import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class MyController {

    @CrossOrigin(origins = "http://example.com")
    @GetMapping("/data")
    public String getData() {
        return "Data from server";
    }
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 配置類，用于全局設置 CORS（跨域資源共享）配置
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

    /**
     * 配置跨域請求的映射規(guī)則
     * 
     * @param registry 用于注冊 CORS 配置的注冊表
     */
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        // 添加跨域映射規(guī)則
        registry.addMapping("/**")  // 允許所有路徑的跨域請求
                .allowedOrigins("http://example.com")  // 允許來自 http://example.com 的跨域請求
                .allowedMethods("GET", "POST", "PUT", "DELETE")  // 允許的請求方法
                .allowedHeaders("*")  // 允許所有請求頭
                .allowCredentials(true);  // 允許攜帶憑證（如 Cookies）
    }
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class CustomCorsConfig implements WebMvcConfigurer {

    @Bean
    public CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("http://example.com"));
        configuration.setAllowedMethods(Arrays.asList("GET", "POST", "PUT", "DELETE"));
        configuration.setAllowedHeaders(Arrays.asList("*"));
        configuration.setAllowCredentials(true);

        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);

        return source;
    }
}

import org.springframework.boot.autoconfigure.AutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.filter.CorsFilter;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;

@Configuration
@AutoConfiguration
@EnableConfigurationProperties(WebProperties.class)
public class WebAutoConfiguration implements WebMvcConfigurer {

    /**
     * 創(chuàng)建一個 CorsFilter 過濾器的 Bean，配置跨域設置
     *
     * @return 配置了跨域設置的 FilterRegistrationBean
     */
    @Bean
    public FilterRegistrationBean<CorsFilter> corsFilterBean() {
        // 創(chuàng)建 CorsConfiguration 對象
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);  // 允許攜帶憑證（如 Cookies）
        config.addAllowedOriginPattern("*"); // 允許所有來源的請求（注意：生產環(huán)境中通常不建議使用 *，應具體配置允許的域）
        config.addAllowedHeader("*"); // 允許所有請求頭
        config.addAllowedMethod("*"); // 允許所有 HTTP 方法（GET, POST, PUT, DELETE 等）

        // 創(chuàng)建 UrlBasedCorsConfigurationSource 對象
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", config); // 對所有路徑配置跨域設置

        // 創(chuàng)建并返回一個 FilterRegistrationBean 實例，注冊 CorsFilter
        return createFilterBean(new CorsFilter(source), Integer.MIN_VALUE);
    }

    /**
     * 創(chuàng)建 DemoFilter Bean，演示模式
     * 
     * @return 配置了 DemoFilter 的 FilterRegistrationBean
     */
    @Bean
    @ConditionalOnProperty(value = "demo", havingValue = "true")
    public FilterRegistrationBean<DemoFilter> demoFilter() {
        // 創(chuàng)建并返回一個 FilterRegistrationBean 實例，注冊 DemoFilter
        return createFilterBean(new DemoFilter(), Integer.MIN_VALUE);
    }

    /**
     * 創(chuàng)建 FilterRegistrationBean 實例的通用方法
     * 
     * @param filter 需要注冊的過濾器實例
     * @param order  過濾器的執(zhí)行順序
     * @return 配置了過濾器的 FilterRegistrationBean 實例
     */
    public static <T extends Filter> FilterRegistrationBean<T> createFilterBean(T filter, Integer order) {
        FilterRegistrationBean<T> bean = new FilterRegistrationBean<>(filter);
        bean.setOrder(order);  // 設置過濾器的順序
        return bean;
    }
}