出現錯誤：'Access-Control-Allow-Origin' header 包含多個值 '*, *'，但只允許一個

Question

I tried to make a connection between my Angular frontend and a REST Endpoint in Java / Spring (which I didn't developed and don't know so well). 通過 GET，一切正常。 通過 POST，我在終端收到消息

已被 CORS 策略阻止：對預檢請求的響應未通過訪問控制檢查：請求的資源上不存在“Access-Control-Allow-Origin”header。

並且，在開發工具的“網絡”選項卡中，OPTIONS 方法出現錯誤 403

Request Method: OPTIONS
Status Code: 403 
Remote Address: xx.xx.xx.xx:xxxx
Referrer Policy: strict-origin-when-cross-origin

所以，我在互聯網上搜索了幾次后發現了這種情況，原因是 CORS 設置：通常，在這種情況下，在 POST 之前發送 OPTIONS 調用； 但是，由於 CORS，不允許調用 OPTIONS。 所以，我試圖在我的 controller 上設置這一行

@CrossOrigin(origins = "*", methods = {RequestMethod.OPTIONS, RequestMethod.GET, RequestMethod.POST, RequestMethod.PUT, RequestMethod.DELETE})

這次錯誤改變了

Multiple CORS header 'Access-Control-Allow-Origin' not allowed
But the code I added is the only similar to @CrossOrigin, I dind't found others similar.

因此，根據帖子CORS 問題 - No 'Access-Control-Allow-Origin' header is present on the requested resource ，我嘗試了以下解決方案：

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedMethods("HEAD", "GET", "PUT", "POST", "DELETE", "PATCH");
    }
}

和

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
//        http.csrf().disable();
        http.cors();
    }

    @Bean
    public CorsConfigurationSource corsConfigurationSource() {
        final CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(ImmutableList.of("*"));
        configuration.setAllowedMethods(ImmutableList.of("HEAD",
                "GET", "POST", "PUT", "DELETE", "PATCH"));
        // setAllowCredentials(true) is important, otherwise:
        // The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'.
        configuration.setAllowCredentials(true);
        // setAllowedHeaders is important! Without it, OPTIONS preflight request
        // will fail with 403 Invalid CORS request
        configuration.setAllowedHeaders(ImmutableList.of("Authorization", "Cache-Control", "Content-Type"));
        final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }
}

但是這次我在控制台看到的錯誤變成了

已被 CORS 策略阻止：“Access-Control-Allow-Origin”header 包含多個值“*、*”，但只允許一個。

所以，這是我到達的最后一點。 如何解決關於多個值的最后一個錯誤？ 每次我處理這個問題時，我都會提前一步，錯誤會發生變化，但它仍然存在。

Answer 1

只需將其添加到您的 WebSecurityConfigurerAdapter

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    
/*@Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedMethods("HEAD", "GET", "PUT", "POST", "DELETE", "PATCH");
    }*/ not needed

@Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            // by default uses a Bean by the name of corsConfigurationSource
            .cors(withDefaults())
            ...
    }

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(Arrays.asList("https://localhost:5000"));// if your front end running on localhost:5000
        configuration.setAllowedMethods(Arrays.asList("GET","POST"));
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }
}

確保您沒有任何其他過濾器或注釋 cors 除了上面的代碼

Spring 安全文檔中的 Spring CORS 部分。

如果您不使用 Spring 安全性：

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }


    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurer() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry
                .addMapping("/**")
                .allowedOrigins("*","http://localhost:5000");// list all domains
            }
        };
    }
}