使用servlet进行web开发

下面只说业务逻辑层

首先要有一个类继承自HttpServlet类 并重写里面的方法

package com.zhy.t502.entity;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.zhy.t502.biz.Newsbiz;
import com.zhy.t502.biz.Topicbiz;
import com.zhy.t502.biz.impl.Newsbizimpl;
import com.zhy.t502.biz.impl.Topicbizimpl;

public class Fenye extends HttpServlet {
    private Newsbiz nb = new Newsbizimpl();
    private Topicbiz top = new Topicbizimpl();
    /**
     * Constructor of the object.
     */
    public Fenye() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //根据主题查看新闻

        // 取集合
        // 国际新闻
        List gj =nb.findnew(1, 5, 2);
        // 国内新闻
        List gn =nb.findnew(1, 5, 1);
        // 标题集合
        List bt =top.findtop();
        // 新闻集合
        String pn=request.getParameter("pn");

        System.out.println(pn);
        List xw = nb.findnew(Integer.parseInt(pn), 5);

        // 存集合
        request.setAttribute("xw", xw);
        request.setAttribute("bt", bt);
        request.setAttribute("gn", gn);
        request.setAttribute("gj", gj);

        // 跳转
        request.getRequestDispatcher("index.jsp").forward(request, response);  

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            this.doGet(request, response);

    }

    public void init() throws ServletException {
        // Put your code here
    }

}

说明： 这个类是出来由jsp页面发送过来的请求的。一个类只能出来一个请求

然后再web.xml中进行配置

    <servlet>
        <servlet-name>ADDnews</servlet-name>        <!-- 名字 -->
        <servlet-class>com.zhy.t502.entity.Addnews</servlet-class>    <!-- 路径 -->
    </servlet>
    <servlet-mapping>
        <servlet-name>ADDnews</servlet-name>        <!-- 名字 -->
        <url-pattern>/ADDnews</url-pattern>            <!-- jsp页面的请求路径 -->
    </servlet-mapping>

在服务器启动时会最先读取web.xml配置文件