tomcat添加跨域访问功能-Access-Control-Allow-Origin:*

目标：tomcat服务器提供的接口，不能在其他域中访问的时候，需要增 Access-Control-Allow-Origin:*

直接配置的方法很多，但是我一个没有成功过，所以只能自己写拦截器了。

1.　编写拦截器代码

　　新建一个类，实现Filter接口，代码如下

package com.itxc.filter;

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

public class CORSFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
        httpResponse.addHeader("Access-Control-Allow-Origin", "*");
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

    }
}

2.　配置web.xml

    <filter>
        <filter-name>CorsFilter</filter-name>
        <filter-class>com.itxc.filter.CORSFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>CorsFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

3. 删除你之前为了这个功能配置的乱起八糟的配置吧

搞定，收工