[英]TimerTask not running
我正在構建一個應用程序,該應用程序每分鍾都會查詢一次數據庫。 我使用TimerTask類查詢數據庫。 該方法工作了一段時間,但完全停止了。 我該怎么辦? 這是下面的代碼
public class DateMgr extends TimerTask{
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost:3306/reminder";
static final String USER = "username";
static final String PASS = "password";
@Override
public void run(){
Statement stmt = null;
Connection conn = null;
try{
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm");
//get current date time with Date()
Date d = new Date();
String m = dateFormat.format(d);
String s = m + ":00.0";
System.out.println(dateFormat.format(s));
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to a selected database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
System.out.println("Connected database successfully...");
//STEP 4: Execute a query
System.out.println("Creating statement...");
stmt = conn.createStatement();
String sql = "SELECT * FROM reminder.list";
ResultSet rs = stmt.executeQuery(sql);
//STEP 5: Extract data from result set
while(rs.next()){
//Retrieve by column name
int id = rs.getInt("id");
String message = rs.getString("Message");
String when = rs.getString("When");
System.out.println( "Time for " + message + " At " + when);
}
rs.close();
}catch (Exception e){
}
}
}
這是帶有main()方法的Timer類
public class Reminder {
Timer timer;
public Reminder(int seconds) {
timer = new Timer();
timer.schedule(new DateMgr(), 0, seconds*1000);
}
public static void main (String args[]){
new Reminder(20);
}
}
您:
finally
沒有釋放數據庫資源的位置; 您的程序停止工作,因為每次任務運行時,都會掛起一個數據庫連接。 很快,沒有更多的連接可以獲取,但是您沒有決定這樣做,因為您決定不記錄該異常。
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