原始servlet+hibernate+struts2,从前台到后台的整个过程
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" onclick="addUserType()"/>
<input name="btnBack" class="button1" type="button" id="btnBack"
value="返回" onclick="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();
@Override
protected 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()
}
@Override
protected 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">}addTeacherType.jsp xml
<?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
