springmvc和servlet解决跨域问题

springmvc解决跨域：

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

@Configuration//自动配置
public class CrosConfig implements WebMvcConfigurer {
    //重新addCorsMappings方法
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")      //添加映射路径，“/**”表示对所有的路径实行全局跨域访问权限的设置
                .allowedOrigins("*")            //开放哪些ip、端口、域名的访问权限
                .allowedMethods( "GET", "POST", "PUT", "OPTIONS", "DELETE")        //开放哪些Http方法，允许跨域访问
                .allowCredentials(true)         //是否允许发送cookie信息
                .maxAge(3600)
                .allowedHeaders("*");            //允许HTTP请求中的携带哪些Header信息
    }
}

以上是springmvc解决跨域问题的方法，下面是原生servlet项目解决跨域问题的方法：

创建一个拦截器，设置响应头

import javax.servlet.*;
 import javax.servlet.annotation.WebFilter;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 ​
 @WebFilter("*.action")
 public class CORSFilter implements Filter {
 ​
     @Override
     public void init(FilterConfig filterConfig) throws ServletException {
         Filter.super.init(filterConfig);
     }
 ​
     @Override
     public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
         HttpServletResponse resp = (HttpServletResponse) servletResponse;
         HttpServletRequest req = (HttpServletRequest) servletRequest;
         filterChain.doFilter(req,resp);
         resp.setContentType("text/html;charset=UTF-8");
         //禁用缓存，确保网页信息是最新数据
         resp.setHeader("Pragma","No-cache");
         resp.setHeader("Cache-Control","no-cache");
         resp.setHeader("Access-Control-Allow-Origin", "*");
         resp.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, HEAD, DELETE, PUT");
         resp.setHeader("Access-Control-Max-Age", "3600");
         resp.setHeader("Access-Control-Allow-Headers",
                 "X-Requested-With, Content-Type, Authorization, Accept, Origin, User-Agent, Content-Range, Content-Disposition, Content-Description");
 ​
         resp.setDateHeader("Expires", -10);
     }
 ​
     @Override
     public void destroy() {
         Filter.super.destroy();
     }
 }

@WebFilter("*.action")这里的路径根据实际项目更改