httpcontextfilter.java

一个用struts tiles的在线影院web系统

package com.eline.vod.controller;

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 com.eline.vod.HttpContext;

public class HttpContextFilter implements Filter {

	private final static String FILTER_APPLIED = "MainFilter_Applied";

	public void destroy() {
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// 确保在每次请求仅仅初始化一次
		//System.out.println("TRACE: HttpApplicationFilter.doFilter()");
		if (request.getAttribute(FILTER_APPLIED) == null) {
			request.setAttribute(FILTER_APPLIED, Boolean.TRUE);
			// 初始化HttpContext
			if (request instanceof HttpServletRequest) {
				if (HttpContext.getCurrent() == null)
					HttpContext.setCurrent(new HttpContext((HttpServletRequest)request, (HttpServletResponse)response));
			}
		}
		// 其它操作
		if (request instanceof HttpServletRequest) {
			//System.out.println("TRACE: RequestUrl = " + ((HttpServletRequest) request).getRequestURL());
			//System.out.println("UserPrincipal="+((HttpServletRequest) request).getUserPrincipal());
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig config) throws ServletException {
	}

}