Archive for December, 2008

Remote Desktop Idle Timeout

December 22nd, 2008 13 Comments

Idle Timer has expired

When connecting from Windows Vista or Windows XP Home to a Windows XP Professional SP3 machine via Remote Desktop, I was constantly bothered by timeout issues. I would get the following error message:

Session has been idle over its time limit.
It will be disconnected in 2 minutes.
Press any key now to continue session.

In addition to the error message, the computer running Windows XP Professional SP3 would periodically beep. However, the solution to this is to change the session timeout on the computer you are Remote Desktop to. Follow the step by step instructions below:

  1. Go to the Start Menu and click Run (or press the shortcut combination Windows+R).
  2. In the prompt, type gpedit.msc and click OK.
  3. In the left panel, navigate the hierarchical menu: Computer Configuration > Administrative Templates > Windows Components > Terminal Services > Sessions
  4. Double click the “Sets a time limit for active but idle Terminal Services sessions” property to open up the properties window.
  5. In the popup window, make sure the Enabled selection is chosen and the Idle Session Limit dropdown list is set to Never.
  6. Click Ok and close all windows and applications
  7. Reset the computer for the changes to take effect.

Since making this change, I can remote login to my desktop and leave the session idle overnight without having to worry about the Window machine beeping throughout the night.

Posted in Windows XP Tags: , , , ,

Using PreparedStatement in Java

December 16th, 2008 No Comments

PreparedStatements are used in Java to set up SQL statements. They can be used to insert a set of data to the database or retrieve a set of data from the database.  You can visit the Java API here:  http://java.sun.com/j2se/1.4.2/docs/api/java/sql/PreparedStatement.html

This is how I’ve used the prepared statement to insert data to the database:

First, import the necessary package:

import java.sql.*;

Create the PreparedStatement object:

PreparedStatement pstmt = null;

Create a  String for your SQL statement. For example:

String insert = "INSERT INTO MYTABLE (COL1, COL2, COL3) VALUES (?, ?, ?)";

The question marks represent values being passed into the statement.

Create a Connection to the database. Usually the URL, username and password are stored in a config file but for simplicity, the following can be done:

Connection con = DriverManager.getConnection("<URL>", "<username>", "<password>");

The URL is something like “jdbc:odbc:<db>”. Username is the schema name, and password is the password.

Then, in a try/catch block,

try (
  pstmt = con.prepareStatement(insert);
  pstmt.setString(1, valCol1);  //valCol1 is the String value being inserted for COL1 in the table MYTABLE
  pstmt.setString(2, valCo2);
  pstmt.setString(3, valCo3);
  pstmt.executeQuery();  //executeQuery() is the method used to run the SQL statement
  con.commit();  //commit() will commit the data into MYTABLE
} catch (SQLException e){
  error("Error inserting into db " + e.getMessage());
}

To retrieve data from the db is similar:

This time, you will need to create a ResultSet object to store the retrieved data:

ResultSet rs = null;

This is an example:

public String[] getData(Connection con, String col3) {
  String select = "SELECT COL1, COL2 FROM MYTABLE WHERE COL3 = ?";
  PreparedStatement ps = null;
  ResultSet rs = null;
  List<String> dataArray = new ArrayList<String>(); //This will contain the data from the db
  try{
    ps = con.prepareStatement(select);
    ps.setString(1,  col3); // col3 is the value being set in the SQL statement
    rs = ps.executeQuery(); //this will execute the query and store the result in rs
    while(rs.next()) {
      dataArray.add(rs.getString(1));
    }
  } catch(SQLException e) {
    error("Unable to get data " , e);
  }
  ps.close()  //close the prepared statement
  con.close()  //close the connection
}
Posted in Java, Sql Tags: , ,