备注：类实现ServletContextListener,在web.xml配置，之后服务启动该定时器类自动加载

package com.leadlt.common.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class TestTimer implements ServletContextListener{
public static void doCon() throws Exception, Exception, Exception {
Connection con = null;
Statement st = null;
ResultSet rs = null;
// 获得Oracle驱动的实例
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
// 获得连接对象(提供：地址，用户名，密码)
con = DriverManager.getConnection(
"jdbc:oracle:thin:@192.168.1.121:1521:orcl", "parking",
"parking");

if (!con.isClosed())
System.out.println("Successfully connected ");
else
System.out.println("failed connected");

// 建立一个Statement，数据库对象
st = con.createStatement();
// 运行SQL查询语句
//rs = st.executeQuery("select * from DAY_TRAFFIC");
//rs=st.executeQuery("insert into DAY_TRAFFIC (parkno,time1,time2,ID,types,day_time) VALUES (parkno,0,0,DAY_TRAFFIC_SEQ.nextval,'year',sysdate)");
rs=st.executeQuery("insert into DAY_TRAFFIC (parkno,ID) VALUES ('0',7)");
System.out.println(rs);
// 读取结果集
while (rs.next()) {
System.out.println("parkno:" + rs.getString(1));
/*
* System.out.println("time1:" + rs.getInt(2));
* System.out.println("time2:" + rs.getInt(3));
* System.out.println("time3:" + rs.getInt(4));
* System.out.println("time4:" + rs.getInt(5));
* System.out.println("time5:" + rs.getInt(6));
* System.out.println("time6:" + rs.getInt(7));
* System.out.println("time7:" + rs.getInt(8));
* System.out.println("time8:" + rs.getInt(9));
* System.out.println("time9:" + rs.getInt(10));
* System.out.println("time10:" + rs.getInt(11));
* System.out.println("time11:" + rs.getInt(12));
* System.out.println("time12:" + rs.getInt(13));
* System.out.println("day_time:" + rs.getDate(26));
* System.out.println("ID:" + rs.getInt(27));
* System.out.println("types:" + rs.getString(28));
*/
}
// 关闭链接
con.close();
// run();
}

static int count = 0;
public static void showTimer() {
TimerTask task = new TimerTask() {
@Override
public void run() {
++count;
System.out.println("时间=" + new Date() + " 执行了" + count + "次"); // 1次
try {
doCon();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};

// 设置执行时间
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DAY_OF_MONTH);// 每天
// 定制每天的12:15:15执行，
calendar.set(year, month, day, 12, 15, 15);
Date date = calendar.getTime();
Timer timer = new Timer();
System.out.println(date);

int period = 2 * 1000;
// 每天的date时刻执行task，每隔2秒重复执行
timer.schedule(task, date, period);
// 每天的date时刻执行task, 仅执行一次
// timer.schedule(task, date);
}

/*public static void main(String[] args) {
showTimer();
}*/

public void contextDestroyed(ServletContextEvent arg0) {
// TODO Auto-generated method stub

}

public void contextInitialized(ServletContextEvent arg0) {
// TODO Auto-generated method stub
showTimer();

}
}