使用Intellij Idea自定义MVC框架

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);
    }

    @Override
    public 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。