前後端專案分離，跨域請求時，後端的兩種配置方式：

1.配置類：

package com.helq3.config;

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;

/**
 * 跨域全域性配置
 */
@Configuration
public class CorsConfig {
    private CorsConfiguration buildConfig(){

        CorsConfiguration configuration = new CorsConfiguration();
        //設定屬性
        //允許跨域請求的地址，*表示所有
        configuration.addAllowedOrigin("*");
        
 
//配置跨域的請求頭
        configuration.addAllowedHeader("*");
        //配置跨域的請求方法
        configuration.addAllowedMethod("*");
        //表示跨域請求的時候使用的是否是同一個session
        configuration.setAllowCredentials(true);
        return configuration;
    }
    @Bean
    public CorsFilter corsFilter(){
        UrlBasedCorsConfigurationSource source 
 
= new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**",buildConfig());
        return new CorsFilter(source);
    }
}

2.Controller上面配置

@CrossOrigin(origins = "*",allowedHeaders = "*",methods = {},allowCredentials = "true")
public class TestController {
}