XML建模

• 1.建模的由来
  就是将指定的xml字符串当作对象来操作。
  如果说当对一个指定的xml格式字符串完成了建模操作，
  好处在于，只需要调用指定的方法就可以完成预定的字符串获取；

• 2.建模的思路
  (1)、分析需要被建模的文件中有那几个对象
  (2)、每个对象拥有的行为以及属性
  (3)、定义对象从小到大（从里到外）
  (4)、通过23种的设计模式中的工厂模式，解析xml生产出指定对象
  好处：
  提高代码的复用性

• 3.XML建模
  根据XML配置文件元素节点创建元素，节点，实体类
  ConfigModel（查找 新增）
  ActionModel （属性 新增 查询）
  ForwardModel（属性）
  利用dom4j+xpath技术实现XML建模ConfigModelFactory（提高代码的复用性）

• 4.建模分两步：
  (1)、以面向对象的编程思想，描述xml资源文件
  (2)、将xml文件中内容封装进model实体对象。

对mvc.xml文件进行建模

• mvc.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<config>
 <!-- action标签:可以饱含0~N个forward标签 path:以/开头的字符串,并且值必须唯一 非空 type:字符串,非空 -->
 <action path="/regAction" type="test.RegAction">
  <!-- forward标签:没有子标签; name:字符串,同一action标签下的forward标签name值不能相同 ; path:以/开头的字符串 
   redirect:只能是false|true,允许空,默认值为false -->
  <forward name="failed" path="/reg.jsp" redirect="false" />
  <forward name="success" path="/login.jsp" />
 </action>
 <action path="/loginAction" type="test.LoginAction">
  <forward name="failed" path="/login.jsp" redirect="false" />
  <forward name="success" path="/main.jsp" redirect="true" />
 </action>
</config>

• ForwardModel

package com.cjq.model;
public class ForwardModel {
  private String name;
  private  String path;
  private  boolean redirect = true;
  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

package com.cjq.model;
import java.util.HashMap;
import java.util.Map;public class ActionModel {
 private String path;
 private String type;
 private Map<String, ForwardModel> 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;
 }
 /**
  * 压栈 
  * @param cjq
  */
 public void push(ForwardModel forwardModel) {
  fMap.put(forwardModel.getName(), forwardModel);
 }
 /**
  * 弹栈
  * @return cjq
  */
 public ForwardModel pop(String name) {
  return fMap.get(name);
 }
 
}

• ConfigModel

package com.cjq.model;
import java.util.HashMap;
import java.util.Map;public class ConfigModel {
 private Map<String, ActionModel> aMap=new HashMap<>();
 /**
  * 压栈
  * @author cjq
  *
  */
 public void push(ActionModel actionModel) {
  aMap.put(actionModel.getPath(), actionModel);
 }
 
 /**
  * 弹栈
  * @return cjq
  *
  */
 public ActionModel pop(String path) {
  return aMap.get(path);
 }
 
}

• ConfigModelFactory

package com.cjq.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;/**
 *  java中有23中设计模式
 *  工厂模式：
 *   why:能够提高代码的复用性
 *   how:只要建立一个方法，去生产指定的你需要的对象
 *   where:去生产指定的你需要的对象，以便重复使用
 * 
 * @author cjq
 *
 */public class ConfigModelFactory {
 /**
  *  默认资源文件mvc.xml是放在建模类的同包下
  * @return
  * @throws DocumentException
  */
 public static ConfigModel build() throws DocumentException{
  return build("mvc.xml");
 }
 
 /**
  * 当资源文件，需要手动改变位置的情况下，那么需要调以下方法
  * @param xmlPath
  * @return
  * @throws DocumentException
  */
 public static ConfigModel build(String xmlPath) throws DocumentException{
  ConfigModel configModel=new ConfigModel();
  ActionModel actionModel=null;
  ForwardModel forwardModel=null;
  
  InputStream in=ConfigModelFactory.class.getResourceAsStream(xmlPath);
  SAXReader reader=new SAXReader();
  Document doc=reader.read(in);
  List<Element> actionEles=doc.selectNodes("config/action");
  for (Element actionEle : actionEles) {
   actionModel=new ActionModel();
//   填充actionModel
   actionModel.setPath(actionEle.attributeValue("path"));
   actionModel.setType(actionEle.attributeValue("type"));
  
  
      List<Element> forwardEles=actionEle.selectNodes("forward");
      for (Element forwardEle : forwardEles) {
       forwardModel=new ForwardModel();
//    填充forwardModel
       forwardModel.setName(forwardEle.attributeValue("name"));
       forwardModel.setPath(forwardEle.attributeValue("path"));
       forwardModel.setRedirect("false".equals(forwardEle.attributeValue("redirect")));
       actionModel.push(forwardModel);
      }
  configModel.push(actionModel);
  }
  return configModel;
 }
 
 public static void main(String[] args) throws DocumentException {
  ConfigModel configModel=ConfigModelFactory.build();
  ActionModel actionModel=configModel.pop("/loginAction");
  System.out.println(actionModel.getType());
  System.out.println(actionModel.pop("success").getPath());
 }}

运行结果如下：

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

• web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app>
  <servlet>
   <servlet-name>jrebelServlet</servlet-name>
   <servlet-class>com.zking.xml.JrebelServlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
   <servlet-name>jrebelServlet</servlet-name>
   <url-pattern>/jrebelServlet</url-pattern>
  </servlet-mapping>
  
  <servlet>
   <servlet-name>jrebelServlet2</servlet-name>
   <servlet-class>com.zking.xml.JrebelServlet2</servlet-class>
  </servlet>
  
  <servlet-mapping>
   <servlet-name>jrebelServlet2</servlet-name>
   <url-pattern>/jrebelServlet2</url-pattern>
   <url-pattern>/jrebelServlet3</url-pattern>
  </servlet-mapping>
</web-app>

• ServletNameModel

package com.cjq.zy;
public class ServletNameModel {
 private String context; public String getContext() {
  return context;
 } public void setContext(String context) {
  this.context = context;
 }
}

• ServletClassModel

package com.cjq.zy;
public class ServletClassModel {
 private String context; public String getContext() {
  return context;
 } public void setContext(String context) {
  this.context = context;
 }
}

• UrlPatternModel

package com.cjq.zy;
public class UrlPatternModel {
 private String context; public String getContext() {
  return context;
 } public void setContext(String context) {
  this.context = context;
 }}

• ServletModel

package com.cjq.zy;
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;
 }}

• ServletMappingModel

package com.cjq.zy;
import java.util.ArrayList;
import java.util.List;public class ServletMappingModel {
 private ServletNameModel servletNameModel;
 private List<UrlPatternModel> 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<UrlPatternModel> getUrlPatternModels() {
  return urlPatternModels;
 }
}

• WebAppModel

package com.cjq.zy;
import java.util.ArrayList;
import java.util.List;public class WebAppModel {
 private List<ServletModel> servletModels = new ArrayList<>();
 private List<ServletMappingModel> servletMappingModels = new ArrayList<>(); public void pushServletModel(ServletModel servletModel) {
  servletModels.add(servletModel);
 }
 
 public List<ServletModel> getServletModels() {
  return servletModels;
 }
 
 public void pushServletMappingModel(ServletMappingModel servletMappingModel) {
  servletMappingModels.add(servletMappingModel);
 }
 
 public List<ServletMappingModel> getServletMappingModels() {
  return servletMappingModels;
 }}

• WebAppModelFatory

package com.cjq.zy;
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 buildWebAppModel() {
  String xmlPath = "/web.xml";
  return buildWebAppModel(xmlPath);
 } /**
  * 建模
  * 
  * @param xmlPath
  * @return
  */
 public static WebAppModel buildWebAppModel(String xmlPath) {
  InputStream in = WebAppModelFactory.class.getResourceAsStream(xmlPath);
  SAXReader saxReader = new SAXReader();
  WebAppModel webAppModel = new WebAppModel();
  try {
   Document doc = saxReader.read(in);
   /*
    * 将servlet的标签内容填充进WebApp
    */
   List<Element> servletEles = doc.selectNodes("/web-app/servlet");
   for (Element servletEle : servletEles) {
    ServletModel servletModel = new ServletModel();    /*
     * 给ServletModel填充xml的内容
     */
    Element servletNameEle = (Element) servletEle.selectSingleNode("servlet-name");
    Element servletClassEle = (Element) servletEle.selectSingleNode("servlet-class");
    ServletNameModel servletNameModel = new ServletNameModel();
    ServletClassModel servletClassModel = new ServletClassModel();
    servletNameModel.setContext(servletNameEle.getText());
    servletClassModel.setContext(servletClassEle.getText());
    
    servletModel.setServletNameModel(servletNameModel);
    servletModel.setServletClassModel(servletClassModel);    webAppModel.pushServletModel(servletModel);
   }   /*
    * 将servlet-mapping的标签内容填充进WebApp
    */
   List<Element> servletMappingEles = doc.selectNodes("/web-app/servlet-mapping");
   for (Element servletMappingEle : servletMappingEles) {
    ServletMappingModel servletMappingModel = new ServletMappingModel();    /*
     * 给ServletMappingModel填充xml的内容
     */
    Element servletNameEle = (Element) servletMappingEle.selectSingleNode("servlet-name");
    ServletNameModel servletNameModel = new ServletNameModel();
    servletNameModel.setContext(servletNameEle.getText());
    servletMappingModel.setServletNameModel(servletNameModel);
    
    List<Element> urlPatternEles = servletMappingEle.selectNodes("url-pattern");
    for (Element urlPatternEle : urlPatternEles) {
     UrlPatternModel urlPatternModel = new UrlPatternModel();
     urlPatternModel.setContext(urlPatternEle.getText());
     servletMappingModel.pushUrlPatternModel(urlPatternModel);
    }    webAppModel.pushServletMappingModel(servletMappingModel);
   }  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return webAppModel;
 }
 
 /**
  * 通过浏览器输入的网址自动找到对应的后台处理类
  * @param webAppModel 建模后的实体类
  * @param url 浏览器访问的网址
  * @return
  */
 public static String getServletClassByUrl(WebAppModel webAppModel, String url) {
  String servletClass = "";
  /*
   * 找到浏览器网址对应的servlet-name
   */
  String servletName = "";
  List<ServletMappingModel> servletMappingModels = webAppModel.getServletMappingModels();
  for (ServletMappingModel servletMappingModel : servletMappingModels) {
   List<UrlPatternModel> urlPatternModels = servletMappingModel.getUrlPatternModels();
   for (UrlPatternModel urlPatternModel : urlPatternModels) {
    if(url.equals(urlPatternModel.getContext())) {
     ServletNameModel servletNameModel = servletMappingModel.getServletNameModel();
     servletName = servletNameModel.getContext();
    }
   }
  }
  
  /*
   * 找到servlet-name对应的后台处理类
   */
  List<ServletModel> 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) {
  WebAppModel webAppModel = WebAppModelFactory.buildWebAppModel();
  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);
  
 }
}

运行结果如下：