java学习log4j详细文档和入门工程

package cn.itcast.web; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; @SuppressWarnings("serial") public class CustomerServlet extends HttpServlet { //每个类的前面都必须加 private Logger log=Logger.getLogger(CustomerServlet.class); public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); System.out.println("xxxxxxxxxxxxxxxx"); log.info("a=4"); log.debug("ddd"); try{ Integer.parseInt("aaaaa"); }catch(Exception e){ log.info(e); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }