java注册用户代码_java牛每日注册用户数

package com.javaniu;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.HashMap;

import java.util.Map;

public class java牛每日注册用户数 {

public static SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

public static Map stat() {

Map map = new HashMap();

Connection conn = null;

try {

String userName = "root";

String password = "111111";

String jdbcurl = "jdbc:mysql://localhost:3306/javaniu2?useUnicode=true&characterEncoding=utf-8";

Class.forName("com.mysql.jdbc.Driver").newInstance();

conn = DriverManager.getConnection(jdbcurl, userName, password);

String sql = "select create_time from user where status=2";

PreparedStatement pstmt = conn.prepareStatement(sql);

ResultSet rs = pstmt.executeQuery();

while (rs.next()) {

Date _createTime = rs.getDate("create_time");

String createTime = format.format(_createTime);

Integer count = map.get(createTime);

if (count == null) {

count = 0;

}

count++;

map.put(createTime, count);

System.out.println(createTime+"="+count);

}

pstmt.close();

} catch (Exception e) {

System.err.println("Cannot connect to database server,Exception:"

+ e.getMessage());

} finally {

if (conn != null) {

try {

conn.close();

conn = null;

} catch (Exception e) {

}

}

}

return map;

}

public static void write(String path, String content, String encoding)

throws IOException {

File file = new File(path);

file.delete();

file.createNewFile();

BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(

new FileOutputStream(file), encoding));

writer.write(content);

writer.close();

}

public static void main(String[] args) throws IOException {

File file = new File("stat.txt");

file.delete();

file.createNewFile();

BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(

new FileOutputStream(file), "utf-8"));

Map map = stat();

for (String date : map.keySet()) {

Integer count = map.get(date);

writer.write(date + "," + count + "\n");

}

writer.close();

}

}