Java_Web _Servlet生命周期实验

 

 

 

  1.       第一次加载这个servlet程序时（选择右边的servlet程序，注意servlet程序没有main函数，因此执行的是run as servlet Application ）,同时执行init()方法
  2.       然后开始输入servlet网址，注意不用加java或者php，加了反而运行不了，这是会先执行service()方法，在执行doget()方法；
  3.       然后点击计算，开始得到个人所得税部分，这个时候显示执行service()方法，在执行dopost()方法；
  4.       最后，关闭tomcat，执行destory()方法；

      init()方法和destory()方法只会执行一次，而service每次都会执行

 

 

 

 

 

个人所得税代码

     

package com.helloweenvsfei.servlet;

import java.io.IOException;
import java.io.PrintWriter;

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

public class LifeCycleServlet extends HttpServlet {

    private static final long serialVersionUID = -7197419401412129310L;
    
    private static double startPoint = 0;

    @Override
    public void init() throws ServletException {
        this.log("执行 init() 方法 ... ");
        ServletConfig conf = this.getServletConfig();
        startPoint = Double.parseDouble(conf.getInitParameter("startPoint"));
    }
    

    @Override
    protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {
        this.log("执行 service() 方法 ... ");
        super.service(arg0, arg1);
    }

    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        this.log("执行 doPost() 方法 ... ");
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<HTML><HEAD><TITLE>个人所得税计算</TITLE></HEAD>");
        out.println("<link rel='stylesheet' type='text/css' href='../css/style.css'>");
        out.println("<BODY>");
        
        out.println("<div align='center'><br/><fieldset style=width:90%><legend>个税计算器</legend><br/>");
        
        try{
            // 从参数中获取的工资数目
            double income = new Double(request.getParameter("income"));
            // 应纳税部分
            double charge = income - startPoint;
            // 缴税
            double tax = 0;

            if (charge<=0) {tax=0;}
            if (charge>0&&charge<=500) {tax=charge*0.05;}
            if (charge>500&&charge<=2000) {tax=charge*0.1-25;}
            if (charge>2000&&charge<=5000) {tax=charge*0.15-125;}
            if (charge>5000&&charge<=20000) {tax=charge*0.2-375;}
            if (charge>20000&&charge<=40000) {tax=charge*0.25-1375;}
            if (charge>40000&&charge<=60000) {tax=charge*0.30-3375;}
            if (charge>60000&&charge<=80000) {tax=charge*0.35-6375;}
            if (charge>80000&&charge<=100000) {tax=charge*0.4-10375;}
            if (charge>100000) {tax=charge*0.45-15375;}

            out.println("<div style='line'>");
            out.println("    <div class='leftDiv'>您的工资为</div><div class='rightDiv'>" + income + " 元</div>");
            out.println("</div>");
            
            out.println("<div style='line'>");
            out.println("    <div class='leftDiv'>您应纳税</div><div class='rightDiv'>" + tax + " 元</div>");
            out.println("</div><br/>");

            out.println("<input type='button' onclick='history.go(-1);' value='纳税光荣 逃税可耻 返回'  class=button>");
            
        }catch(Exception e){
            out.println("请输入数值类型数据。<input type='button' onclick='history.go(-1);' value='返回'  class=button>");
        }
        out.println("</BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.log("执行 doGet() 方法 ... ");
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
        out.println("<link rel='stylesheet' type='text/css' href='../css/style.css'>");
        out.println("<HTML><HEAD><TITLE>个人所得税计算</TITLE></HEAD>");

        out.println("<div align='center'><br/><fieldset style=width:90%><legend>个税计算器</legend><br/>");
        out.println("<form method='post' action='LifeCycleServlet'>");
        
        out.println("<div style='line'>");
        out.println("    <div class='leftDiv'>您的工资为</div><div align='left' class='rightDiv'><input type='text' name='income'> 单位：元</div>");
        out.println("</div><br/>");
        
        out.println("<div style='line'>");
        out.println("    <div class='leftDiv'></div><div align='left' class='rightDiv'><input type='submit' value='  计算个税  ' class=button></div>");
        out.println("</div>");
        
        out.println("</form>");
        
        out.println("<BODY>");
        out.println("</BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    @Override
    public void destroy() {
        this.log("执行 destroy() 方法 ... ");
        startPoint = 0;
    }
    
}
View Code

 

posted @ 2015-07-18 19:38  好想雨的云  阅读(249)  评论(0)  编辑  收藏  举报