使用servlet过滤器实现跨域功能

1.定义过滤器接口Filter的实现类，实现类中修改respone的头信息，把 “Access-Control-Allow-Origin” 的域名修改问请求方的域名，如下:

package filter;  

import java.io.IOException;  

import javax.servlet.Filter;  

import javax.servlet.FilterChain;  

import javax.servlet.FilterConfig;  

import javax.servlet.ServletException;  

import javax.servlet.ServletRequest;  

import javax.servlet.ServletResponse;  

import javax.servlet.http.HttpServletResponse;  

public class CORSFilter implements Filter {  

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

        HttpServletResponse response = (HttpServletResponse) res;  

        response.setHeader("Access-Control-Allow-Origin", "*");  

        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS, DELETE");  

        response.setHeader("Access-Control-Max-Age", "3600");  

        response.setHeader("Access-Control-Allow-Headers", "x-requested-with, Content-Type");  

        response.setHeader("Access-Control-Allow-Credentials", "true");  

        chain.doFilter(req, res);  

    }  

public void init(FilterConfig filterConfig) {}  

public void destroy() {}  }  

<filter>  

    <filter-name>CORSFilter</filter-name>  

    <filter-class>com.exiao.platform.api.supplier.filter.CORSFilter</filter-class>  

</filter>  

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springboot 服务器端设置允许跨域

package cn.xydata.util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

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

/**
 *  跨域过滤器
 * @author cjq
 * @since 2017年9月26日
 */
@Component
public class CorsFilterUtil implements Filter {

    private static final Logger logger = LoggerFactory.getLogger(CorsFilterUtil.class);

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE,PUT,OPTIONS,PATCH");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        System.out.println("*********************************过滤器被使用**************************");
        chain.doFilter(req, res);
    }
    public void init(FilterConfig filterConfig) {}
    public void destroy() {}
}