java 支持跨域

web.xml中配置

<filter>
    <filter-name>SimpleCORSFilter</filter-name>
    <filter-class>com.quanzhen.utils.SimpleCORSFilter</filter-class>
    <init-param>
        <param-name>IsCross</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>SimpleCORSFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<filter>

创建对应的类

SimpleCORSFilter

package com.quanzhen.utils;

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

public class SimpleCORSFilter implements Filter {
    private boolean isCross = false;


    public void destroy() {
        isCross = false;
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        if (isCross) {
            HttpServletRequest httpServletRequest = (HttpServletRequest) request;
            HttpServletResponse httpServletResponse = (HttpServletResponse) response;
            System.out.println("拦截请求: " + httpServletRequest.getServletPath());
            httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
            httpServletResponse.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
            httpServletResponse.setHeader("Access-Control-Max-Age", "0");
            httpServletResponse.setHeader("Access-Control-Allow-Headers",
                    "Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With,userId,token");
            httpServletResponse.setHeader("Access-Control-Allow-Credentials", "true");
            httpServletResponse.setHeader("XDomainRequestAllowed", "1");
        }
        chain.doFilter(request, response);
    }


    public void init(FilterConfig filterConfig) throws ServletException {
        String isCrossStr = filterConfig.getInitParameter("IsCross");
        isCross = isCrossStr.equals("true") ? true : false;
        System.out.println(isCrossStr);
    }

}