SpringBoot解決跨域請求的OPTIONS問題

• 定義過濾器

  import javax.servlet.*;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  public class CorsFilter implements Filter {
      @Override
      public void init(FilterConfig filterConfig) {
          // TODO Auto-generated method stub
      }
  
      @Override
      public void doFilter(ServletRequest request, ServletResponse response,
                           FilterChain chain) throws IOException, ServletException {
          if (request instanceof HttpServletRequest) {
              HttpServletResponse httpServletResponse = (HttpServletResponse) response;
              httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
              httpServletResponse.setHeader("Access-Control-Allow-Methods",
                      "POST, GET, OPTIONS, DELETE");
              httpServletResponse.setHeader("Access-Control-Max-Age", "3600");
              httpServletResponse.setHeader("Access-Control-Allow-Headers",
                      "Content-Type, x-requested-with, X-Custom-Header, Authorization");
          }
          chain.doFilter(request, response);
      }
  
      @Override
      public void destroy() {
          // TODO Auto-generated method stub
      }
  }
  

• 註冊過濾器

      @Bean
      public FilterRegistrationBean corsFilterRegistration() {
          FilterRegistrationBean registration = new FilterRegistrationBean();
          registration.setFilter(new CorsFilter());
          registration.addUrlPatterns("/*");
          registration.setName("corsFilter");
          //將其註冊在其他過濾器的前面
          registration.setOrder(0);
          return registration;
      }