package cn.curry.action;/*** Created by Curry on 2017/3/15.*/
public class ActionManager {public static Action getActionClass(String className) throws Exception{Class clazz=null;Action action=null;clazz=Thread.currentThread().getContextClassLoader().loadClass(className);if (clazz==null){clazz=Class.forName(className);}if (action==null){action=(Action) clazz.newInstance();}return action;}
}然后我们再定义一个ActionMapping类，这个类定义了几个属性，类似于实体类的作用。

package cn.curry.action;import java.util.HashMap;
import java.util.Map;/*** Created by zl on 2017/3/15.*/
public class ActionMapping {private String name;private String className;private Map<String,String> map=new HashMap<String, String>();public String getName() {return name;}public void setName(String name) {this.name = name;}public String getClassName() {return className;}public void setClassName(String className) {this.className = className;}public String getValue(String key) {return map.get(key);}public void addToMap(String key,String value) {map.put(key,value);}
}然后我们要做解析XML的类，我们的类ActionMappingManager ，我们通过读取用jdom4j读取xml，然后把数据添加到集合中。

package cn.curry.action;import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;/*** Created by zl on 2017/3/15.*/
public class ActionMappingManager {private Map<String,ActionMapping> map=new HashMap<String, ActionMapping>();public  ActionMapping getValue(String key) {return map.get(key);}public void addToMaps(String key,ActionMapping value) {map.put(key,value);}public ActionMappingManager(String [] files)throws Exception{for (String item:files){init(item);}}public void init(String path)throws Exception{InputStream is=this.getClass().getResourceAsStream("/"+path);Document doc=new SAXReader().read(is);Element root=doc.getRootElement();Element actions=(Element)root.elements("actions").iterator().next();for (Iterator<Element> action=actions.elementIterator("action");action.hasNext();){Element actionnext=action.next();ActionMapping am=new ActionMapping();am.setName(actionnext.attributeValue("name"));am.setClassName(actionnext.attributeValue("class"));for (Iterator<Element> result=actionnext.elementIterator("result");result.hasNext();){Element resultnext=result.next();String name=resultnext.attributeValue("name");String value=resultnext.getText();if (name==null||"".equals(name)){name="success";}am.addToMap(name,value);}map.put(am.getName(),am);}}
}接下来我们要定义一个servlet来获取请求，LoginServlet.主要通过获取的请求来找到frame.xml.

package cn.curry.servlet;import cn.curry.action.Action;
import cn.curry.action.ActionManager;
import cn.curry.action.ActionMapping;
import cn.curry.action.ActionMappingManager;
import org.omg.PortableInterceptor.ACTIVE;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;/*** Created by zl on 2017/3/15.*/
public class LoginServlet extends HttpServlet {private ActionMappingManager manager=null;private String getClassName(HttpServletRequest request){String uri=request.getRequestURI();System.out.println(uri+"        uri");String context=request.getContextPath();System.out.println(context+"             context");String result=uri.substring(context.length());System.out.println(result+"              result");return result.substring(1,result.lastIndexOf("."));}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String key=getClassName(request);System.out.println(key+"           key");try {ActionMapping actionMapping=manager.getValue(key);System.out.println(actionMapping.getClassName()+"            classname");Action action= ActionManager.getActionClass(actionMapping.getClassName());String result=action.execute(request,response);System.out.println(result+"                   result");String path=actionMapping.getValue(result);System.out.println(path+"                path");request.getRequestDispatcher(path).forward(request,response);} catch (Exception e) {e.printStackTrace();}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request,response);}@Overridepublic void init(ServletConfig config) throws ServletException {String fileName=config.getInitParameter("config");String file[]=null;if(fileName==null){file=new String[]{"myframe.xml"};}else {fileName.split(",");}try {manager=new ActionMappingManager(file);} catch (Exception e) {e.printStackTrace();}}
}最后我们配置一下web.xml，然后就书写页面：

<!DOCTYPE web-app PUBLIC"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN""http://java.sun.com/dtd/web-app_2_3.dtd" ><web-app><display-name>Archetype Created Web Application</display-name><servlet><servlet-name>LoginServlet</servlet-name><servlet-class>cn.curry.servlet.LoginServlet</servlet-class></servlet><servlet-mapping><servlet-name>LoginServlet</servlet-name><url-pattern>*.action</url-pattern></servlet-mapping><welcome-file-list><welcome-file>login.jsp</welcome-file></welcome-file-list>
</web-app>

书写页面，我们准备了两个页面，一个login.jsp。一个success.jsp。

首先看login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>登录</title>
</head>
<body>
<form action="login.action" method="post"><input name="name"><br><input type="submit" value="登陆"/>
</form>
</body>
</html>然后看success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>登录</title>
</head>
<body>
<h2>登录成功</h2>
</body>
</html>

最后我们看一下运行效果

大家想要更好的理解，需要自己调试看一下每一步怎么走的。

还有就是使用intellij idea遇到各种问题如果，大家有使用idea的相关问题也可以一起讨论。