作记录用

请参考https://blog.csdn.net/lizc_lizc/article/details/81155895

第一种:　

　在每个controller上添加 @CrossOrigin

第二种：使用拦截器

　　1、方法一

@Configuration
public class CorsConfig {
@Bean
public CorsFilter corsFilter() {
final UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();
final CorsConfiguration corsConfiguration = new CorsConfiguration();
corsConfiguration.setAllowCredentials(true);
corsConfiguration.addAllowedOrigin("*");
corsConfiguration.addAllowedHeader("*");
corsConfiguration.addAllowedMethod("*");
urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);
return new CorsFilter(urlBasedCorsConfigurationSource);
}
}

2、方法二

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

3、方法三

@WebFilter(urlPatterns = "*")
public class CorsFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {

}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
HttpServletResponse httpResponse = (HttpServletResponse) response;
httpResponse.setCharacterEncoding("UTF-8");
httpResponse.setContentType("application/json; charset=utf-8");
httpResponse.setHeader("Access-Control-Allow-Origin", "*");
httpResponse.setHeader("Access-Control-Allow-Credentials", "true");
httpResponse.setHeader("Access-Control-Allow-Methods", "*");
httpResponse.setHeader("Access-Control-Allow-Headers", "Content-Type,Authorization");
httpResponse.setHeader("Access-Control-Expose-Headers", "*");
filterChain.doFilter(httpRequest, httpResponse);
}

@Override
public void destroy() {

}
}

4、方法四

　　

@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 多个拦截器组成一个拦截器链
        // addPathPatterns 用于添加拦截规则/**表示拦截所有
        registry.addInterceptor(new ApiInterceptor()).addPathPatterns("/**")
        ; 
        super.addInterceptors(registry);
    }
}

public class ApiInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 请求前调用
        System.out.println("拦截了1");
        //response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));
        response.setHeader("Access-Control-Allow-Origin","*");
        response.setHeader("Access-Control-Allow-Methods", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization,SessionToken");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        // 请求过程中调用
        System.out.println();
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // 请求完成时调用
        System.out.println("拦截了3");
    }
}