教大家使用java实现顶一下踩一下功能

本文实例为大家分享了java实现顶一下踩一下功能的具体代码,供大家参考,具体内容如下

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效果图如下:

教大家使用java实现顶一下踩一下功能

主页面index.html:

 
 
 
 
Digg 
 
 
 
 
 
 
 
 

后台servlet:

package com.test; 
 
import java.io.IOException; 
import java.io.PrintWriter; 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 
import java.text.NumberFormat; 
 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
public class Digg extends HttpServlet { 
  private static Connection con = null; 
  private static Statement stmt = null; 
 
  /** 
   * Constructor of the object. 
   */ 
  public Digg() { 
    super(); 
  } 
 
  /** 
   * Destruction of the servlet. 
*/ 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 { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf8"); response.setCharacterEncoding("utf8"); String action = request.getParameter("action"); String digtype = request.getParameter("digtype"); if(action.equals("digs")){ try { response.getWriter().write(dig(digtype)); } catch (Exception e) { e.printStackTrace(); } }else if(action.equals("getdigshtml")){ try { response.getWriter().write(getDigHtml()); } catch (Exception e) { e.printStackTrace(); } } } private String dig(String digtype)throws Exception{ String sql =""; if(digtype.equals("digs")){ sql ="update dig set digs=digs+1 where id =1"; }else{ sql ="update dig set undigs=undigs+1 where id =1"; } int num =stmt.executeUpdate(sql); if(num>0){ return "3"; } return "1"; } public static void main(String[] args){ NumberFormat nf = NumberFormat.getPercentInstance(); nf.setMaximumIntegerDigits(4); nf.setMaximumFractionDigits(6); double d = (double)1/(double)7; System.out.println(nf.format(d)); } private String getDigHtml()throws Exception{ NumberFormat nf = NumberFormat.getPercentInstance(); nf.setMaximumIntegerDigits(3); nf.setMaximumFractionDigits(2); String sql ="select * from dig where id=1"; ResultSet res = stmt.executeQuery(sql); double digSum = 0 ; double unDigSum =0 ; double digSumAll = 0; String digPer = "0%"; String unDigPer = "0%"; while(res.next()){ digSum = res.getInt("digs"); unDigSum = res.getInt("undigs"); } digSumAll = digSum + unDigSum; if(digSumAll !=0 ){ digPer = nf.format(digSum/digSumAll); unDigPer = nf.format(unDigSum/digSumAll); } String str=""; return str; } /** * Initialization of the servlet.
* * @throws ServletException * if an error occurs */ public void init() throws ServletException { try { Class.forName("com.MySQL.jdbc.Driver"); con = DriverManager.getConnection( "jdbc:mysql://172.16.42.39:3306/dig", "root", "12345678"); stmt = con.createStatement(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void closeCon() { try { stmt.close(); con.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

sql语句:

CREATE TABLE dig( 
 id INT PRIMARY KEY, 
 digs INT, 
 undigs INT 
); 
INSERT INTO dig VALUES(1,0,0); 

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持创新互联。


新闻标题:教大家使用java实现顶一下踩一下功能
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