本节知识总结：
一、建模由来
建模的由来：将指定的xml字符串当做对象来操作
二、建模思路
思路：
1.要分析需要被建模的文件中有哪几个对象
2.每个对象拥有的行为以及属性
3.定义一个从里到外的对象
4.通过23重设计模式中的工厂模式，解析xml生产指定对象
作用：提高代码反复使用性??
建模方式：由内到外
根据上面思路我们可以通过一个小案例来解析~?
三、建模步骤
1.以面向对象的编程思想，描述xml资源文件
2.将xml文件中的内容封装到model实体对象中
通过案例config.xml解析
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE config[
?? ?<!ELEMENT config (action*)>
?? ?<!ELEMENT action (forward*)>
?? ?<!ELEMENT forward EMPTY>
?? ?<!ATTLIST action
?? ? ?path CDATA #REQUIRED
?? ? ?type CDATA #REQUIRED
?? ?>
?? ?<!ATTLIST forward
?? ? ?name CDATA #REQUIRED
?? ? ?path CDATA #REQUIRED
?? ? ?redirect (true|false) "false"
?? ?>
]>
<!-- config标签:可以包含0~N个action标签 -->
<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" redirect="true" />
?? ?</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>
👍根据思路分析config文件
1.要分析需要被建模的文件中有哪几个对象
①config对象②action对象③forward对象
2.每个对象拥有的行为以及属性
在action中有增加（压栈）和获得（弹栈）
3.定义一个从里到外的对象
先forward>action>config
4.通过23重设计模式中的工厂模式，解析xml生产指定对象
分别建立ForwardModel、ActionModel、ConfigModel? ? ? ?
建立工厂：ConfigModelFactory
ForwardModel类：
package com.xiehuiyi.xml;
public class ForwardModel {
/**
* 建模方式：由内到外
*/
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类：
package com.xiehuiyi.xml;
/**
* 在actionmodel里面有增加，获得（查找）
* @author zjjt
*
*/
import java.util.HashMap;
import java.util.Map;
public class ActionModel {
private String path;
private String type;
private Map<String, ForwardModel> fMap=new HashMap<String, ForwardModel>();
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;
}
//增加，压栈
public void push(ForwardModel forwardModel) {
fMap.put(forwardModel.getName(), forwardModel);
}
//弹栈
public ForwardModel pop(String name) {
return fMap.get(name);
}
}
ConfigModel类：?
package com.xiehuiyi.xml;
import java.util.HashMap;
import java.util.Map;
public class ConfigModel {
private Map<String, ActionModel> acMap=new HashMap<String, ActionModel>();
//压栈
public void push(ActionModel actionModel) {
acMap.put(actionModel.getPath(), actionModel);
}
//弹栈
public ActionModel pop(String path) {
return acMap.get(path);
}
public static void main(String[] args) throws Exception {
//此时config没值 建模
// ConfigModel configModel=new ConfigModel();
ConfigModel configModel=ConfigModelFactory.build();
//案例：2.获得第二个action中的type的值
ActionModel actionModel=configModel.pop("/loginAction");
System.out.println(actionModel.getType());
ForwardModel forwardModel = actionModel.pop("success");
//3.获得第二个action中所有forword的path的值
//
//4.获得第二个action中第二个forword的path的值
}
}
ConfigModelFactory类：
package com.xiehuiyi.xml;
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;
/**
* 建模的思路：
* 1.将原有的config.xml进行解析
* 2.对应标签的内容，将其封装赋值给相应的对象
* 。。。。。。
* @author zjjt
*
*/
public class ConfigModelFactory {
public static ConfigModel build() throws Exception {
return build("config.xml");
}
public static ConfigModel build(String resourcepath) throws Exception {
InputStream in = ConfigModelFactory.class.getResourceAsStream(resourcepath);
SAXReader saxReader=new SAXReader();
Document doc=saxReader.read(in);
ConfigModel configModel=new ConfigModel();
List<Element> actionEles=doc.selectNodes("/config/action");
for (Element actionEle : actionEles) {
ActionModel actionModel=new ActionModel();
//将xml文件解析得来的path赋值给actionModel
actionModel.setPath(actionEle.attributeValue("path"));
actionModel.setType(actionEle.attributeValue("type"));
List<Element> forwardEles=actionEle.selectNodes("forward");
for (Element forwardEle : forwardEles) {
ForwardModel forwardModel=new ForwardModel();
forwardModel.setName(forwardEle.attributeValue("name"));
forwardModel.setPath(forwardEle.attributeValue("path"));
//Redirect只有在配置文件中赋值false的时候，代表转发，其代表重定向
forwardModel.setRedirect(!"false".equals(forwardEle.attributeValue("redirect")));
actionModel.push(forwardModel);
}
configModel.push(actionModel);
}
return configModel;
}
}
练习：?
案例解析web.xml😀
<?xml version="1.0" encoding="UTF-8"?>
<web-app>//根对象
? <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>
?*用上面思路分析得知对象有：红色字体
建包：
ServletNameModel类：
package com.xiehuiyi.xml1;
public class ServletNameModel {
private String context;
public String getContext() {
return context;
}
public void setContext(String context) {
this.context = context;
}
}
ServletClass类：
package com.xiehuiyi.xml1;
public class ServletClassModel {
private String context;
public String getContext() {
return context;
}
public void setContext(String context) {
this.context = context;
}
}
UrlPatternModel类：
package com.xiehuiyi.xml1;
public class UrlPatternModel {
private String context;
public String getContext() {
return context;
}
public void setContext(String context) {
this.context = context;
}
}ServletModel类：
package com.xiehuiyi.xml1;
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;
}
}
ServletMappingModel类：
package com.xiehuiyi.xml1;
import java.util.ArrayList;
import java.util.List;
public class ServletMappingModel {
private ServletNameModel servletNameModel;
private List<UrlPatternModel> urlPatternModels = new ArrayList<UrlPatternModel>();
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类：
package com.xiehuiyi.xml1;
import java.util.ArrayList;
import java.util.List;
public class WebAppModel {
private List<ServletModel> servletModels = new ArrayList<ServletModel>();
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;
}
}
?工厂类WebAppModelFactory类：
package com.xiehuiyi.xml1;
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
*
*/
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.setservletclass(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
*
*/
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;
}
}
测试：
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);
}总结
XML建模就是利用工厂模式+dom4j+xpath解析Xml配置文件
以上内容就是今天全部内容，希望能够帮到你，今天内容就在这了！我们下期再见！