XML建模_xml生成3d模型-优快云博客

本文链接：https://blog.youkuaiyun.com/m0_63579794/article/details/125182817

该博客介绍了XML建模的概念，通过DOM4J和XPath技术解析XML配置文件，将XML元素转换为对象模型。文章以一个具体的配置文件为例，展示了如何创建ConfigModel、ActionModel和ForwardModel实体类，并利用工厂模式进行建模。此外，还详细阐述了XML文档的DTD约束和建模过程。

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一.什么叫XML建模

将XML配置文件中的元素、属性、文本信息转换成对象的过程叫做XML建模

二. XML建模

1）根据XML配置文件元素节点创建元素节点实体类
ConfigModel、ActionModel、ForwardModel
2）利用dom4j+xpath技术实现XML建模
ConfigModelFactory

2.0 config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- config标签:可以包含0~N个action标签 -->
<!DOCTYPE config [
       <!ELEMENT config (action*)>
       <!ELEMENT action (forward*)>
       
       <!ATTLIST action
          path CDATA "/"
          type CDATA #REQUIRED
       >
      <!ATTLIST forward
          name CDATA #REQUIRED 
          path CDATA "/"
          redirect (false|true) "false"
       >
      
    ]>

<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>

2.1 ActionModel类

package com.zking.XMLModel.entity;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

/**
 * ActionModel实体类对应config.xml中action节点
 * 
 * @author Administrator
 *
 */
public class ActionModel implements Serializable {

	private String path;
	private String type;
    
	//key:代表forward节点的name属性,唯一
	//value:代表整合forward对象所对应的建模实体类ForwardModel
	private Map<String,ForwardModel> forwards=new HashMap<>();
	
	/**
	 * 取值方法
	 * @param name
	 * @return
	 */
	public ForwardModel get(String name) {
		return forwards.get(name);
	}
	
	/**
	 * 存值方法
	 * @param forward 根据forward的name属性作为key,forward对象
	 */
	public void push(ForwardModel forward) {
		forwards.put(forward.getName(), forward);
	}
	
	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;
	}

}

2.2 ConfigModel类

package com.zking.XMLModel.entity;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

/**
 * ConfigModel实体类对应config.xml中config节点
 * @author Administrator
 *
 */
public class ConfigModel implements Serializable{

	//key:代表action节点的path属性,唯一
	//value:代表action节点所对应的建模实体类ActionModel
	private Map<String,ActionModel> actions=new HashMap<>();
	
	/**
	 * 取值方法
	 * @param path
	 * @return
	 */
	public ActionModel get(String path) {
		return actions.get(path);
	}
	
	/**
	 * 存值方法
	 * @param action 根据action中的path属性作为key,以整个action节点作为value值
	 */
	public void push(ActionModel action) {
		actions.put(action.getPath(), action);
	}
	
}

2.3 ForWordModel类

package com.zking.XMLModel.entity;

import java.io.Serializable;

/**
 * ForwartModel实体类对应config.xml中forward标签
 * 
 * @author Administrator
 *
 */
public class ForwardModel implements Serializable {

	// name属性对应config.xml中forward节点的name属性
	private String name;
	// name属性对应config.xml中forward节点的path属性
	private String path;
	// name属性对应config.xml中forward节点的redirect属性
	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;
	}

	@Override
	public String toString() {
		return "ForwardModel [name=" + name + ", path=" + path + ", redirect=" + redirect + "]";
	}

}

2.4 ConfigModelFactory类

package com.zking.XMLModel.util;

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;

import com.zking.XMLModel.entity.ActionModel;
import com.zking.XMLModel.entity.ConfigModel;
import com.zking.XMLModel.entity.ForwardModel;

public class ConfigModelFactory {

	// 默认配置文件路径
	public static final String DEFAULT_PATH = "/config.xml";

	public ConfigModelFactory() {

	}
    
	public static ConfigModel createConfigModel() {
		return createConfigModel(DEFAULT_PATH);
	}

	public static ConfigModel createConfigModel(String path) {

		ConfigModel configModel = new ConfigModel();
		ActionModel actionModel = null;
		ForwardModel forwardModel = null;

		try {
			// 1.获取文件输入流
			InputStream is = ConfigModelFactory.class.getResourceAsStream(path);
			// 2.创建SAXReader对象
			SAXReader saxReader = new SAXReader();
			// 3.读取文件 输入流并转换成Document对象
			Document doc = saxReader.read(is);
			// 4.解析XML文件
			// 获取多个节点:selectNodes
			// 获取单个节点:selectSingleNode
			// xpath语法: / 代表定位路径 @ 代表获取属性
			List<Node> actionNodes = doc.selectNodes("/config/action");
			// 循环遍历action节点
			for (Node action : actionNodes) {
				// 5.将action节点转换成元素节点
				Element actionElem = (Element) action;
				// 6.逐一获取action节点中的属性(path和type)
				String actionpath = actionElem.attributeValue("path");
				String actionType = actionElem.attributeValue("type");
				// 7.初始化ActionModel并完成建模赋值操作
				actionModel = new ActionModel();
				actionModel.setPath(actionpath);
				actionModel.setType(actionType);
				// 8.获取action节点下的forward节点(0-N个)
				List<Node> forwardNodes = actionElem.selectNodes("forward");
				// 9.循环遍历所有的forward节点
				for (Node forward : forwardNodes) {
					// 10.将forward节点转换成元素节点
					Element forwardElem = (Element) forward;
					// 11.获取forward节点所有属性(name.path和redirect)
					String forwardName = forwardElem.attributeValue("name");
					String forwardPath = forwardElem.attributeValue("path");
					String forwardRedirect = forwardElem.attributeValue("redirect");
					// 12.创建forwardModel建模对象并完成赋值操作
					forwardModel = new ForwardModel();
					forwardModel.setName(forwardName);
					forwardModel.setPath(forwardPath);
					forwardModel.setRedirect(Boolean.parseBoolean(forwardRedirect));
					// 13.action节点中包含0-N个forward节点
					actionModel.push(forwardModel);
				}
				// 14.config节点中包含0-N个action节点
				configModel.push(actionModel);
			}
		} catch (DocumentException e) {
			e.printStackTrace();
		}
		return configModel;
	}

	public static void main(String[] args) {
		ConfigModel createConfigModel = ConfigModelFactory.createConfigModel();

		ActionModel actionModel = createConfigModel.get("/regAction");
		System.out.println("action节点path属性:" + actionModel.getPath());
		System.out.println("action节点type属性:" + actionModel.getType());
		System.out.println("-----------------------------------------");
		ForwardModel forwardModel = actionModel.get("failed");
		System.out.println("forward节点name属性:" + forwardModel.getName());
		System.out.println("forward节点path属性:" + forwardModel.getPath());
		System.out.println("forward节点redirect属性:" + forwardModel.isRedirect());
	}

}

DTD约束：由XML的根节点往里建立约束
XML建模：由最里层节点往根节点进行建模，一个元素节点代表一个实体类

思路：
1）xml文件config.xml

2）根据XML中元素节点情况（DTD）来定义ConfigModel、ActionModel、ForwardModel对象模型

A.config节点下有多个子action节点，无节点属性
B.action节点下有多个子forward节点，有节点属性
C.forward下无子节点，有节点属性

3）使用Map集合存放子节点元素，其中key为子节点唯一属性，value为整个子节点对象

4）利用工厂模式+dom4j+xpath解析Xml配置文件