第一种方式：创建CorsConfig配置类

package com.ldd.cross.conf;

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;

/**
 * Created by ldd on 2019/3/24.
 */
@Configuration
public class CorsConfig {

    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*"); // 1允许任何域名使用
        corsConfiguration.addAllowedHeader("*"); // 2允许任何头
        corsConfiguration.addAllowedMethod("*"); // 3允许任何方法（post、get等）
        return corsConfiguration;
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", buildConfig()); // 4
        return new CorsFilter(source);
    }
}

第二种方式：创建CorsFilter过滤器实现

package com.ldd.cross.filter;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
 * Created by ldd on 2019/3/24.
 */
@Component
public class CorsFilter implements Filter{

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("init");
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        System.out.println("doFilter");
        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", "x-requested-with");
        System.out.println("*********************************过滤器被使用**************************");
        chain.doFilter(req, res);
    }

    @Override
    public void destroy() {
        System.out.println("destroy");
    }
}