目录

一.XML建模

二.工厂模式

三.案例

1.对web.xml进行建模

2.写一个servlet

3.通过url-pattern读取到servlet-class的值

一.XML建模

建模的原理：以面向对象的思想操作

优先从里 进行编码,从里之外

config.xml表的代码块：

 所以的表：

ForwardModel表的代码块：只有属性，没有方法，因为它是空标签

package com.jiangwenjuan.model;


public class ForwardModel {
//	对于这个对象而言，它没有行为，它是空标签，不能添加子标签，它只有属性
//	
//	所以我们就只添加属性
	private String name;
	private String path;
	private boolean 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 boolean isRedirect() {
		return redirect;
	}
	public void setRedirect(boolean redirect) {
		this.redirect = redirect;
	}
	
	
	
}

 ActionModel表：有属性也也两中方法

怎么样才能够新增的思路：

这个就想到与一个容器：你去config表里action里面加一个forward就相当于加了一个空的容器

private Map fMap = new HashMap();

 ActionModel的代码块：

package com.jiangwenjuan.model;

import java.util.HashMap;
import java.util.Map;


public class ActionModel {
//	它就有两个属性，也有两个行为
//	

	private String path;
	private String type;
	private Map fMap = new HashMap();
	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;
	}
	
//	两个行为：增加forwardModel对象,查找forwardModel对象
//	将一个新的forward标签对象加入容器
	public void push(ForwardModel forwardModel) {
		//加到这个容器里面去
		fMap.put(forwardModel.getName(), forwardModel);
	}
	public ForwardModel pop(String name) {
		return fMap.get(name);
	}
	
	
}

代码块的理解：  

对于最外面的ConfigModel表： ConfigModel没有属性只有方法

 万一path有相同的怎么办：所以前面有说值必须是唯一的,如果是相同，当你在压榨的时候，相同的P，你放个不同P,此时你先放进去的就会被覆盖掉。

 ConfigModel代码块：

package com.jiangwenjuan.model;

import java.util.HashMap;
import java.util.Map;


public class ConfigModel {
	private Map aMap = new HashMap();
	
//	两个方法:新增
	public void push(ActionModel actionModel) {
		aMap.put(actionModel.getPath(), actionModel);
	}

	public ActionModel pop(String path) {
		return aMap.get(path);
	}
}

现在通过configmodel拿这个action对象，拿到action对象，在拿里面的type的。

为什么会报空指针异常：因为目前为止现在就只键了一个空壳而已。就会报第三出错.

怎么把configModel和config.xml关联起来，这才是重点 ,刚刚我们只是以面向对象思想去分析和去封装config.xml，但是分析完了之后，你要把config.xml里的内容塞到哪个空壳里面去。那么这一个过程就是把我们的配置文件中的内容封装到实体里面去，这个就称为建模，在这个过程中用到了23种设计模式之工厂模式.

二.工厂模式

Factory:工厂模式的意思。工厂工厂就是用来生产东西的。工厂有个特点：这个工厂类都会以Factory结尾。

ConfigModelFactory代码块：

package com.jiangwenjuan.model;

import java.io.InputStream;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;


public class ConfigModelFactory {
	
	public static ConfigModel bulid() throws Exception {
		String defaultPath = "/config.xml";
		InputStream in = ConfigModelFactory.class.getResourceAsStream(defaultPath);
		SAXReader sr = new SAXReader();
		Document doc = sr.read(in);
//		拿到这里面所有的内容
		List actionEles = doc.selectNodes("/config/action");
		ConfigModel configModel = new ConfigModel();
		for (Element actionEle : actionEles) {//目前只有actionEle里面有值
//			加之前先构建一个actionmodel,这里面还没有值
			ActionModel actionModel = new ActionModel();
			actionModel.setPath(actionEle.attributeValue("path"));
			actionModel.setType(actionEle.attributeValue("type"));
//			还要塞forward,将forwardmodel辅助并且添加到Actionmodel中,怎么拿，去actionEle里面拿
			List forwardEles = actionEle.selectNodes("forward");
			for (Element element : forwardEles) {
				ForwardModel forwardModel = new ForwardModel();
				forwardModel.setName(element.attributeValue("name"));
				forwardModel.setPath(element.attributeValue("path"));
//				redirect:只能是false|true,允许空,默认值为false
				forwardModel.setRedirect("true".equals(element.attributeValue("redirect")));
				actionModel.push(forwardModel);
			}
//			塞到configmodel里面去
			configModel.push(actionModel);
		}
		return configModel;
	}

}

通过这个就可以查找到config.xml里面的内容：

 

package com.jiangwenjuan.model;

public class Demo1 {
	public static void main(String[] args) throws Exception {
//		ConfigModel configModel = new ConfigModel();
		ConfigModel configModel = ConfigModelFactory.bulid();
		ActionModel actionModel = configModel.pop("/loginAction");
		System.out.println(actionModel.getType());
	}

}

案例：拿到config.xml里面第二个action里面的第二个forward里面的path值

不管config.xml有多么复杂，往后只要找东西 ，只要构建对象就可以了，先要去读框架的配置文件，建模。对于很多框架而言不是上面那样写的，是下面这样写的.

这有什么好处呢？你的配置文件变了名字，我可以直接调用它的方法就可以了，并不一定去调用最下面那个方法里面的名字。

package com.jiangwenjuan.model;

import java.io.InputStream;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;


public class ConfigModelFactory {
	
	public static ConfigModel bulid(String path) throws Exception {
		InputStream in = ConfigModelFactory.class.getResourceAsStream(path);
		SAXReader sr = new SAXReader();
		Document doc = sr.read(in);
//		拿到这里面所有的内容
		List actionEles = doc.selectNodes("/config/action");
		ConfigModel configModel = new ConfigModel();
		for (Element actionEle : actionEles) {//目前只有actionEle里面有值
//			加之前先构建一个actionmodel,这里面还没有值
			ActionModel actionModel = new ActionModel();
			actionModel.setPath(actionEle.attributeValue("path"));
			actionModel.setType(actionEle.attributeValue("type"));
//			还要塞forward,将forwardmodel辅助并且添加到Actionmodel中,怎么拿，去actionEle里面拿
			List forwardEles = actionEle.selectNodes("forward");
			for (Element element : forwardEles) {
				ForwardModel forwardModel = new ForwardModel();
				forwardModel.setName(element.attributeValue("name"));
				forwardModel.setPath(element.attributeValue("path"));
//				redirect:只能是false|true,允许空,默认值为false
				forwardModel.setRedirect("true".equals(element.attributeValue("redirect")));
				actionModel.push(forwardModel);
			}
//			塞到configmodel里面去
			configModel.push(actionModel);
		}
		return configModel;
	}
	
	public static ConfigModel bulid() throws Exception {
		String defaultPath = "/config.xml";
		return bulid(defaultPath);
	}

}

三.案例

1.对web.xml进行建模

web.xml表代码块：

  
  	jrebelServlet
  	com.jiangwenjuan.xml.JrebelServlet
  
  
  
  	jrebelServlet
  	/jrebelServlet
  
  
  
  	jrebelServlet2
  	com.jiangwenjuan.xml.JrebelServlet2
  
  
  
  	jrebelServlet2
  	/jrebelServlet2
  	/jrebelServlet3
  

2.写一个servlet

3.通过url-pattern读取到servlet-class的值

ServletClassModel表：

package com.jiangwenjuan.serlvet;

public class ServletClassModel {
	//没有属性，有文本内容
//	com.jiangwenjuan.xml.JrebelServlet2
		private String context;

		public String getContext() {
			return context;
		}

		public void setContext(String context) {
			this.context = context;
		}


}

ServletMappingModel表：

package com.jiangwenjuan.serlvet;

import java.util.ArrayList;
import java.util.List;

public class ServletMappingModel {
	private ServletNameModel servletNameModel;
	private List urlPatternModels = new ArrayList<>();
	public ServletNameModel getServletNameModel() {
		return servletNameModel;
	}
	public void setServletNameModel(ServletNameModel servletNameModel) {
		this.servletNameModel = servletNameModel;
	}
	
	public void pushUrlPatternModel(UrlPatternModel urlPatternModel) {
		urlPatternModels.add(urlPatternModel);
	}
	
	public List getUrlPatternModels() {
		return urlPatternModels;
	}

}

ServletModel表：

package com.jiangwenjuan.serlvet;

public class ServletModel {
	private ServletNameModel servletNameModel;
	private ServletClassModel servletClassModel;

	public ServletNameModel getServletNameModel() {
		return servletNameModel;
	}

	public void setServletNameModel(ServletNameModel servletNameModel) {
		this.servletNameModel = servletNameModel;
	}

	public ServletClassModel getServletClassModel() {
		return servletClassModel;
	}

	public void setServletClassModel(ServletClassModel servletClassModel) {
		this.servletClassModel = servletClassModel;
	}

	
	
	
	

}

ServletNameModel表：

package com.jiangwenjuan.serlvet;

public class ServletNameModel {
	//没有属性，有文本内容
//	jrebelServlet2
	private String context;

	public String getContext() {
		return context;
	}

	public void setContext(String context) {
		this.context = context;
	}
	

}

UrlPatternModel表：

package com.jiangwenjuan.serlvet;

public class UrlPatternModel {
	//没有属性，有文本内容
//	jrebelServlet2
	private String context;

	public String getContext() {
		return context;
	}

	public void setContext(String context) {
		this.context = context;
	}
	
	

}

WebAppModel表:

package com.jiangwenjuan.serlvet;

import java.util.ArrayList;
import java.util.List;

public class WebAppModel {
	private List servletModels = new ArrayList<>();
	private List servletMappingModels = new ArrayList<>();

	public void pushServletModel(ServletModel servletModel) {
		servletModels.add(servletModel);
	}
	
	public List getServletModels() {
		return servletModels;
	}
	
	public void pushServletMappingModel(ServletMappingModel servletMappingModel) {
		servletMappingModels.add(servletMappingModel);
	}
	
	public List getServletMappingModels() {
		return servletMappingModels;
	}

}

WebAppModelFactory表:

package com.jiangwenjuan.serlvet;

import java.io.InputStream;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;


public class WebAppModelFactory {
	
	public static WebAppModel bulid() throws Exception  {
		String xmlPath = "/web.xml";
		return bulid(xmlPath);
	}
	
	
	public static WebAppModel bulid(String path) throws Exception {
		InputStream in = WebAppModelFactory.class.getResourceAsStream(path);
		SAXReader sr = new SAXReader();
		WebAppModel webAppModel = new WebAppModel();
		Document doc = sr.read(in);
		//拿到所有的内容
		List servletEles = doc.selectNodes("/web-app/servlet");
		for (Element serlvetEle : servletEles) {
			ServletModel selvetModel = new ServletModel();
			
			Element servletnameEle = (Element)serlvetEle.selectSingleNode("servlet-name");
			Element serlvetclassEle = (Element)serlvetEle.selectSingleNode("servlet-class");
			ServletNameModel servletNameModel = new ServletNameModel();
			ServletClassModel servletClassModel = new ServletClassModel();
			servletNameModel.setContext(servletnameEle.getText());
			servletClassModel.setContext(serlvetclassEle.getText());
			
			selvetModel.setServletClassModel(servletClassModel);
			selvetModel.setServletNameModel(servletNameModel);
			
			webAppModel.pushServletModel(selvetModel);
			
		}
		
		
		List servletmappingEles = doc.selectNodes("/web-app/serlvet-mapping");
		for (Element serlvetmappingEle : servletmappingEles) {
			ServletMappingModel servletMappingModel = new ServletMappingModel();
			
			
			Element servletnameEle = (Element)serlvetmappingEle.selectSingleNode("servlet-name");
			ServletNameModel servletNameModel = new ServletNameModel();
			servletNameModel.setContext(servletnameEle.getText());
			
			List urlpatternEles = serlvetmappingEle.selectNodes("url-pattern");
			for (Element urlpatternEle : servletmappingEles) {
				UrlPatternModel urlPatternModel = new UrlPatternModel();
				urlPatternModel.setContext(urlpatternEle.getText());
				servletMappingModel.pushUrlPatternModel(urlPatternModel);
			}
			webAppModel.pushServletMappingModel(servletMappingModel);
		}
		
		return webAppModel;
	}
	
	
	public static String getServletClassByUrl(WebAppModel webAppModel,String url) {
		String servletClass = "";
		
		String servletName = "";
		List servletMappingModels = webAppModel.getServletMappingModels();
		for (ServletMappingModel servletMappingModel : servletMappingModels) {
			List urlPatternModels = servletMappingModel.getUrlPatternModels();
			for (UrlPatternModel urlPatternModel : urlPatternModels) {
				if(url.equals(urlPatternModel.getContext())) {
					ServletNameModel servletNameModel = new ServletNameModel();
					servletName = servletNameModel.getContext();
				}
			}
		}
		
		
		List servletModels = webAppModel.getServletModels();
		for (ServletModel servletModel : servletModels) {
			ServletNameModel servletNameModel = servletModel.getServletNameModel();
			if(servletName.equals(servletNameModel.getContext())) {
				ServletClassModel servletClassModel = servletModel.getServletClassModel();
				servletClass = servletClassModel.getContext();
			}
		}
		return servletClass;
		
	}
	
	public static void main(String[] args) throws Exception {
		WebAppModel webAppModel = WebAppModelFactory.bulid();
		String res = getServletClassByUrl(webAppModel, "/jrebelServlet");
		String res2 = getServletClassByUrl(webAppModel, "/jrebelServlet2");
		String res3 = getServletClassByUrl(webAppModel, "/jrebelServlet3");
		System.out.println(res);
		System.out.println(res2);
		System.out.println(res3);
	}
	

}

最终结果：