Example: Spring Boot CORS config

CORSConfig.java

package com.foo.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.web.servlet.config.annotation.CorsRegistration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.Arrays;

@Configuration
public class CORSConfig implements WebMvcConfigurer {
    private final Environment env;

    private static final Logger LOGGER = LoggerFactory.getLogger(CORSConfig.class);

    public SecurityConfig(Environment env) {
        this.env = env;
    }

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        String mapping = env.getProperty("security.policy.cors.mapping");
        String[] urls = env.getProperty("security.policy.cors.allowed-origins", String[].class);
        String[] methods = env.getProperty("security.policy.cors.allowed-methods", String[].class);
        String[] headers = env.getProperty("security.policy.cors.allowed-headers", String[].class);
        Long maxAge = env.getProperty("security.policy.cors.max-age", Long.class);
        CorsRegistration reg = null;
        if (mapping != null) {
            reg = registry.addMapping(mapping);
            LOGGER.info("Added Mapping: " + mapping);
            if (urls != null) {
                reg.allowedOrigins(urls);
                LOGGER.info("Added Origins: " + Arrays.toString(urls));
            }
            if (methods != null) {
                reg.allowedMethods(methods);
                LOGGER.info("Added Methods: " + Arrays.toString(methods));
            }
            if (headers != null) {
                reg.allowedHeaders(headers);
                LOGGER.info("Added Headers: " + Arrays.toString(headers));
            }
            if (maxAge != null) {
                reg.maxAge(maxAge);
                LOGGER.info("Added Max Age: " + maxAge);
            }
        }
    }
}