玩轉SpringBoot 跨域問題的 3 種方案

發布時間：2023-07-03 01:02:29 作者：網友整理

1. 第一種

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
/**
 * @author  Mcally
 * @time    
 * @des     跨越解決方式
 */
@Configuration
public class CorsConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMAppings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("GET", "HEAD", "POST", "PUT", "DELETE", "OPTIONS")
                .allowCredentials(true)
                .maxAge(3600)
                .allowedHeaders("*");
    }
}

這種方式是全局配置的，網上也大都是這種解決辦法，但是很多都是基于舊的spring版本，比如 WebMvcConfigurerAdapter 在spring5.0已經被標記為Deprecated,點開源碼可以看到：

/**
 * An implementation of {@link WebMvcConfigurer} with empty methods allowing
 * subclasses to override only the methods they're interested in.
 *
 * @author Rossen Stoyanchev
 * @since 3.1
 * @deprecated as of 5.0 {@link WebMvcConfigurer} has default methods (made
 * possible by a JAVA 8 baseline) and can be implemented directly without the
 * need for this adapter
 */
@Deprecated
public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {}

2.第二種

import org.springframework.context.annotation.Configuration;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author  Mcally
 * @time    
 * @des     跨越解決方式
 */
@WebFilter(filterName = "CorsFilter")
@Configuration
public class CorsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin","*");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PATCH, DELETE, PUT");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        chain.doFilter(req, res);
    }

}

這種辦法，是基于過濾器的方式，方式簡單明了，就是在response中寫入這些響應頭，好多文章都是第一種和第二種方式都叫你配置，其實這是沒有必要的，只需要一種即可。

3.第三種

/**
 * @author  Mcally
 * @time   
 * @des     跨越解決方式
 */
public class HelloController {
@CrossOrigin(origins = "http://localhost:4000")
@GetMapping("goods-url")
public Response hello(@RequestParam String url) throws Exception {}
}

沒錯就是@CrossOrigin注解，點開注解元注解@Target可以看出，注解可以放在method、class等上面，類似RequestMapping，也就是說，整個controller下面的方法可以都受控制，也可以單個方法受控制。
也可以得知，這個是最小粒度的cors控制辦法了，精確到單個請求級別。