javax.servlet.http.HttpServletResponse 得到 status_code

javax.servlet.http.HttpServletResponse 得到 status_code

一) 在log4j的日志中需要输出应答的status_code，不用还真不知道，HttpServletResponse接口并没有getStatus()方法。

二) 自己动手，用一个Reponse的装饰器，解决这个问题。这算是一个过滤器和装饰器设计模式的典型应用吧

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;
import javax.servlet.http.HttpServletResponseWrapper;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ying.car.shiro.ShiroUtils;

/**
 * 记录http信息的Filter
 * 
 *
 */
public class HttpInfoLoggingFilter implements Filter{

	private static final Logger LOGGER = LoggerFactory.getLogger(HttpInfoLoggingFilter.class);

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		// 无配置
	}

	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) req;
		StatusExposingServletResponse response = new StatusExposingServletResponse((HttpServletResponse) res);
		
		Integer currentUserId 	 = getCurrentUserId();
		String ip     			 = request.getRemoteAddr();
		String method 			 = request.getMethod();
		String url    			 = request.getRequestURI();
		String characterEncoding = request.getCharacterEncoding();
		String referer			 = request.getHeader("Referer");
		chain.doFilter(request, response);
		int status  =  response.getStatus();
		LOGGER.info("{}, {}, {}, {}, {}, {}, {}", currentUserId, ip, method, characterEncoding, referer, url, status);
	}

	@Override
	public void destroy() {
		// 无动作
	}

	private Integer getCurrentUserId() {
		Integer currentUserId = 0;
		try { currentUserId = ShiroUtils.getPrincipalDomainId(); } catch (Exception e) {} // apache-shiro框架
		return currentUserId;
	}

	//~ ============================================================================================================================
	public static class StatusExposingServletResponse extends HttpServletResponseWrapper implements HttpServletResponse {

		private int status = 200;

		public StatusExposingServletResponse(HttpServletResponse response) {
			super(response);
		}

		@Override
		public void setStatus(int sc) {
			this.status = sc;
			super.setStatus(sc);
		}

		public int getStatus() {
			return status;
		}
	}
}

web.xml

<!-- apache-shiro 核心拦截器 -->
<filter>
	<filter-name>shiroFilter</filter-name>
	<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
	<filter-name>shiroFilter</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- http信息日志过滤器 -->
<filter>
	<filter-name>httpInfoLoggingFilter</filter-name>
	<filter-class>ying.car.filter.HttpInfoLoggingFilter</filter-class>
</filter>
<filter-mapping>
	<filter-name>httpInfoLoggingFilter</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>