SpringBoot---前端跨域

1.解决方案一：在Controller上添加@CrossOrigin注解

// 注解方式  
@CrossOrigin 
@RestController  
public class LoginController {  
      
     //方法上加入注解
    @CrossOrigin(allowCredentials="true", allowedHeaders="*", methods={RequestMethod.GET,  
            RequestMethod.POST, RequestMethod.DELETE, RequestMethod.OPTIONS,  
            RequestMethod.HEAD, RequestMethod.PUT, RequestMethod.PATCH}, origins="*")  
    @PostMapping("/confirm")  
    public Response handler(@RequestBody Request json){  
          
        return null;  
    }  
}  

解决方案二：全局配置

项目全局配置

    @Configuration  
 public class MyWebConfiguration {  
  
        @Bean  
        public WebMvcConfigurer corsConfigurer() {  
            return new WebMvcConfigurerAdapter() {  
                @Override  
                public void addCorsMappings(CorsRegistry registry) {  
                    registry.addMapping("/**")  
                    .allowCredentials(true)  
                    .allowedMethods("*");  
                }  
            };  
        }  
    }  

解决方案三：通过拦截器/过滤器实现跨域

在spring boot的主类中，增加一个CorsFilter

 @Bean  
public CorsFilter corsFilter() {  
        final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();  
        final CorsConfiguration config = new CorsConfiguration();  
        config.setAllowCredentials(true); // 允许cookies跨域  
        config.addAllowedOrigin("*");// #允许向该服务器提交请求的URI，*表示全部允许，在SpringMVC中，如果设成*，会自动转成当前请求头中的Origin  
        config.addAllowedHeader("*");// #允许访问的头信息,*表示全部  
        config.setMaxAge(18000L);// 预检请求的缓存时间（秒），即在这个时间段里，对于相同的跨域请求不会再预检了  
        config.addAllowedMethod("OPTIONS");// 允许提交请求的方法，*表示全部允许  
        config.addAllowedMethod("HEAD");  
        config.addAllowedMethod("GET");// 允许Get的请求方法  
        config.addAllowedMethod("PUT");  
        config.addAllowedMethod("POST");  
        config.addAllowedMethod("DELETE");  
        config.addAllowedMethod("PATCH");  
        source.registerCorsConfiguration("/**", config);  
        return new CorsFilter(source);  
    }  

或者实现自定义的CorsFilter

@Component
public class CrosFilter implements Filter {
 
    /**
     * 跨域配置
     *
     * @param req http请求
     * @param res http响应
     * @param chain 责任链
     * @throws IOException IO异常
     * @throws ServletException Servlet异常
     */
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, token, language");
        chain.doFilter(req, res);
    }
 
    /**
     * 初始化配置
     *
     * @param filterConfig 初始化配置参数
     */
    public void init(FilterConfig filterConfig) {
    }
 
    /**
     * 配置销毁
     */
    public void destroy() {
    }
}