跨域请求错误解决

遇到报错：

Access to XMLHttpRequest at 'http://localhost:9090/user-management/login' from origin 'http://localhost:8081' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

1.nodejs 解决

// 使用 cors 中间件，允许所有来源，或者你可以指定某个特定的来源
app.use(cors({
    origin: ['http://localhost:8081'], // 允许来自 http://localhost:8081 的请求
    methods: 'GET,POST', 'PUT', 'DELETE',             // 允许的 HTTP 方法
    allowedHeaders: 'Content-Type',  // 允许的请求头
}));

2.java 解决

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 WebConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**") // 匹配所有路径
                .allowedOrigins("http://localhost:8081") // 允许的前端域
                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS") // 允许的HTTP方法
                .allowedHeaders("*") // 允许的请求头
                .allowCredentials(true); // 是否允许携带Cookie
    }
}