1.思维导图
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?2.代码
? ? ? ? 2.1 BookServlet
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package com.zc.web;
import java.io.IOException;
import java.lang.reflect.Method;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
?* 目标：自定义mvc的工作原理
?* ?1.什么是自定义mvc
?* ??? ?关键：自定义mvc ?框架
?* ?2.它的运行原理
?* ??? ?2.1代码演绎过程
?* ??? ?2.2总结代码运行
?* ?
?* ?mvc
?* ?Model:模型·view视图·controller控制层
?* ?mvc的出现原因：各司其职
?* ?
?* ?不足
?* ? Model模型
?* ? ?? ?Dao层：（增删改查）
?* ? ?? ??? ?1.建立数据库连接
?* ? ?? ??? ?2.预定义对象Preparestatement
?* ? ?? ??? ?3.执行查询
?* ? ?? ??? ?4.处理结果集
?* ? ?? ?通用分页解决了上面问题
?* ? view视图
?* ? ?? ??? ?1.重复的HTML分页条代码
?* ? ?? ??? ?2.重复的js代码
?* ? ?? ??? ?自定义page标签
?* ? controller控制层
?* ? ?? ??? ?1.重写了doGet,doPost,并且doGet没有用
?* ? ?? ??? ?2.参数的封装代码long余了
?* ? ?? ??? ??? ?req.getParammeter("xxxx")
?* ? ?? ??? ?3.对于跳转页面的代码是重复的
?* ? 解决方案:自定义mvc
?* ? ?? ??? ?框架:反射+设计模式,案例：通用分页+自定义标签page标签+自定义mvc的组合就是框架
?* @author My
?*
?*/
public class BookServlet extends HttpServlet{
?? ?@Override
?? ?protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
?? ??? ?// TODO Auto-generated method stub
?? ??? ?doPost(req, resp);
?? ?}
?? ?@Override
?? ?protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
?? ??? ?// TODO Auto-generated method stub
?? ??? ?/**
?? ??? ? * 增删改查缺陷
?? ??? ? * ?? ?当需求发生改变，或者新增加需求的时候，需要改动下面代码 load
?? ??? ? *?
?? ??? ? * ?? ?解决方案
?? ??? ? * ?? ??? ?前台传递methodName到后台，实际就是想要调用当前类对象的methodName方法
?? ??? ? * ?? ??? ?this.methodName
?? ??? ? */
?? ??? ?String methodName = req.getParameter("methodName");
?? ??? ?try {
?? ??? ?Method m = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
?? ??? ?m.setAccessible(true);
?? ??? ?m.invoke(this, req,resp);
?? ??? ?} catch (Exception e) {
?? ??? ??? ?// TODO Auto-generated catch block
?? ??? ??? ?e.printStackTrace();
?? ??? ?}
?? ??? ?/*if("add".equals("methodName")) {
?? ??? ??? ?add(req,resp);
?? ??? ?}
?? ??? ?else if("delete".equals("methodName")){
?? ??? ??? ?delete(req,resp);
?? ??? ?}
?? ??? ?else if("edit".equals("methodName")){
?? ??? ??? ?edit(req,resp);
?? ??? ?}
?? ??? ?else if("list".equals("methodName")){
?? ??? ??? ?list(req,resp);
?? ??? ?}
?? ??? ?else if("load".equals("methodName")){
?? ??? ??? ?load(req,resp);
?? ??? ?}*/
?? ?}
?? ?private void add(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?System.out.println("bookDao.add()..");
?? ?}
?? ?private void delete(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?System.out.println("bookDao.delete()..");
?? ??? ?
?? ?}
?? ?private void edit(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?System.out.println("bookDao.edit()..");
?? ??? ?
?? ?}
?? ?private void list(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?System.out.println("bookDao.list()..");
?? ??? ?
?? ?}
?? ?private void ref(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?//修改页面数据回显
?? ??? ?System.out.println("bookDao.ref()..");
?? ??? ?
?? ?}
?? ?private void load(HttpServletRequest req, HttpServletResponse resp) {
?? ??? ?//修改页面数据回显
?? ??? ?System.out.println("bookDao.load()..");
?? ??? ?
?? ?}
}
? ? ? ? 2.2 BookAction
????????????????
package com.zc.web;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import comzc.framework.ActionSupport;
public class BookAction extends ActionSupport {
private void delete(HttpServletRequest req, HttpServletResponse resp) {
System.out.println("BookAction调用bookDao.delete()..");
}
private void list(HttpServletRequest req, HttpServletResponse resp) {
System.out.println("BookAction调用bookDao.list()..");
}
private void ref(HttpServletRequest req, HttpServletResponse resp) {
// 修改页面数据回显
System.out.println("BookAction调用bookDao.ref()..");
}
}
????????
2.3?Action
?
package comzc.framework;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 1.处理前台浏览器的请求
* 2.运行jsp传递到后台字符串代表的方法
* @author My
*
*/
public interface Action {
public void execut(HttpServletRequest req,HttpServletResponse resp);
/*private void delete(HttpServletRequest req, HttpServletResponse resp) {
System.out.println("bookDao.delete()..");
}
private void list(HttpServletRequest req, HttpServletResponse resp) {
System.out.println("bookDao.list()..");
}
private void ref(HttpServletRequest req, HttpServletResponse resp) {
//修改页面数据回显
System.out.println("bookDao.ref()..");
}*/
}
?2.4?ActionSupport
package comzc.framework;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ActionSupport implements Action {
@Override
public void execut(HttpServletRequest req, HttpServletResponse resp) {
String methodName = req.getParameter("methodName");
try {
Method m = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,
HttpServletResponse.class);
m.setAccessible(true);
m.invoke(this, req, resp);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
2.5?DispatchServlet
package comzc.framework;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.zc.web.BookAction;
/**
* 目标：
* 根据自定义mvc框架的原理图完成框架的研发
* @author My
* 中央控制器
* 寻找子控制器
*
*/
@WebServlet("*.action")
public class DispatchServlet extends HttpServlet{
//存放子控制器的容器
private Map<String,ActionSupport> actions = new HashMap<String,ActionSupport>();
//初始化子控制器容器（集合），经过初始化，actions容器内部就有了子控制器
//init,service,destroy
@Override
public void init() throws ServletException {
// TODO Auto-generated method stub
actions.put("/book", new BookAction());
// actions.put("/order", new BookAction());
// actions.put("/OrderItem", new BookAction());
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
//完成寻找子控制器的过程
//浏览器:http://localhost:8080/j2ee15/book.action?methodName=add
//目标:BookAction.add()...
/**
* 思路
* 1.从浏览器URL中获取到"/book"字符串
* 2.在子控制器容器中拿到BookAction
* 3.BookAction.add()
*
*/
String uri = req.getRequestURI();
uri = uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("/"));
ActionSupport action = actions.get(uri);
}
}
2.6 index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
目前多数人增删改查的代码
<a href="${pageContext.request.contextPath }/book/add">增加</a>
<a href="${pageContext.request.contextPath }/book/delete">删除</a>
<a href="${pageContext.request.contextPath }/book/edit">修改</a>
<a href="${pageContext.request.contextPath }/book/list">查询</a>
V2.0
<a href="${pageContext.request.contextPath }/book.action?methodName=add">增加</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=delete">删除</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=edit">修改</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=list">查询</a>
V3.0
<a href="${pageContext.request.contextPath }/book.action?methodName=load">回显</a>
<a href="${pageContext.request.contextPath }/book.action?methodName=ref">关联</a>
</body>
</html>3.运行结果
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