自定义mvc框架（2）
1. 什么是MVC
MVC全名是Model View Controller，是模型(model)－视图(view)－控制器(controller)的缩写， 它是一种软件设计典范，用一种业务逻辑、数据、界面显示分离的方法组织代码 Model1 jsp+jdbc
Model2 ->MVC
核心思想：各司其职
2. MVC结构
V jsp/ios/android C servlet/action M 实体域模型(名词) 过程域模型(动词)
3. 自定义MVC工作原理图
主控制动态调用子控制器调用完成具体的业务逻辑 （火车、控制台、车轨） 请求、主控制器、子控制器
5. 通过XML对自定义mvc框架进行增强
将Action的信息配置到xml(反射实例化)
通过结果码控制页面的跳转
将一组相关的操作放到一个Action中(反射调用方法) DispatcherAction methodName:add/minus/mul/div CalAction extends DispatcherAction 提供一组与execute方法的参数、返回值相同的方法，只有方法名不一样
利用ModelDriver接口对Java对象进行赋值(反射读写方法) BeanUtils.populate(calBean, parameterMap);
ModelDriver接口返回的对象不能为空
使得框架的配置文件可变
下面展示一些 内联代码片 Cal
package com.lrc.entity;
public class Cal {
private String num1;
private String num2;
public String getNum1() {
return num1;
}
public void setNum1(String num1) {
this.num1 = num1;
}
public String getNum2() {
return num2;
}
public void setNum2(String num2) {
this.num2 = num2;
}
public Cal(String num1, String num2) {
super();
this.num1 = num1;
this.num2 = num2;
}
public Cal() {
super();
}
}
Action接口
package com.lrc.framework;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface Action {
String execute(HttpServletRequest req,HttpServletResponse resp) throws Exception;
}
ActionModel
package com.lrc.framework;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
/**
* 鐢ㄦ潵鎻忚堪action鏍囩
* @author Administrator
*
*/
public class ActionModel implements Serializable{
private static final long serialVersionUID = 6145949994701469663L;
private Map<String, ForwardModel> forwardModels = new HashMap<String, ForwardModel>();
private String path;
private String type;
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public void put(ForwardModel forwardModel){
forwardModels.put(forwardModel.getName(), forwardModel);
}
public ForwardModel get(String name){
return forwardModels.get(name);
}
}
ConfigModel
package com.lrc.framework;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
/**
* 鐢ㄦ潵鎻忚堪config鏍囩
* @author Administrator
*
*/
public class ConfigModel implements Serializable{
private static final long serialVersionUID = -2334963138078250952L;
private Map<String, ActionModel> actionModels = new HashMap<String, ActionModel>();
public void put(ActionModel actionModel){
actionModels.put(actionModel.getPath(), actionModel);
}
public ActionModel get(String name){
return actionModels.get(name);
}
}
ConfigModelFactory
package com.lrc.framework;
import java.io.InputStream;
import java.util.List;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class ConfigModelFactory {
private ConfigModelFactory() {
}
private static ConfigModel configModel = null;
public static ConfigModel newInstance() throws Exception {
return newInstance("mvc.xml");
}
/**
* 工厂模式创建config建模对象
*
* @param path
* @return
* @throws Exception
*/
public static ConfigModel newInstance(String path) throws Exception {
if (null != configModel) {
return configModel;
}
ConfigModel configModel = new ConfigModel();
InputStream is = ConfigModelFactory.class.getResourceAsStream(path);
SAXReader saxReader = new SAXReader();
Document doc = saxReader.read(is);
List<Element> actionEleList = doc.selectNodes("/config/action");
ActionModel actionModel = null;
ForwardModel forwardModel = null;
for (Element actionEle : actionEleList) {
actionModel = new ActionModel();
actionModel.setPath(actionEle.attributeValue("path"));
actionModel.setType(actionEle.attributeValue("type"));
List<Element> forwordEleList = actionEle.selectNodes("forward");
for (Element forwordEle : forwordEleList) {
forwardModel = new ForwardModel();
forwardModel.setName(forwordEle.attributeValue("name"));
forwardModel.setPath(forwordEle.attributeValue("path"));
forwardModel.setRedirect(forwordEle.attributeValue("redirect"));
actionModel.put(forwardModel);
}
configModel.put(actionModel);
}
return configModel;
}
public static void main(String[] args) {
try {
ConfigModel configModel = ConfigModelFactory.newInstance();
ActionModel actionModel = configModel.get("/loginAction");
ForwardModel forwardModel = actionModel.get("failed");
System.out.println(actionModel.getType());
System.out.println(forwardModel.getPath());
} catch (Exception e) {
e.printStackTrace();
}
}
}
ForwardModel
package com.lrc.framework;
import java.io.Serializable;
/**
* 鐢ㄦ潵鎻忚堪forward鏍囩
* @author Administrator
*
*/
public class ForwardModel implements Serializable {
private static final long serialVersionUID = -8587690587750366756L;
private String name;
private String path;
private String redirect;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public String getRedirect() {
return redirect;
}
public void setRedirect(String redirect) {
this.redirect = redirect;
}
}
ActionSupport
package com.lrc.framework;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 增强版子控制器
*原来的子控制器只能一个用户器请求
*当用户有多个请求时，都是操作同一张表
*原有的子控制器代码繁琐
*增强版的作用：
*将一组相关的操作放到一个Action
*/
public class ActionSupport implements Action{
@Override
public String execute(HttpServletRequest req, HttpServletResponse resp) throws Exception {
String methodName=req.getParameter("methodName");
String code=null;
//this在这里指的是CalAction的一个类实例
Method m=this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
m.setAccessible(true);
code=(String)m.invoke(this, req,resp);
return null;
}
}
**DispatcherServlet **
package com.lrc.framework;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.management.RuntimeErrorException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.util.ParameterMap;
import org.apache.commons.beanutils.BeanUtils;
import com.lrc.web.AddCalAction;
import com.lrc.web.CheCalAction;
import com.lrc.web.ChuCalAction;
import com.lrc.web.DelCalAction;
public class DispatcherServlet extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
// private Map<String, Action> map=new HashMap<String, Action>();
private ConfigModel configModel;
public void init() {
/* map.put("/addCal", new AddCalAction());
map.put("/delCal", new DelCalAction());
map.put("/cheCal", new CheCalAction());
map.put("/chuCal", new ChuCalAction());
*/
try {
String xmlPath=this.getInitParameter("xmlPath");
if(xmlPath==null || "".equals(xmlPath)) {
configModel=ConfigModelFactory.newInstance();
}else {
configModel=ConfigModelFactory.newInstance(xmlPath);
}
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
init();
String url= req.getRequestURI();
url=url.substring(url.lastIndexOf("/"), url.lastIndexOf("."));
//Action action=new AddCalAction
//Action action=map.get(url);//这行代码就相当于上面的那行
ActionModel actionModel=configModel.get(url);
if(actionModel==null) {
throw new RuntimeException("配置的标签找不到控制器");
}
try {
Action action=(Action) Class.forName(actionModel.getType()).newInstance();
//action就是com.lrc.web.CalAction
if(action instanceof ModelDrivern) {
ModelDrivern mdDrivern=(ModelDrivern)action;
//此事的model的所有的属性值是null
Object model=mdDrivern.getModel();
BeanUtils.populate(model, req.getParameterMap());
//可以将req.getParameterMap()的值通过反射的方式将其塞进model的实例中
// Map<String , String[]> map=req.getParameterMap();
// Set<Entry<String, String[]>> entrySet=map.entrySet();
// Class<? extends Object> clz=model.getClass();
// for (Entry<String, String[]> entry : entrySet) {
// Field field=clz.getField(entry.getKey());
// field.setAccessible(true);
// field.set(model, entry.getValue());
// }
}
String code=action.execute(req, resp);
ForwardModel forwardModel=actionModel.get(code);
if(forwardModel!=null) {
String jspPath=forwardModel.getPath();
if("false".equals(forwardModel.getRedirect())) {
//做转发处理
req.getRequestDispatcher(jspPath).forward(req, resp);
}else {
resp.sendRedirect(req.getContextPath()+"/"+jspPath);
}
}
} catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
ModelDrivern
package com.lrc.framework;
import com.lrc.entity.Cal;
/**
* 模型驱动接口
* 作用是：将jsp所有传递的参数以及参数值都自动封装到浏览器索要操作的实体类中
*
*/
public interface ModelDrivern<T> {
T getModel();
}
mvc.xml
<?xml version="1.0" encoding="UTF-8"?>
<!--
config标签:可以包含0~N个action标签
-->
<config>
<!-- <action path="/addCal" type="com.lrc.web.AddCalAction">
<forward name="res" path="/calRes.jsp" redirect="false" />
</action>
<action path="/delCal" type="com.lrc.web.DelCalAction">
<forward name="res" path="/calRes.jsp" redirect="false" />
</action>
<action path="/cheCal" type="com.lrc.web.CheCalAction">
<forward name="res" path="/calRes.jsp" redirect="false" />
</action>
<action path="/chuCal" type="com.lrc.web.ChuCalAction">
<forward name="res" path="/calRes.jsp" redirect="false" />
</action> -->
<action path="/cal" type="com.lrc.web.CalAction">
<forward name="res" path="/calRes.jsp" redirect="false" />
</action>
</config>
**CalAction **
package com.lrc.web;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.lrc.entity.Cal;
import com.lrc.framework.ActionSupport;
import com.lrc.framework.ModelDrivern;
/**
* 增强版子控制器
*原来的子控制器只能一个用户器请求
*当用户有多个请求时，都是操作同一张表
*原有的子控制器代码繁琐
*增强版的作用：
*将一组相关的操作放到一个Action
*/
public class CalAction extends ActionSupport implements ModelDrivern<Cal>{
private Cal cal=new Cal();
public String add(HttpServletRequest req, HttpServletResponse resp) throws Exception {
// String num1=req.getParameter("num1");
// String num2=req.getParameter("num2");
// Cal cal=new Cal(num1,num2);
req.setAttribute("res", Integer.valueOf(cal.getNum1())+Integer.valueOf(cal.getNum2()));
//req.getRequestDispatcher("calRes.jsp").forward(req, resp);
return "res";
}
public String del(HttpServletRequest req, HttpServletResponse resp) throws Exception {
// String num1=req.getParameter("num1");
// String num2=req.getParameter("num2");
// Cal cal=new Cal(num1,num2);
req.setAttribute("res", Integer.valueOf(cal.getNum1())-Integer.valueOf(cal.getNum2()));
//req.getRequestDispatcher("calRes.jsp").forward(req, resp);
return "res";
}
public String che(HttpServletRequest req, HttpServletResponse resp) throws Exception {
// String num1=req.getParameter("num1");
// String num2=req.getParameter("num2");
// Cal cal=new Cal(num1,num2);
req.setAttribute("res", Integer.valueOf(cal.getNum1())*Integer.valueOf(cal.getNum2()));
//req.getRequestDispatcher("calRes.jsp").forward(req, resp);
return "res";
}
public String chu(HttpServletRequest req, HttpServletResponse resp) throws Exception {
// String num1=req.getParameter("num1");
// String num2=req.getParameter("num2");
// Cal cal=new Cal(num1,num2);
req.setAttribute("res", Integer.valueOf(cal.getNum1())/Integer.valueOf(cal.getNum2()));
//req.getRequestDispatcher("calRes.jsp").forward(req, resp);
return "res";
}
@Override
public Cal getModel() {
return cal;
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>mvc</display-name>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>com.lrc.framework.DispatcherServlet</servlet-class>
<init-param>
<param-name>xmlPath</param-name>
<param-value>/mvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>
</web-app>
总结
主要是针对action动态配置（参考的web.xml）建模针对于结果码的处理 利用了mvc.xml的result配置，在中央控制器中进行页面的跳转将用户的一组操作放入一个子控制器中 反射的动态方法调用 由jsp传递methodName到后台，完事之后，调用this关键字获取当前的类对象，然后方法对象，进行动态调用建立模型驱动接口，专门用来处理jsp传递到后台参数封装成实体的过程 BeanUtils.propute(model,Map);解决框架配置文件重名问题 web.xml servlet Init-param
