• XML建模

    目录

    一、xml建模核心思想

    二、xml建模的作用

    三、建模案例

    ConfigModel类

    ActionModel类

    自定义异常

    ForwardModel类

    自定义异常

    ConfigFactory类

    测试

    一、xml建模核心思想

    xml建模的核心思想就是利用java面向对象的特性，用操作对象的方式操作xml。

    二、xml建模的作用

    1、节约资源

    2、优化性能

    3、更加便捷操作xml文件

    三、建模案例

    以下方config.xml为例

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <!DOCTYPE config[
    3. 	<!ELEMENT config (action*)>
    4. 	<!ELEMENT action (forward*)>
    5. 	<!ELEMENT forward EMPTY>
    6. 	<!ATTLIST action
    7. 	  path CDATA #REQUIRED
    8. 	  type CDATA #REQUIRED
    9. 	>
    10. 	<!ATTLIST forward
    11. 	  name CDATA #REQUIRED
    12. 	  path CDATA #REQUIRED
    13. 	  redirect (true|false) "false"
    14. 	>
    15. ]>
    16. <config>
    17. 	<action path="/studentAction" type="org.lisen.mvc.action.StudentAction">
    18. 		<forward name="students" path="/students/studentList.jsp" redirect="false"/>
    19. 	</action>
    20. </config>
    • 一个标签就是一个对象，在上方xml文件中有三个标签config、action、forward。所以我们需要三个实体类来进行建模

    ConfigModel类

    在集合中增加ActionModel对象，通过path找到对应的ActionModel对象

    1. package com.zking.mymvc.framework;
    2.  
    3. import java.util.HashMap;
    4. import java.util.Map;
    5.  
    6. public class ConfigModel {
    7.  
    8. 	private Map<String, ActionModel> actionMap=new HashMap<String, ActionModel>();
    9. 	
    10.  
    11. 	/**
    12. 	 * 将ActionModel对象放到map集合
    13. 	 * @param forward
    14. 	 */
    15. 	public void put(ActionModel action) {
    16. 		if(actionMap.containsKey(action.getPath())) {
    17. 			throw new ActionDuplicateDefinitionException("Action path ="+ action.getPath()+" duplicate definition");
    18. 		}
    19. 		actionMap.put(action.getPath(), action);
    20. 	}
    21. 	
    22. 	/**
    23. 	 * 通过action中的path从map结合中取出对应的action对象 若path填错则抛出自定义异常未找到
    24. 	 * @param name
    25. 	 * @return
    26. 	 */
    27. 	public ActionModel find(String path) {
    28. 		if(!actionMap.containsKey(path)) {
    29. 		throw new ActionNotFoundException("Action path ="+ path +" not found");
    30. 	}
    31. 		return actionMap.get(path);
    32. 	}
    33.  
    34. 	@Override
    35. 	public String toString() {
    36. 		return "ConfigModel [actionMap=" + actionMap + "]";
    37. 	}
    38. 	
    39. 	
    40. }

    ActionModel类

    在集合中增加ForwardModel对象，通过path找到对应的ForwardModel对象

    1. package com.zking.mymvc.framework;
    2.  
    3. import java.util.HashMap;
    4. import java.util.Map;
    5.  
    6. public class ActionModel {
    7.  
    8. 	private String path;
    9. 	private String type;
    10. 	private Map<String, ForwardModel> forwardMap=new HashMap<String, ForwardModel>();
    11. 	public String getPath() {
    12. 		return path;
    13. 	}
    14. 	public void setPath(String path) {
    15. 		this.path = path;
    16. 	}
    17. 	public String getType() {
    18. 		return type;
    19. 	}
    20. 	public void setType(String type) {
    21. 		this.type = type;
    22. 	}
    23. 	public Map<String, ForwardModel> getForwardMap() {
    24. 		return forwardMap;
    25. 	}
    26. 	public void setForwardMap(Map<String, ForwardModel> forwardMap) {
    27. 		this.forwardMap = forwardMap;
    28. 	}
    29. 	
    30. 	/**
    31. 	 * 将forwardModel对象放到map集合
    32. 	 * @param forward
    33. 	 */
    34. 	public void put(ForwardModel forward) {
    35. 		if(forwardMap.containsKey(forward.getName())) {
    36. 			throw new ForwardDuplicateDefinitionException("forward name= "+forward.getName()+"duplicate definition");
    37. 			
    38. 		}
    39. 		forwardMap.put(forward.getName(), forward);
    40. 	}
    41. 	
    42. 	/**
    43. 	 * 通过forward中的name从map结合中取出对应的forward对象 若name填错则抛出自定义异常未找到
    44. 	 * @param name
    45. 	 * @return
    46. 	 */
    47. 	public ForwardModel find(String name) {
    48. 		if(!forwardMap.containsKey(name)) {
    49. 			throw new ForwardNotFoundException("Forward name ="+name+" not found");
    50. 		}
    51. 		return forwardMap.get(name);
    52. 	}
    53. 	@Override
    54. 	public String toString() {
    55. 		return "ActionModel [path=" + path + ", type=" + type + ", forwardMap=" + forwardMap + "]";
    56. 	}
    57. 	
    58. 	
    59. }

    自定义异常

    • action重复定义
    1. package com.zking.mymvc.framework;
    2.  
    3. public class ActionDuplicateDefinitionException extends RuntimeException{
    4.  
    5. 	public ActionDuplicateDefinitionException() {
    6. 		super();
    7. 	}
    8. 	/**
    9. 	 * 报错信息
    10. 	 * @param msg
    11. 	 */
    12. 	public ActionDuplicateDefinitionException(String msg) {
    13. 		super(msg);
    14. 	}
    15. 	/**
    16. 	 * 报错信息、报错原因
    17. 	 * @param msg
    18. 	 * @param c
    19. 	 */
    20. 	public ActionDuplicateDefinitionException(String msg,Throwable c) {
    21. 		super(msg,c);
    22. 	}
    23. 	
    24. }
    •  action的path找不到
    1. package com.zking.mymvc.framework;
    2.  
    3. public class ActionNotFoundException extends RuntimeException {
    4.  
    5. 	public ActionNotFoundException() {
    6. 		super();
    7. 	}
    8. 	/**
    9. 	 * 报错信息
    10. 	 * @param msg
    11. 	 */
    12. 	public ActionNotFoundException(String msg) {
    13. 		super(msg);
    14. 	}
    15. 	/**
    16. 	 * 报错信息、报错原因
    17. 	 * @param msg
    18. 	 * @param c
    19. 	 */
    20. 	public ActionNotFoundException(String msg,Throwable c) {
    21. 		super(msg,c);
    22. 	}
    23. 	
    24. }

    ForwardModel类

    1. package com.zking.mymvc.framework;
    2.  
    3. public class ForwardModel {
    4.  
    5. 	private String name;
    6. 	private String path;
    7. 	private boolean redirect;
    8. 	public String getName() {
    9. 		return name;
    10. 	}
    11. 	public void setName(String name) {
    12. 		this.name = name;
    13. 	}
    14. 	public String getPath() {
    15. 		return path;
    16. 	}
    17. 	public void setPath(String path) {
    18. 		this.path = path;
    19. 	}
    20. 	public boolean isRedirect() {
    21. 		return redirect;
    22. 	}
    23. 	public void setRedirect(boolean redirect) {
    24. 		this.redirect = redirect;
    25. 	}
    26. 	
    27. 	public void setRedirect(String redirect) {
    28. 		this.redirect = Boolean.valueOf(redirect);
    29. 	}
    30. 	@Override
    31. 	public String toString() {
    32. 		return "ForwardModel [name=" + name + ", path=" + path + ", redirect=" + redirect + "]";
    33. 	}
    34. 	
    35. 	
    36. 	
    37. }

    自定义异常

    • forward重复定义
    1. package com.zking.mymvc.framework;
    2.  
    3. public class ForwardDuplicateDefinitionException extends RuntimeException{
    4.  
    5. 	public ForwardDuplicateDefinitionException() {
    6. 		super();
    7. 	}
    8. 	/**
    9. 	 * 报错信息
    10. 	 * @param msg
    11. 	 * 
    12. 	 */
    13. 	public ForwardDuplicateDefinitionException(String msg) {
    14. 		super(msg);
    15. 	}
    16. 	/**
    17. 	 * 报错信息、报错原因
    18. 	 * @param msg
    19. 	 * @param c
    20. 	 */
    21. 	public ForwardDuplicateDefinitionException(String msg,Throwable c) {
    22. 		super(msg,c);
    23. 	}
    24. 	
    25. }
    • forward中的name找不到
    1. package com.zking.mymvc.framework;
    2.  
    3. public class ForwardNotFoundException extends RuntimeException {
    4.  
    5. 	public ForwardNotFoundException() {
    6. 		super();
    7. 	}
    8. 	/**
    9. 	 * 报错信息
    10. 	 * @param msg
    11. 	 */
    12. 	public ForwardNotFoundException(String msg) {
    13. 		super(msg);
    14. 	}
    15. 	/**
    16. 	 * 报错信息、报错原因
    17. 	 * @param msg
    18. 	 * @param c
    19. 	 */
    20. 	public ForwardNotFoundException(String msg,Throwable c) {
    21. 		super(msg,c);
    22. 	}
    23. 	
    24. }
    • 当三个都完成后，将他们装到ConfigModel中去，需要建一个ConfigFactory类

    ConfigFactory类

    1. package com.zking.mymvc.framework;
    2.  
    3. import java.io.InputStream;
    4. import java.util.List;
    5.  
    6.  
    7. import org.dom4j.Document;
    8. import org.dom4j.Element;
    9. import org.dom4j.io.SAXReader;
    10. import org.xml.sax.XMLReader;
    11.  
    12. @SuppressWarnings("unchecked")
    13. public final class ConfigModelFactory {
    14.  
    15. 	private ConfigModelFactory() {
    16. 		
    17. 	}
    18. 	
    19. 	private static ConfigModel config=new ConfigModel();
    20. 	
    21. 	//进行读取config.xml中的数据填充到模型中
    22. 	static {
    23. 		try {
    24. 			//1.获取io流
    25. 			InputStream in = XMLReader.class.getResourceAsStream("/config.xml");
    26. 		    //2.创建xml读取工具类SAXReader
    27. 			SAXReader sax = new SAXReader();
    28. 		    //3.读取配置文件，获得Document对象
    29. 			Document doc = sax.read(in);
    30. 		    //获取根元素
    31. 		    Element rootElement = doc.getRootElement();
    32. 		    //找到action节点
    33. 		    List<Element> actions = rootElement.selectNodes("action");
    34. 	        for(Element e: actions) {
    35. 	        	//获取属性值
    36. 	        	String path = e.attributeValue("path");
    37. 	            String type = e.attributeValue("type");
    38. 	            //实例化ActionModel对象
    39. 	            ActionModel action = new ActionModel();
    40. 	           //将属性值放到ActionModel中
    41. 	            action.setPath(path);
    42. 	            action.setType(type);
    43. 	            //找到forward节点
    44. 	            List<Element> forwards = e.selectNodes("forward");
    45. 	           for(Element f: forwards) {
    46. 	        	 //获取属性值
    47. 	        	   String name = f.attributeValue("name");
    48. 	               String fpath = f.attributeValue("path");
    49. 	               String redirect = f.attributeValue("redirect");
    50. 	               //实例化ForwardModel对象
    51. 	                ForwardModel forward = new ForwardModel();
    52. 	               //将属性值放入ForwardModel对象中去
    53. 	                forward.setName(name);
    54. 	               forward.setPath(fpath);
    55. 	               forward.setRedirect(redirect);
    56. 	               //将ForwardModel放到ActionModel集合中去
    57. 	              action.put(forward);   
    58. 	           }
    59. 	         //将ActionModel放到集合中去ConfigModel
    60. 	           config.put(action);
    61. 	        }
    62. 		} catch (Exception e) {
    63. 			e.printStackTrace();
    64. 		}
    65.         
    66. 	}
    67. 	
    68. 	public static ConfigModel getConfig() {
    69. 		return config;
    70. 	}
    71. 	
    72. 	
    73. }

    • 测试

    1. package com.zking.mymvc.framework;
    2.  
    3. public class Test {
    4. public static void main(String[] args) {
    5. 		ConfigModel config=ConfigModelFactory.getConfig();
    6. 	  ActionModel action = config.find("/studentAction");
    7. 	  System.out.println(action);
    8. 	  ForwardModel forward = action.find("students");
    9. 	  System.out.println(forward);
    10. 	}
    11.  
    12. }

    测试结果：

    若我们故意将action中的路径写错

    1. package com.zking.mymvc.framework;
    2.  
    3. public class Test {
    4. public static void main(String[] args) {
    5. 		ConfigModel config=ConfigModelFactory.getConfig();
    6. 	  ActionModel action = config.find("/studentction");
    7. 	  System.out.println(action);
    8. 	  ForwardModel forward = action.find("students");
    9. 	  System.out.println(forward);
    10. 	}
    11.  
    12. }

     效果图如下：就会显示自定义异常该路径找不到

     

  • 相关阅读:
    PHP 二手物品交易网站系统mysql数据库web结构apache计算机软件工程网页wamp
    kubernetes—Service介绍
    六、串口通信
    JVM基础06_StringTable
    【MySQL】学习多表查询和笛卡尔积
    车船边缘网关是如何给车辆船只定位的？
    【Unity】旋转的尽头是使用四元数让物体旋转
    es6（二）——常用es6说明
    谷歌搜索引擎关键词优化，竞价排名怎么做？大舍传媒
    Yolov8魔术师：卷积变体大作战，涨点创新对比实验，提供CVPR2023、ICCV2023等改进方案
  • 原文地址：https://blog.csdn.net/weixin_62270300/article/details/125613799