）。

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS, DELETE, PATCH");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers",
                "Origin, X-Requested-With, Content-Type, Accept, xsrf-token, authorization");

        response.setHeader("Access-Control-Expose-Headers", "Location");
        response.addHeader("Access-Control-Expose-Headers", "xsrf-token");

        if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
            response.setStatus(HttpServletResponse.SC_OK);
        } else {
            chain.doFilter(req, res);
        }
    }

使用它的@Configuration类：

@Configuration
@EnableGlobalMethodSecurity(prePostEnabled = true)
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private PasswordEncoder passwordEncoder;

    @Autowired
    private SimpleCORSFilter corsFilter;

    @Bean
    @Override
    protected AuthenticationManager authenticationManager() throws Exception {
        return super.authenticationManager();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {

        http.addFilterBefore(corsFilter, ChannelProcessingFilter.class).authorizeRequests().antMatchers("/admin/**")
                .hasAnyAuthority("ROLE_ADMIN").antMatchers(HttpMethod.GET, "/public").permitAll().and()
                .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and().httpBasic()
                .realmName("test").and().csrf().disable();

    }
}

通常情况下，应用程序之间的通信只是找到。我可以检索和发布JSON数据而没有问题。然而，每当我尝试上传图像或运行一些应该下载文件的代码时，我在浏览器（Firefox）控制台中收到以下错误：
阻止的跨域请求：同源策略不允许阅读http：//localhost：8092/report/csv/detail上的远程资源。（原因：CORS请求未成功）。
控制器端点（Java）：

@RequestMapping("/csv/detail")
public ResponseEntity<?> getDetailedCSV(@RequestBody ReportRequestDTO dto) {
    HttpHeaders headers = new HttpHeaders();
    byte[] contents;
    try {
        contents = IOUtils.toByteArray(new FileInputStream(reportService.getPDFSummary((dto))));
        headers.setContentType(MediaType.parseMediaType("application/pdf"));
        headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");
        ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(contents, headers, HttpStatus.OK);
        return response;
    } catch (FileNotFoundException ex) {
        return new ResponseEntity<>(ex.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
    } catch (IOException ex) {
        return new ResponseEntity<>(ex.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);

    }
}

getPDFSummary方法：

@Override
public String getPDFSummary(ReportRequestDTO req) {
    String outputName = outDir + UUID.randomUUID().toString() + ".pdf";
    List<SummaryReport> rows = new ArrayList<>();

    if (req.getStatusType() == ReportStatus.ALL) {
        rows = summaryRepo.getSummaryReportAllStatus(req.getPropertyIDs(), req.getItemIDs(), req.getStart(),
                req.getEnd());
    } else {
        boolean isOpen = req.getStatusType() == ReportStatus.OPEN;
        rows = summaryRepo.getSummaryReport(isOpen, req.getPropertyIDs(), req.getItemIDs(), req.getStart(),
                req.getEnd());
    }

    String html = convertRepsToHtml(rows);
    PdfConverterExtension.exportToPdf(outputName, html, "", options);
    return outputName;
}

此Angular服务与Sping Boot 应用程序联系：

@Injectable()
export class ReportService {
  private baseEndpoint: String = 'http://localhost:8092';
  constructor(private http: HttpClient) {}

  public getReport(req: ReportRequestModel): Observable<Blob> {
    return this.http.post(
      `${this.baseEndpoint}/report/${req.exportType}`,
      req,
      { responseType: 'blob' }
    );
  }
}

虽然我以前也遇到过类似的问题，但我认为Java代码中的CORSFilter可以防止这个错误。