Question

如何在java中获取当前日期详细信息？我开发了一个课程：

 public class RetailerWs {

 public String customerData(){
  String customerInfo = "";
  try{
  Class.forName("com.mysql.jdbc.Driver");
  Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/pro","root","");
   //Find customer information where the customer ID is maximum
   PreparedStatement statement =  con.prepareStatement("select * from orders where status='Q' AND date='2012-08-01'");
   ResultSet result = statement.executeQuery();
   int count=0;
    count++;
  // System.out.println(count);
   while(result.next()){
  System.out.println(count);
  }
      }
 catch(Exception exc){
 System.out.println(exc.getMessage());
  }

 return customerInfo;
 }

}

这是另一个班级。

  public class Demo {
  public static void main(String[] args){
    RetailerWs obj = new RetailerWs();
    System.out.println(obj.customerData());
  }

 }

如果我运行demo，则会调用RetailerWs，然后显示count的值。问题是目前我手动插入日期，即

   PreparedStatement statement =  con.prepareStatement("select * from orders where status='Q' AND date='2012-08-01'");

但我想要一个获取当前日期的查询。我该如何创建和调用它？请帮我。

Answer 1

你可以尝试

select * from orders where status='Q' AND date = CURDATE();

Answer 2

您可以使用calendar实现它：

public static Date getToday(Date date) {
    Calendar c = Calendar.getInstance();
    c.setTime(date);
    c.set(Calendar.HOUR_OF_DAY, 0);
    c.set(Calendar.MINUTE, 0);
    c.set(Calendar.SECOND, 0);
    c.set(Calendar.MILLISECOND, 0);
    return c.getTime();
}

Answer 3

用问号替换预备语句中的日期，并使用setDate()方法设置其值：

statement = con.prepareStatement("select * from orders where status='Q' AND date=?");
statement.setDate(1, new Date());

setDate()的第一个参数是?的索引（从1开始）。将此机制用于其他参数（Q）也是一种好习惯。

Answer 4

如果日期列包含时间部分，则需要修改如下所示的查询

select * from orders where status='Q' AND 
date >= CURDATE() and date<CURDATE() +interval 1 day ;

在java中获取当前日期

4 个答案: