现在三大框架的兴起ssh spring springmvc 基于注解式的编程简单方便了开发,但是让我感觉摸不着头绪,框架固然是好,提高了开发效率,
对企业有很大的帮助,框架封装的一些底层的东西让我不知道为什么要这么做,只知道该这么做,编程的路线肯定是简单快捷,趋势就是随便点点拖拖,就是一个项目,以后就没有什么代码编程了,我就是好奇为什么要这样,底层的东西到底是什么,闲来无事搞个servlet 玩玩,看看原始的servle怎么干活的,
我习惯先走个流程, 前台页面执行操作后台来处理
一个添加操作,输入点击添加 进入servlet : ../servlet/addTeacherType.html (创建servletshi在web.xml中配置)
1 页面userType_add.jsp
<%@ page language="java" contentType="text/html;charSet=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>添加教师类型</title><link rel="stylesheet" href="../style/myschool.css"/><style type="text/css">
.td1{text-align: right;
}
.td2{text-align: left;
}
</style><script type="text/javascript" src="../script/myschool_validate.js"></script><script type="text/javascript" src="../script/jquery-1.9.1.js"></script><script type="text/javascript">function goBack() {window.self.location="userType_maint.jsp";}function addUserType() {var typeName=jQuery("#typeName").val();if(typeName==""){alert("教师类型不能为空!");}else{//参数typeName:通过post传typeName值 在servlet中req.getParameter("typeName")获取;jQuery.post("../servlet/addTeacherType.html",{typeName:typeName},function(data){alert(JSON.stringify(data)); var www=jQuery(data).find("root").text();alert(www);var r=jQuery(data).find("resultss").text();if(r==1){alert("添加成功!");}else if(r==2){alert("该类型名称已存在!");}else{alert("添加出现异常!"); }},'xml');}}</script></head><body class="body1"><form action="" name="userForm" target="_self" id="userForm" ><div align="center"><table width="95%" border="0" cellspacing="2" cellpadding="2"><tr><td> </td></tr></table><table width="95%" border="0" cellspacing="0" cellpadding="0"><tr><td width="522" class="p1" height="25"><img src="../images/mark_arrow_03.gif" width="14" height="14"/><b>系统管理>>教师维护>>添加</b></td></tr></table><hr width="97%" align="center" size="0"/><table width="95%" border="0" cellpadding="0" cellspacing="0"><tr><td class="td1" width="22%" height="29"><font color="#FF0000">*</font>教师类型名称: </td><td class="td2" width="78%"><input id="typeName" type="text" class="text1" size="10" maxlength="10"/></td></tr></table><hr width="97%" align="center" size="0"/><div align="center"><input name="btnAdd" class="button1" type="button" id="btnAdd"value="添加" οnclick="addUserType()"/><input name="btnBack" class="button1" type="button" id="btnBack"value="返回" οnclick="goBack()" /></div></div></form></body>
</html>
web.xml 配置servlet 在这里servlet找到对应的类执行doPost
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"><display-name></display-name><welcome-file-list><welcome-file>index.html</welcome-file></welcome-file-list><filter><filter-name>struts2</filter-name><filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class></filter><filter-mapping><filter-name>struts2</filter-name><url-pattern>/*</url-pattern></filter-mapping><servlet><!-- 添加教师类型 ,参数:(typeName 类型名称) --><servlet-name>addTeacherType</servlet-name><servlet-class>com.myschool.servlet.AddTeacherTypeServlet</servlet-class></servlet><servlet-mapping><servlet-name>addTeacherType</servlet-name><url-pattern>/servlet/addTeacherType.html</url-pattern></servlet-mapping>
</web-app>
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.myschool.service.TeacherTypeManager;public class AddTeacherTypeServlet extends HttpServlet{//1.页面/myschool/WebRoot/sysmgr/userType_add.jsp 访问servlet (/servlet/addTeacherType.html)//通过web.xml配置的/servlet/addTeacherType.html// 2.定位到servlet 这个类执行dopost();@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {this.doPost(req, resp);//注意这个地方可以开个口 来切dopost()}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {String typeName=req.getParameter("typeName");//获取页面的值标签 name = "typeName"int r=TeacherTypeManager.getInstance().addTeacherType(typeName);//1 .addTeacher.jsp代码 看servle请求http://localhost:8080/项目/servlet/addTeacherType.html?typeName=化学//2. 进入xml 如下/** * <?xml version="1.0" encoding="UTF-8"?>* <%@ page language="java" contentType="text/xml;charSet=UTF-8" * pageEncoding="UTF-8"%>* <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>* <root>* <result><c:out value="${result}"></c:out></result><!-- 1：成功 0：出现异常 2：该教师编号已经存在 -->* </root>*///3. 在页面 var r=jQuery(data).find("result").text();获取xml中result的值req.setAttribute("result", r);//${result}req.getRequestDispatcher("../view/sysmgr/addTeacherType.jsp").forward(req, resp);//发送到xml}
}
hibernate.cfg.xml ,和xxxxx.hbm.xml 就不贴了
service层
import java.util.List;import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import com.myschool.entity.TeacherType;
import com.myschool.util.HibernateUtil;
import com.myschool.util.PageModel;public class TeacherTypeManager {private static TeacherTypeManager instance;public static TeacherTypeManager getInstance(){if(instance==null){instance=new TeacherTypeManager();} return instance;}/*** 根据类型名称查找类型对象* @param typeName* @return*/public TeacherType getTeacherType(String typeName){Session session=HibernateUtil.getSessionFactory().getCurrentSession();try{session.beginTransaction();List list=session.createQuery("from TeacherType where name=?").setString(0,typeName).list();if(list.size()>0){return (TeacherType)list.get(0);}}catch(Exception e){e.printStackTrace();}finally{//session.close();session.getSessionFactory().close();}return null;}/*** 根据类型名称添加教师类型* @param typeName* @return*/public int addTeacherType(String typeName){Session session=HibernateUtil.getSessionFactory().getCurrentSession();try{session.beginTransaction();TeacherType tt=this.getTeacherType(typeName);if(tt==null){tt=new TeacherType();tt.setName(typeName);//这里保存的时候有待解决 持有的对象不可以保存 session.merge(tt);return 1;}else{return 2;}}catch(Exception e){e.printStackTrace();return 3;}finally{session.getTransaction().commit();session.getSessionFactory().close();}<span style="font-family: Arial, Helvetica, sans-serif;"> </span><pre name="code" class="java">}
<?xml version="1.0" encoding="UTF-8"?>
<%@ page language="java" contentType="text/xml;charSet=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<root>ddd<resultss><c:out value="${result}"></c:out></resultss><!-- 1：成功；2：已经存在；3：出现异常 -->
</root>
用get请求时返回的页面
