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：
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。
