java使用filter设置跨域访问

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.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class AuthorityFilter implements Filter {

	@Override
	public void destroy() {
		// TODO Auto-generated method stub

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {
		HttpServletResponse nHttpServletResponse = (HttpServletResponse) response;

		HttpServletRequest nHttpServletRequest = (HttpServletRequest) request;

		String nAppKey = nHttpServletRequest.getHeader("Accept-Key");
		if (nAppKey == null || "".equals(nAppKey)) {
			nHttpServletResponse.setStatus(403);
			return;
		} else {
			// 存在则验证准确性
//			if (!nAppKey.toString().equals(XSetting.ZTOKEN_KEY)) {
//				nHttpServletResponse.setStatus(403);
//				return;
//			}
		}

		nHttpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
		nHttpServletResponse.setHeader("Access-Control-Allow-Headers","Accept-Key");
		chain.doFilter(request, nHttpServletResponse);
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub

	}

}