[JavaScript知识库]java跨域过滤器解决vue前后端分离跨域问题

java跨域过滤器解决vue前后端分离跨域问题

package com.yoso.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author yoso
 * @date 2021-06-21 21:31
 */
@WebFilter(urlPatterns = "/*")
public class CorsFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {

        HttpServletResponse response = (HttpServletResponse) resp;
        HttpServletRequest request = (HttpServletRequest) req;

        // 此处 setHeader、addHeader 方法都可用。但 addHeader时写多个会报错：“...,but only one is allowed”
        // response.setHeader("Access-Control-Allow-Origin", "*");
        response.addHeader("Access-Control-Allow-Origin", request.getHeader("origin"));
        // 解决预请求（发送2次请求），此问题也可在 nginx 中作相似设置解决。
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with,Cache-Control,Pragma,Content-Type,Token, Content-Type");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        String method = request.getMethod();
        if (method.equalsIgnoreCase("OPTIONS")) {
            response.getOutputStream().write("Success".getBytes("utf-8"));
        } else {
            chain.doFilter(request, response);
        }
    }

    public void init(FilterConfig config) throws ServletException {
    }

}