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", "<请求方域名如:http://www.sohu.com>");
		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() {}

}

2在web.xml中配置此过滤器:

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

启动web服务器，过滤器中配置的请求方可正常调用上述服务的接口了.