struts_Action 类的扩展

package com.dd.struts.extaction;

import java.io.FileWriter;
import java.io.PrintWriter;

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

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public abstract class ExtAction extends Action {

	/**
	 * Action 类扩展 实现统一异常处理
	 * */
	@Override
	public final ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		ActionForward af = null;
		try {
			af = process(mapping, form, request, response);
		} catch(Exception ex) {
			//ex.printStackTrace();
			//统一异常处理
			String path = this.getServlet().getServletContext().getRealPath("WEB-INF/log.txt");
			FileWriter fw = new FileWriter(path);
			PrintWriter out = new PrintWriter(fw);
			ex.printStackTrace(out);
			out.close();
			fw.close();
			
			af = mapping.findForward("fail");
		}
		return af;
	}
	
	public abstract ActionForward process(ActionMapping mapping,ActionForm form,
			HttpServletRequest request,HttpServletResponse response) 
			throws Exception; 

}

Action 类的扩展 实现异常的统一处理.
DAO 类的所有异常全部抛出.通过这个Action 来写到日志里