tomcat添加跨域訪問功能-Access-Control-Allow-Origin:*

目標：tomcat服務器提供的接口，不能在其他域中訪問的時候，需要增 Access-Control-Allow-Origin:* 

直接配置的方法很多，但是我一個沒有成功過，所以只能自己寫攔截器了。

1.　編寫攔截器代碼

　　新建一個類，實現Filter接口，代碼如下

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. 刪除你之前為了這個功能配置的亂起八糟的配置吧

搞定，收工