目录

用一个xml-config文件实例：

先看config.xml文件

再看 ActionModel

ConfigModel

ActionNotFoundException

ForwardNotFoundException

ConfigModelFactory

ActionDuplicateDefinitionException

ForwardDuplicateDefinitionException

InvalidPathException

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用一个xml-config文件实例：

•  ActionModel
• ConfigModel
• ForwardModel     
• ActionNotFoundException
• ForwardNotFoundException
• ConfigModelFactory
• ActionDuplicateDefinitionException
• ForwardDuplicateDefinitionException
• InvalidPathException

先看config.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE config[<!ELEMENT config (action*)><!ELEMENT action (forward*)><!ELEMENT forward EMPTY><!ATTLIST actionpath CDATA #REQUIREDtype CDATA #REQUIRED><!ATTLIST forwardname CDATA #REQUIREDpath CDATA #REQUIREDredirect (true|false) "false">
]>
<config><action path="/studentAction" type="org.lisen.mvc.action.StudentAction"><forward name="students" path="/students/studentList.jsp" redirect="false"/></action>
</config>

再看 ActionModel

package com.zking.mymvc.framework;import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;/*** ActionModel类：表示一个Action的模型，包含了Action的路径、类型、转发模型、重定向等属性* */
public class ActionModel {private String path; //Action的路径private String type; //Action的类型，例如：request、ajax等private static Pattern pattern = Pattern.compile("^/.+$"); //静态的正则表达式，用于匹配Action的路径private Map<String, ForwardModel> forwardmap = new HashMap<>(); //转发模型的HashMapprivate Boolean redirect; //是否重定向public String getPath() {return path;}public void setPath(String path) {checkPath(path); //校验Action的路径是否符合规范，即必须以/开头this.path = path;}public String getType() {return type;}public void setType(String type) {this.type = type;}// put()方法用于将ForwardModel转发模型添加到HashMap集合中；public void put(ForwardModel forward) {if(!forwardmap.containsKey(forward.getName())) {forwardmap.put(forward.getName(), forward); //添加转发模型}else {throw new ForwardDuplicateDefinitionException("forward name:"+forward.getName()+" 不能重复");//如果转发模型已经存在，则抛出ForwardDuplicateDefinitionException异常}}// find()方法用于查找指定名称的转发模型，如果不存在则抛出ForwardNotFoundException异常public  ForwardModel find(String name) {if(!forwardmap.containsKey(name)) {return forwardmap.get(name);}else {throw new ForwardNotFoundException("forward name:"+name+"不存在");//如果转发模型不存在，则抛出ForwardNotFoundException异常}}// setRedirect()方法用于设置属性redirect的值必须为true或者false；public void setRedirect(String redirect) {if("true".equals(redirect) || "false".equals(redirect)){this.redirect=Boolean.valueOf(redirect);}else {throw new RuntimeException("属性redirect的值必须为true或者false");//如果属性redirect的值不为true或者false，则抛出RuntimeException异常}}// checkPath()方法用于校验路径是否符合规范，即必须以/开头；public void checkPath(String path) {Matcher matcher = pattern.matcher(path); //匹配Action的路径是否符合规范boolean b = matcher.matches();if(!b) {throw new InvalidPathException("ForwardModel.path["+path+"]必须以/开头");//如果Action的路径不符合规范，则抛出InvalidPathException异常}}}

ConfigModel

public class ConfigModel {private Map<String, ActionModel> actionMap = new HashMap<>();//根据指定的路径 path，在 actionMap 中查找对应的 ActionModel 对象并返回。public ActionModel find(String path) {if(actionMap.containsKey(path)) {return actionMap.get(path);}else {throw new RuntimeException("action path:"+path+"没有找到");}}//将指定的 ActionModel 对象存储到 actionMap 中。public void put(ActionModel action) {if(!actionMap.containsKey(action.getPath())) {actionMap.put(action.getPath(), action);}else {//如果该对象的路径已经存在于 actionMap 中，则抛出自定义的 ActionDuplicateDefinitionException 异常，提示路径重复定义。 throw new ActionDuplicateDefinitionException("action path:"+action.getPath()+"重复定义");}}}

ForwardModel     

public class ForwardModel {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(String redirect) {this.redirect = Boolean.valueOf(redirect);}}

ActionNotFoundException

/** action找不到指定路径*/
public class ActionNotFoundException extends RuntimeException{public ActionNotFoundException() {super();}public ActionNotFoundException(String msg) {super(msg);}public ActionNotFoundException(String msg,Throwable cause) {super(msg,cause);}}

ForwardNotFoundException

public class ForwardModel {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(String redirect) {this.redirect = Boolean.valueOf(redirect);}}

ConfigModelFactory

public class ConfigModelFactory {//私有化构造方法，确保该类不会被实例化private ConfigModelFactory() {}//使用饿汉模式，类加载时就初始化了config对象private static ConfigModel config = null;static {//读取配置文件config.xmlInputStream in = ConfigModelFactory.class.getResourceAsStream("/config.xml");SAXReader reader  = new SAXReader();Document doc;try {doc = reader.read(in);Element root = doc.getRootElement();config = new ConfigModel();//读取每个action节点List<Element> actions = root.selectNodes("action");for (Element action : actions) {String actionPath = action.attributeValue("path");String actionType = action.attributeValue("type");//创建ActionModel对象ActionModel actionModel = new ActionModel();actionModel.setPath(actionPath);actionModel.setType(actionType);//读取每个action节点下的forward子节点List<Element> forwards = action.selectNodes("forward");for (Element forward : forwards) {String forwardPath = forward.attributeValue("path");String forwardName = forward.attributeValue("name");String redirect = forward.attributeValue("redirect");//创建ForwardModel对象ForwardModel forwardModel = new ForwardModel();forwardModel.setPath(forwardPath);forwardModel.setName(forwardName);forwardModel.setRedirect(redirect);//将ForwardModel对象放入ActionModel对象中actionModel.put(forwardModel);}//将ActionModel对象放入ConfigModel对象中config.put(actionModel);}} catch (Exception e) {//抛出运行时异常throw new RuntimeException("解析config.xml发生异常", e.getCause());}}//提供一个方法获取config对象public static ConfigModel getConfigModel() {return config;}public static void main(String[] args) throws DocumentException {//测试ActionModel action = config.find("/studentAction");System.out.println(action.getType());System.out.println("yes");}
}

ActionDuplicateDefinitionException

/** action重复定义异常*/
public class ActionDuplicateDefinitionException extends RuntimeException{public ActionDuplicateDefinitionException() {super();}public ActionDuplicateDefinitionException(String msg) {super(msg);}public ActionDuplicateDefinitionException(String msg,Throwable cause) {super(msg,cause);}
}

ForwardDuplicateDefinitionException

/*** forward重复定义异常* @author PC**/
public class ForwardDuplicateDefinitionException extends RuntimeException{public ForwardDuplicateDefinitionException() {super();}public ForwardDuplicateDefinitionException(String msg) {super(msg);}public ForwardDuplicateDefinitionException(String msg,Throwable cause) {super(msg,cause);}

InvalidPathException

public class InvalidPathException extends RuntimeException{public InvalidPathException() {super();}public InvalidPathException(String msg) {super(msg);}public InvalidPathException(String msg,Throwable cause) {super(msg,cause);}