当我们在做前后端分离的开发时，在使用fetch交换数据的时候，提示Access-Control-Allow-Origin跨域问题，解决方案跟客户端没关系，修改的是服务端。
一、在过滤器中设置响应头：
@WebFilter(filterName = "CorsFilter ")
public class CorsFilter implements Filter {
@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) res;
HttpServletRequest reqs = (HttpServletRequest) req;
// response.setHeader("Access-Control-Allow-Origin",reqs.getHeader("Origin"));
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);
}
@Override
public void init(FilterConfig filterConfig) {}
@Override
public void destroy() {}
}
二、在spring boot 服务中心添加一个配置文件：
@Configuration
public class CorsConfig extends WebMvcConfigurerAdapter {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**").allowedOrigins("*")
.allowedMethods("GET", "HEAD", "POST","PUT", "DELETE", "OPTIONS")
.allowCredentials(true).maxAge(3600);
}
}
