工厂模式配置servlet(servlet升级版)-526互联

1、创建一个类

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class DeptController extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html");

        PrintWriter out = resp.getWriter();
        out.println("<html><body>");
        out.println("<h1>hello dept</h1>");
        out.println("<body></html>");
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }
}

2、创建一个总的servlet类

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ResourceBundle;

/*所有的servlet都通过这个AllController来转发*/
public class AllController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 如何转发给具体的干活的Controller
        //System.out.println(req.getRequestURL());//结果：http://localhost:8080/mvc01_war_exploded/dept.do
        //System.out.println(req.getRequestURI());//结果：/mvc01_war_exploded/dept.do
        //System.out.println(req.getServletPath());//结果：/dept.do

        //获得请求的url
        String requestUrl = req.getServletPath().substring(1);

        //判断请求地址来进行响应的调用（推荐使用工厂模式）
        if ("dept.do".equals(requestUrl)) {
            DeptController dept = new DeptController();
            dept.doPost(req,resp);
        } 
    }
}

3、配置servlet在web.xml中

点击查看代码

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
<!--原本是一个类配置一个servlet,现在都使用一个用*.do来标识-->
    <servlet>
        <servlet-name>all</servlet-name>
        <servlet-class>com.bh.controller.AllController</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>all</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>



    <!--<servlet>
        <servlet-name>dept</servlet-name>
        <servlet-class>com.bh.controller.DeptController</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>dept</servlet-name>
        <url-pattern>/dept</url-pattern>
    </servlet-mapping>-->

</web-app>

工厂模式版
1、创建一个接口

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public interface IAction {
    public void doAction(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;

}

2、创建实现类

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class DeptController1 implements IAction {
    @Override
    public void doAction(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");

        PrintWriter out = response.getWriter();
        out.println("<html><body>");
        out.println("<h1>hello DEPT</h1>");
        out.println("</body></html>");
    }
}

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class EmpController implements IAction{
    @Override
    public void doAction(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");

        PrintWriter out = response.getWriter();
        out.println("<html><body>");
        out.println("<h1>hello EMP</h1>");
        out.println("</body></html>");
    }
}

3、配置properties文件

点击查看代码

dept.do=com.bh.controller.DeptController1
emp.do=com.bh.controller.EmpController

4、创建总的servlet类

点击查看代码

package com.bh.controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ResourceBundle;

/*所有的servlet都通过这个AllController来转发*/
public class AllController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 如何转发给具体的干活的Controller
        //System.out.println(req.getRequestURL());//结果：http://localhost:8080/mvc01_war_exploded/dept.do
        //System.out.println(req.getRequestURI());//结果：/mvc01_war_exploded/dept.do
        //System.out.println(req.getServletPath());//结果：/dept.do

        //获得请求的url
        String requestUrl = req.getServletPath().substring(1);

        //判断请求地址来进行响应的调用（推荐使用工厂模式）
    /*    if ("dept.do".equals(requestUrl)) {
            DeptController dept = new DeptController();
            dept.doPost(req,resp);
        } else if("emp.do".equals(requestUrl)){
            EmpController emp = new EmpController();
        } else if ("xxx.do") {
            XXXControll xxx = new XXControl();
        }*/
        //工厂模式
        //读取url的配置文件
        ResourceBundle rb = ResourceBundle.getBundle("url");
        String classname = rb.getString(requestUrl);


        IAction action=null;

        //根据干活的类,创建类的实例
        try {
            Class clz = Class.forName(classname);
             action = (IAction) clz.newInstance();
        } catch (ClassNotFoundException e) {

        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
        action.doAction(req,resp);


    }
}

5、配置web.xml文件

点击查看代码

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <servlet>
        <servlet-name>all</servlet-name>
        <servlet-class>com.bh.controller.AllController</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>all</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>

</web-app>