解决跨域的三种方式

 跨域

CORS（Cross-Origin Resource Sharing）：跨域资源共享
协议、域名、端口号 - 有一个不同就会出现跨域问题

解决跨域的三种方式

第一种

方法或类上加注解：CorssOrigin

第二种 

引入依赖

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.6.4</version>
        </dependency>

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

第三种

@Configuration
public class CorsConfiguration {
    @Bean
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOriginPatterns("*")
                .allowedMethods("GET", "PUT", "DELETE", "HEAD", "OPTIONS")
                .allowCredentials(true)
                .maxAge(3600)
                .allowedHeaders("*");
    }
}