@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("POST", "GET", "PUT", "OPTIONS", "DELETE")
                .maxAge(3600)
                .allowCredentials(true);
    }
}

@Component
@WebFilter(urlPatterns = "/*", filterName = "authFilter") //這里的“/*” 表示的是需要攔截的請求路徑
public class PassHttpFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException { }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletResponse httpResponse = (HttpServletResponse)servletResponse;
        httpResponse.setHeader("Access-Control-Allow-Headers","Origin, X-Requested-With, Content-Type, Accept");
        httpResponse.setHeader("Access-Control-Allow-Credentials", "true");
        httpResponse.addHeader("Access-Control-Allow-Origin", "http://127.0.0.1:8080");
        filterChain.doFilter(servletRequest, httpResponse);
    }
    @Override
    public void destroy() { }
}