• 自定义mvc02

    在上次的基础上优化功能：

    目录

            1.让中央控制器动态加载存储子控制器

            2.参数传递封装优化

            3.对于方法的可执行结果转发，重定向优化

            4.框架配置文件可变

            1.让中央控制器动态加载存储子控制器

    1. package com.ruojuan.framework;
    2.  
    3. import java.io.IOException;
    4. import java.util.HashMap;
    5. import java.util.Map;
    6.  
    7. import javax.servlet.ServletException;
    8. import javax.servlet.annotation.WebServlet;
    9. import javax.servlet.http.HttpServlet;
    10. import javax.servlet.http.HttpServletRequest;
    11. import javax.servlet.http.HttpServletResponse;
    12.  
    13. import org.apache.commons.beanutils.BeanUtils;
    14. import org.apache.commons.beanutils.PropertyUtils;
    15.  
    16. import com.ruojuan.web.BookAction;
    17.  
    18. /**
    19.  * 中央控制器动态加载子控制器
    20.  * 
    21.  * 中央控制器
    22.  * 		主要职能：接受浏览器请求，找到对应的处理人
    23.  * @author liuruojuan
    24.  *
    25.  * 时间：2022年6月24日下午6:21:20
    26.  */
    27. //@WebServlet("*.action")
    28. public class DispatcherServlet extends HttpServlet{
    29.  
    30. //	private Map<String, Action> actions = new HashMap<String, Action>();
    31. 	
    32. 	/*
    33. 	 * 	通过建模可以知道configModel对象包含config.xml所有子控制器信息
    34. 	 *  同时为了解中央控制器能够动态加载保存子控制器的信息，那么我们只需要引入configModel对象即可
    35. 	 */
    36. 	private ConfigModel configModel;
    37. 	
    38. 	//程序启动时，只会加载一次
    39. 	
    40. 	
    41. 	@Override
    42. 	public void init() throws ServletException {
    43. //		actions.put("/book", new BookAction());
    44. //		actions.put("/book", new BookAction());
    45. 		try {
    46. 			//配置地址
    47. 			//getInitParameter的作用是拿到web.xml中的servlet信息配置参数
    48. 			String configLocation = this.getInitParameter("configLocation");
    49. 			if(configLocation==null||"".equals(configLocation)) {
    50. 				configModel = ConfigModelFactory.bulid();
    51. 			}
    52. 			else {
    53. 				configModel = ConfigModelFactory.bulid(configLocation);
    54. 			}
    55. 		} catch (Exception e) {
    56. 			e.printStackTrace();
    57. 		}
    58. 	}
    59.  
    60. 	@Override
    61. 	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    62. 		doPost(request, response);
    63. 	}
    64. 	
    65. 	@Override
    66. 	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    67. 		// TODO Auto-generated method stub
    68. 		String uri = request.getRequestURI();
    69. 		//要拿到/book,就是最后一个/到最后一个，的位子
    70. 		 uri = uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));
    71. 		
    72. //		 Action action = actions.get(uri);
    73. //		相比于上一种从map集合获取子控制器，当前需要获取config.xml中的全路径名，然后反射实例化
    74. 		 ActionModel actionModel = configModel.pop(uri);
    75. 		 if(actionModel == null) {
    76. 			 throw new RuntimeException("action 配置错误");
    77. 		 }
    78. 		 String type = actionModel.getType();
    79. 		 try {
    80. 			 //type是action子控制器全路径名
    81. 			 Action action = (Action)Class.forName(type).newInstance();
    82. 			//action是bookAction
    83. 			 if(action instanceof ModelDriven) {
    84. 				 ModelDriven md = (ModelDriven) action;
    85. 				//model指的是bookAction中的book实例
    86. 				 Object model = md.getModel();
    87. 				//要给model中的属性赋值，要接受前端jsp参数   req.getParameterMap()
    88. 				//PropertyUtils.getProperty(bean, name);
    89. 				//将前端所有参数值封装进实体类
    90. 				 BeanUtils.populate(model, request.getParameterMap());
    91. 				 System.out.println(model);
    92. 			 }
    93. 			 //正式调用方法前，book中的属性要被赋值
    94. 			 //action.execute(request, response);
    95. 			 String result =  action.execute(request, response);
    96. 			 ForwardModel forwardModel = actionModel.pop(result);
    97. //			 if(forwardModel == null) {
    98. //				 throw new RuntimeException("froward config error");
    99. //			 }
    100. 			 //bookList.jsp  /index.jsp
    101. 			 String path = forwardModel.getPath();
    102. 			//拿到是否需要转发配置
    103. 			 boolean redirect = forwardModel.isRedirect();
    104. 			 if(redirect) {
    105. 				 //${pageContext.request.contextPath}
    106. 				 response.sendRedirect(request.getServletContext().getContextPath()+path);
    107. 			 }
    108. 			 else {
    109. 				 request.getRequestDispatcher(path).forward(request, response);
    110. 			 }
    111. 			 
    112. 			 
    113. 		} catch (Exception e) {
    114. 			e.printStackTrace();
    115. 		}
    116. 	}
    117. 	
    118. 	
    119. }

      2.参数传递封装优化

    假设有很多的属性，这样的方式不可取

            String bid = request.getParameter("bid");
            String bname = request.getParameter("bname");
            String price = request.getParameter("price");
            Book book = new Book();
            book.setBid(Integer.valueOf(bid));
            book.setBname(bname);
            book.setPrice(Float.valueOf(price));
            //bookDao.add(book);
     

     jsp界面传值：

    <h3>参数的传递封装优化</h3>
    <a href="${pageContext.request.contextPath }/order.action?methodName=add&bid=12&bname=liaoliu&price=88">增加</a>
    <a href="${pageContext.request.contextPath }/order.action?methodName=del">删除</a>
    <a href="${pageContext.request.contextPath }/order.action?methodName=edit">修改</a>
    <a href="${pageContext.request.contextPath }/order.action?methodName=list">查看</a>
    <a href="${pageContext.request.contextPath }/order.action?methodName=load">加载</a>
     

    book实体类：

    1. package com.ruojuan.entity;
    2.  
    3. public class Book {
    4. 	
    5. 	private int bid;
    6. 	private String bname;
    7. 	private float price;
    8. 	
    9. 	public int getBid() {
    10. 		return bid;
    11. 	}
    12. 	public void setBid(int bid) {
    13. 		this.bid = bid;
    14. 	}
    15. 	public String getBname() {
    16. 		return bname;
    17. 	}
    18. 	public void setBname(String bname) {
    19. 		this.bname = bname;
    20. 	}
    21. 	public float getPrice() {
    22. 		return price;
    23. 	}
    24. 	public void setPrice(float price) {
    25. 		this.price = price;
    26. 	}
    27. 	public Book() {
    28.  
    29. 	}
    30. 	public Book(int bid, String bname, float price) {
    31. 		this.bid = bid;
    32. 		this.bname = bname;
    33. 		this.price = price;
    34. 	}
    35. 	@Override
    36. 	public String toString() {
    37. 		return "book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
    38. 	}
    39. 	
    40. 	
    41. 	
    42. 	
    43. 	
    44. 	
    45. }

     BookAction

    1. package com.ruojuan.web;
    2.  
    3. import java.io.IOException;
    4.  
    5. import javax.servlet.ServletException;
    6. import javax.servlet.http.HttpServletRequest;
    7. import javax.servlet.http.HttpServletResponse;
    8.  
    9. import com.ruojuan.entity.Book;
    10. import com.ruojuan.framework.Action;
    11. import com.ruojuan.framework.ActionSupport;
    12. import com.ruojuan.framework.ModelDriven;
    13.  
    14. public class BookAction extends ActionSupport implements ModelDriven<Book>{
    15.  
    16. 	private Book book = new Book();
    17. 	
    18. 	private String list(HttpServletRequest request, HttpServletResponse response) {
    19. 		System.out.println("在同一个servlet中调用list方法");
    20. 		return "success";
    21. 	}
    22. 	
    23. 	private void load(HttpServletRequest request, HttpServletResponse response) {
    24. 		System.out.println("在同一个servlet中调用load方法");
    25. 		
    26. 	}
    27.  
    28.  
    29. 	private void edit(HttpServletRequest request, HttpServletResponse response) {
    30. 		System.out.println("在同一个servlet中调用edit方法");
    31. 		
    32. 	}
    33.  
    34. 	private void del(HttpServletRequest request, HttpServletResponse response) {
    35. 		System.out.println("在同一个servlet中调用del方法");
    36. 		
    37. 	}
    38.  
    39. 	private String add(HttpServletRequest request, HttpServletResponse response) {
    40. 		
    41. 		Book book = new Book();
    42. 		//bookDao.add(book);
    43. 		System.out.println("在同一个servlet中调用add方法");
    44. 		return "failed";
    45. 	}
    46.  
    47. 	@Override
    48. 	public Book getModel() {
    49. 		return book;
    50. 	}
    51.  
    52. 	
    53. 	
    54. 	
    55. }

    ActionSupport

    1. package com.ruojuan.framework;
    2.  
    3. import java.io.IOException;
    4. import java.lang.reflect.Method;
    5.  
    6. import javax.servlet.ServletException;
    7. import javax.servlet.http.HttpServletRequest;
    8. import javax.servlet.http.HttpServletResponse;
    9.  
    10. public class ActionSupport implements Action {
    11.  
    12. 	@Override
    13. 	public String execute(HttpServletRequest request, HttpServletResponse response) {
    14. 		 //未来区分当前请求的目的，增删改查的目的，就从前台讲要调用的方法名传递到后台
    15. 		String methodName = request.getParameter("methodName");
    16. 		//methodName可能是add/del/edit/list/load/xxx/...
    17. 		//前台传递什么方法，就调用当前类的方法
    18. 		try {
    19. 			Method m = this.getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
    20. 			m.setAccessible(true);
    21. 			return (String) m.invoke(this, request,response);
    22. 		} catch (Exception e) {
    23. 			e.printStackTrace();
    24. 		}
    25. 		return null;
    26. 		
    27. 	}
    28.  
    29. }

    Action

    1. package com.ruojuan.framework;
    2.  
    3. import java.io.IOException;
    4.  
    5. import javax.servlet.ServletException;
    6. import javax.servlet.http.HttpServletRequest;
    7. import javax.servlet.http.HttpServletResponse;
    8.  
    9. /**
    10.  * 子控制器：
    11.  * 		对应请求的控制人
    12.  * @author liuruojuan
    13.  *
    14.  * 时间：2022年6月24日下午6:22:51
    15.  */
    16. public interface Action {
    17. 	String execute(HttpServletRequest request, HttpServletResponse response) ;
    18.  
    19. }

      3.对于方法的可执行结果转发，重定向优化

    1. 			 //bookList.jsp  /index.jsp
    2. 			 String path = forwardModel.getPath();
    3. 			//拿到是否需要转发配置
    4. 			 boolean redirect = forwardModel.isRedirect();
    5. 			 if(redirect) {
    6. 				 //${pageContext.request.contextPath}
    7. 				 response.sendRedirect(request.getServletContext().getContextPath()+path);
    8. 			 }
    9. 			 else {
    10. 				 request.getRequestDispatcher(path).forward(request, response);
    11. 			 }

        4.框架配置文件可变

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <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">
    3.   <display-name>mvc</display-name>
    4.  <servlet>
    5. 	<servlet-name>mvc</servlet-name>
    6. 	<servlet-class>com.ruojuan.framework.DispatcherServlet</servlet-class>
    7. 	<init-param>
    8. 		<param-name>configLocation</param-name>
    9. 		<param-value>/luoluo</param-value>
    10. 	</init-param>
    11.  </servlet>
    12.  <servlet-mapping>
    13.  	<servlet-name>mvc</servlet-name>
    14.  	<url-pattern>*.action</url-pattern>
    15.  </servlet-mapping>
    16. </web-app>
    1. package com.ruojuan.framework;
    2.  
    3. import java.io.InputStream;
    4. import java.util.List;
    5.  
    6. import org.dom4j.Document;
    7. import org.dom4j.DocumentException;
    8. import org.dom4j.Element;
    9. import org.dom4j.io.SAXReader;
    10.  
    11. /**
    12.  * 23种设计模式之工厂模式
    13.  * sessionfactory
    14.  * ConfigModelFactory就是用来生产configmodel对象
    15.  * 生产出来的ConfigModel对象就包含config.xml中的配置内容
    16.  * 
    17.  * 此地生产configmodel有配置信息？
    18.  * 1.解析config.xml中的配置信息
    19.  * 2.将对应的配置信息分别加载进行不同的模型对象中
    20.  * 
    21.  * @author liuruojuan
    22.  *
    23.  * 时间：2022年6月14日下午5:54:09
    24.  */
    25. public class ConfigModelFactory {
    26.  
    27. 	public static ConfigModel bulid(String path) throws Exception {
    28. 		
    29. 		InputStream in = ConfigModelFactory.class.getResourceAsStream(path);
    30. 		SAXReader sr = new SAXReader();
    31. 		Document read = sr.read(in);
    32. 		List<Element> actionEles = read.selectNodes("/config/action");
    33. 		ConfigModel configModel = new ConfigModel();
    34. 		for (Element actionEle : actionEles) {
    35. 			ActionModel actionModel = new ActionModel();
    36. 			actionModel.setPath(actionEle.attributeValue("path"));
    37. 			actionModel.setType(actionEle.attributeValue("type"));
    38. 			//将forwardmodel赋值并且添加actionmodel中
    39. 			List<Element> forwardEles = actionEle.selectNodes("forward");
    40. 			for (Element element : forwardEles) {
    41. 				ForwardModel forwardModel = new ForwardModel();
    42. 				forwardModel.setName(element.attributeValue("name"));
    43. 				forwardModel.setPath(element.attributeValue("path"));
    44. 				//redirect:只能是false|true，允许空，默认值为false
    45. 				forwardModel.setRedirect("true".equals(element.attributeValue("redirect")));
    46. 				actionModel.push(forwardModel);
    47. 			}
    48. 			configModel.push(actionModel);
    49. 		}
    50. 		return configModel;
    51. 	}
    52. 	
    53. 	public static ConfigModel bulid() throws Exception {
    54. 		String defaultPath = "/config.xml";
    55. 		return bulid(defaultPath);
    56. 	}
    57. }

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  • 原文地址：https://blog.csdn.net/weixin_67338832/article/details/125495266