gdforwardfilter.java

j2ee程序。 spring、xml、 实现增加内容选项。

package com.gd.web.filter;

import java.io.IOException;
import java.lang.reflect.Method;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.gd.mvc.io.InfoInAndOut;
import com.gd.mvc.io.impl.GdInfoInAndOut;

public class GdForwardFilter implements Filter {
	protected FilterConfig config;
	//设定上下文路径
	private ServletContext context;
	private String filterName;
	/**
	 * 初始化Filter，取得上下文路径
	 */
	public void init(FilterConfig config) throws ServletException {
		this.config = config;
		context = config.getServletContext();
		filterName = config.getFilterName();
	}
	/**
	 * 进行过滤
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
		try {
			long startTime = System.currentTimeMillis();
			if (request instanceof HttpServletRequest && response instanceof HttpServletResponse) {
				HttpServletRequest req = (HttpServletRequest)request;
				HttpServletResponse res = (HttpServletResponse)response;
				//返回到指定页面
				forward(req, res);
				context.log("返回到指定页面共使用的时间：" + (System.currentTimeMillis() - startTime) + "ms" +
						"(该日志由 " + filterName + " 报出)");
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			chain.doFilter(request,response);
		}
	}
	/**
	 * 负责页面的返回工作
	 * @param req
	 * @param res
	 * @throws Exception
	 */
	private void forward(HttpServletRequest req, HttpServletResponse res) throws Exception {
		InfoInAndOut infoOut = (req.getAttribute("infoOut") == null) ? new GdInfoInAndOut(req, res) : (InfoInAndOut)req.getAttribute("infoOut");
		//获取Xml文件中使用方法对应的返回页面或在方法中指定的返回也
		String forwardJsp = (infoOut.get("forwardJsp") == null) ? "" : ((String)infoOut.get("forwardJsp")).trim();
		//在方法中指定的sendRedirectJsp页面
		String sendRedirectJsp = (infoOut.get("sendRedirectJsp") == null) ? "" : ((String)infoOut.get("sendRedirectJsp")).trim();
		//在Xml中page中对应的默认返回页面和路径
		String forwardJspInit = (infoOut.get("forwardJspInit") == null) ? "" : ((String)infoOut.get("forwardJspInit")).trim();
		String forwardJspPath = (infoOut.get("forwardJspPath") == null) ? "" : ((String)infoOut.get("forwardJspPath")).trim();
		//在Xml中bean指定的页面所在的文件夹和后缀
		String prefix = (infoOut.get("prefix") == null) ? "" : ((String)infoOut.get("prefix")).trim();
		String suffix = (infoOut.get("suffix") == null) ? "" : ((String)infoOut.get("suffix")).trim();
		
		//假如指定了sendRedirectJsp页面
		if (null != sendRedirectJsp && !"".equals(sendRedirectJsp)) {
			res.sendRedirect(sendRedirectJsp);
		} else {//假如没有指定sendRedirectJsp页面
			if (!"".equals(forwardJsp)) {//表示不管是否设定forward元素，只要使用方法对应的返回页面或在模型层指定的页面
				if ("".equals(prefix) || "".equals(suffix)) {//如果没有设定id为viewResolver的bean，或设定不完整
					RequestDispatcher rd = req.getRequestDispatcher("/"+ (String)infoOut.get("systemName") +"/jsp/" + forwardJsp + ".jsp");
					rd.forward(req, res);
				} else if (!"".equals(prefix) && !"".equals(suffix)){//如果没有设定id为viewResolver的bean，或设定不完整
					if (forwardJsp.indexOf("/") == -1) {//如果forwardJsp中没有指定路径
						RequestDispatcher rd = req.getRequestDispatcher(prefix + forwardJsp + suffix);
						rd.forward(req, res);
					} else {//如果forwardJsp中指定了路径
						RequestDispatcher rd = req.getRequestDispatcher(forwardJsp);
						rd.forward(req, res);
					}
				}
			} else if ("".equals(forwardJspInit) && "".equals(forwardJsp)){//如果即没设定forward元素，也没设定方法对应的返回页面或在模型层指定的页面，抛异常
				throw new Exception("请指定返回页面");
			} else if (!"".equals(forwardJspInit) && "".equals(forwardJsp)){//如果设定了forward元素，没有设定方法对应的返回页面或在模型层指定的页面
				if ("".equals(prefix) || "".equals(suffix)) {//如果没有设定id为viewResolver的bean，或设定不完整
					if ("".equals(forwardJspPath)) {//如果没有设定forward元素的path属性
						RequestDispatcher rd = req.getRequestDispatcher("/"+ (String)infoOut.get("systemName") +"/jsp/" + forwardJspInit + ".jsp");
						rd.forward(req, res);
					} else {//如果设定了forward元素的path属性
						RequestDispatcher rd = req.getRequestDispatcher(forwardJspPath);
						rd.forward(req, res);
					}
				} else if (!"".equals(prefix) && !"".equals(suffix)){//如果没有设定id为viewResolver的bean，或设定不完整
					if ("".equals(forwardJspPath)) {//如果没有设定forward元素的path属性
						RequestDispatcher rd = req.getRequestDispatcher(prefix + forwardJspInit + suffix);
						rd.forward(req, res);
					} else {//如果设定了forward元素的path属性
						RequestDispatcher rd = req.getRequestDispatcher(forwardJspPath);
						rd.forward(req, res);
					}
				}
			}
		}
	}
	/**
	 * 销毁
	 */
	public void destroy() {

	}
}