需要修改java时间戳以从数据库中获取最新记录
我已经编写了一个webservice,它将负责向用户界面显示数据库中最新插入或更新的记录 这是我的问题需要修改java时间戳以从数据库中获取最新记录,java,mysql,jdbc,timestamp,Java,Mysql,Jdbc,Timestamp,我已经编写了一个webservice,它将负责向用户界面显示数据库中最新插入或更新的记录 这是我的问题 String selectSQL = "SELECT id , VendorName , Item , updated_at , created_at from Orders where updated_at > ? OR created_at > ?"; 这是我的桌子结构 mysql> select * from Orders; +-------+-----------
String selectSQL = "SELECT id , VendorName , Item , updated_at , created_at from Orders where updated_at > ? OR created_at > ?";
这是我的桌子结构
mysql> select * from Orders;
+-------+--------------+----------+---------------------+---------------------+
| id | VendorName | Item | updated_at | created_at |
+-------+--------------+----------+---------------------+---------------------+
| 12345 | PoppyCounter | Chocltae | 2014-05-08 18:49:42 | 2014-05-08 18:49:42 |
+-------+--------------+----------+---------------------+---------------------+
1 row in set (0.00 sec)
我正在使用如下所示的currenttimestamp进行检查
java.sql.Timestamp date = new java.sql.Timestamp(new java.util.Date().getTime());
如何使日期少于1分钟???
package com.serviceees;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import com.google.gson.Gson;
import dto.Orders;
@Path("/updates")
public class DBPollerService {
@GET
@Produces("application/json")
public String getUpdates() {
System.out.println("getUpdates called");
String clientResponse = "Error";
ArrayList<Orders> newOrdersList = new ArrayList<Orders>();
Gson gson = new Gson();
try {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
System.out.println("connection");
Connection connection = null;
PreparedStatement preparedStatement = null;
String selectSQL = "SELECT id , VendorName , Item , updated_at , created_at from Orders where updated_at > ? OR created_at > ?";
try {
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "", "");
while (true) {
System.out.println("Into while true");
try {
java.sql.Timestamp date = new java.sql.Timestamp(new java.util.Date().getTime());
preparedStatement = connection.prepareStatement(selectSQL);
preparedStatement.setTimestamp(1, date);
preparedStatement.setTimestamp(2, date);
ResultSet rs = preparedStatement.executeQuery();
while (rs.next()) {
Orders order = new Orders();
order.setId(rs.getInt(1));
order.setVendorName(rs.getString(2));
order.setItem(rs.getString(3));
newOrdersList.add(order);
}
Thread.sleep(3000);
clientResponse = "jsonCallback(["+gson.toJson(newOrdersList)+"])";
return clientResponse;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
}
clientResponse = gson.toJson(newOrdersList);
System.out.println("clientResponse"+clientResponse);
return clientResponse;
}
}
package.com.servicees;
导入java.sql.Connection;
导入java.sql.DriverManager;
导入java.sql.PreparedStatement;
导入java.sql.ResultSet;
导入java.sql.SQLException;
导入java.util.ArrayList;
导入javax.ws.rs.GET;
导入javax.ws.rs.Path;
导入javax.ws.rs.products;
导入com.google.gson.gson;
进口dto订单;
@路径(“/updates”)
公共类DBPollerService{
@得到
@生成(“应用程序/json”)
公共字符串getUpdates(){
System.out.println(“调用getUpdates”);
字符串clientResponse=“Error”;
ArrayList newOrdersList=新ArrayList();
Gson Gson=新的Gson();
试一试{
试一试{
Class.forName(“com.mysql.jdbc.Driver”);
}catch(classnotfounde异常){
e、 printStackTrace();
}
System.out.println(“连接”);
连接=空;
PreparedStatement PreparedStatement=null;
String selectSQL=“选择id、供应商名称、项目、更新日期、从更新日期>或创建日期>的订单创建日期”;
试一试{
connection=DriverManager.getConnection(“jdbc:mysql://localhost:3306/test", "", "");
while(true){
System.out.println(“为真时输入”);
试一试{
java.sql.Timestamp date=new java.sql.Timestamp(new java.util.date().getTime());
preparedStatement=connection.prepareStatement(选择SQL);
preparedStatement.setTimestamp(1,日期);
preparedStatement.setTimestamp(2,日期);
ResultSet rs=preparedStatement.executeQuery();
while(rs.next()){
订单=新订单();
order.setId(rs.getInt(1));
order.setVendorName(rs.getString(2));
order.setItem(rs.getString(3));
newOrdersList.add(订单);
}
睡眠(3000);
clientResponse=“jsonCallback([“+gson.toJson(newOrdersList)+”)”;
返回clientResponse;
}捕捉(中断异常e){
e、 printStackTrace();
}
}
}捕获(SQLE异常){
System.out.println(“连接失败!检查输出控制台”);
e、 printStackTrace();
}
}捕获(例外e){
e、 printStackTrace();
}
clientResponse=gson.toJson(newOrdersList);
System.out.println(“clientResponse”+clientResponse);
返回clientResponse;
}
}
提前谢谢 如何使日期少于1分钟 只有零下60000毫秒
Timestamp date = new Timestamp(new Date().getTime()-60 * 1000);
返回此日期对象表示的自1970年1月1日00:00:00 GMT以来的毫秒数 如何使日期少于1分钟 只有零下60000毫秒
Timestamp date = new Timestamp(new Date().getTime()-60 * 1000);
返回此日期对象表示的自1970年1月1日00:00:00 GMT以来的毫秒数 必须从表示当前时间的长值中减去60000毫秒
Timestamp date = new Timestamp(new java.util.Date().getTime() - (60 * 1000));
现在,
date
表示一分钟前的时间您必须从表示当前时间的长值中减去60000毫秒
Timestamp date = new Timestamp(new java.util.Date().getTime() - (60 * 1000));
现在,
date
表示一分钟前的时间虽然从技术上讲这不是对您的问题的回答,但是您可以或者修改SQL语句,只返回最新的行。在MSSQL语法中,它如下所示:
SELECT TOP 1 *
FROM Orders
INNER JOIN (
SELECT id, updated_at AS modified from Orders
UNION
SELECT id, created_at from Orders
) AS whatever ON whatever.id = Orders.id
ORDER BY whatever.modified DESC
这将始终返回上次修改(如在中创建或更新)的任何一行,并且不带任何参数。虽然从技术上讲这不是对您的问题的回答,但您可以修改SQL语句,只返回最新的行。在MSSQL语法中,它如下所示:
SELECT TOP 1 *
FROM Orders
INNER JOIN (
SELECT id, updated_at AS modified from Orders
UNION
SELECT id, created_at from Orders
) AS whatever ON whatever.id = Orders.id
ORDER BY whatever.modified DESC
这将始终返回上次修改(如在中创建或更新)的行,并且不带任何参数