方法一、SpringBoot的注解@CrossOrigin

直接在Controller方法或者类上增加@CrossOrigin注解，SpringMVC使用@CrossOrigin使用场景要求 jdk1.8+ Spring4.2+

@GetMapping("/hello")
@CrossOrigin
public String hello() {
        return "hello:" + simpleDateFormat.format(new Date());
}

方式二：使用CorsFilter

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

@Configuration
public class ConfigConfiguration {

    @Bean
    public CorsFilter CorsFilter() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOriginPattern("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        corsConfiguration.setAllowCredentials(true);

        UrlBasedCorsConfigurationSource ub = new UrlBasedCorsConfigurationSource();
        ub.registerCorsConfiguration("/**", corsConfiguration);

        return new CorsFilter(ub);
    }
}

方式三：自定义过滤（web? filter）的方式

@Component
public class CustomFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletResponse res = (HttpServletResponse) servletResponse;
        // 设置允许Cookie
        res.addHeader("Access-Control-Allow-Credentials", "true");
        // 允许http://www.xxx.com域（自行设置，这里只做示例）发起跨域请求
        res.addHeader("Access-Control-Allow-Origin", "*");
        // 设置允许跨域请求的方法
        res.addHeader("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT");
        // 允许跨域请求包含content-type
        res.addHeader("Access-Control-Allow-Headers", "Content-Type,X-CAF-Authorization-Token,sessionToken,X-TOKEN");
        if (((HttpServletRequest) servletRequest).getMethod().equals("OPTIONS")) {
            servletResponse.getWriter().println("ok");
            return;
        }
        filterChain.doFilter(servletRequest, servletResponse);
    }
}

?方式四：实现WebMvcConfigurer中addCorsMappings方法

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Component
public class MyWebMvcConfigurer implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")  // 匹配所有的路径
                .allowCredentials(true) // 设置允许凭证
                .allowedHeaders("*")   // 设置请求头
                .allowedMethods("GET", "POST", "PUT", "DELETE") // 设置允许的方式
                .allowedOriginPatterns("*");
    }
}