Stream Closed Error

Question

Hello!
I have this 2-class package which gets informations on Microsoft SQL Server 2005 tables and table content. It worked perfectly on J2SE 5. Today I moved to Java J2SE1.6 u1 and recompiled the project. Now, it triggers bizzare Steam Closed exceptions when trying to read a line from the keyboard (if I let exceptions to be thrown). I found several posts regarding this readLine-stream closed issue on the java forums, but none answered this problem satisfactorily. This is my code:
package databaseinfo;
import java.io.*;
import java.sql.*;
public class DatabaseInfo {
   private static DBConnection dbConn; // connection to DB
   /** connects to the SQL Server 2005, using the given credntials
   public static boolean connect() {
       String username = "test";
       String password = "test";
       String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; // JDBC driver for connecting to MSSQL 2005
       String url = "jdbc:sqlserver://FIREBLADE\\SQLEXPRESS"; // JDBC connection URL to MSSQL 2005
       try {
           dbConn = new DBConnection(username,password,driver,url);
       catch (Exception e) { return false; }
       return true;
   /** disconnects from the SQL Server 2005
   public static void disconnect() {
       try {
           dbConn.logout();
       catch (Exception e) { }
   /** prints the list of tables belonging to the user (dbo) from the current
    *  database
   public static void printTablesList() {
       try {
            dbConn.printQueryResult("EXEC sp_tables @table_owner=dbo");
       catch (Exception e) { return; }
   /** prints extra information and the content of a user-given table
   public static void printTableInfoAndContent() throws IOException {
       try {
           BufferedReader in = new BufferedReader(
                               new InputStreamReader(System.in));
           String tableName;
           System.out.println("\nGet extra information and the content of which table? ");
           tableName = in.readLine();
           in.close();
           dbConn.printQueryResult("EXEC sp_columns @table_name=" + tableName);
           System.out.println();
           dbConn.printQueryResult("SELECT * FROM " + tableName);       
       catch (IOException e) { }
   public static void main(String args[]) throws IOException {
       connect();
       printTablesList();
       printTableInfoAndContent();
       disconnect();
package databaseinfo;
import java.io.*;
import java.sql.*;
public class DBConnection {
    // maximum no. of rows on the user console screen
    private final static int maxRowCount = 25;
    private Connection conn; // connection to DB
    /** connects to the MSSQL 2005 database
    public DBConnection (String username, String password, String driver,
                         String url) throws ClassNotFoundException, SQLException {
         login(username,password,driver,url);
    /** login to SQL Server 2005 for a user having a username and a passsword,
     *  using a certain database driver and a given url
    public int login(String username, String password, String driver, String url)
                                                  throws ClassNotFoundException,
                                                         SQLException {
        Class.forName(driver); // sets the JDBC driver
        conn = DriverManager.getConnection(url,username,password); // obtains the JDBC connection
        if (conn != null)
            System.out.println("\nSQL Server Connection established ...\n");
        else {
            System.out.println("\nBad username and/or password.\n");
            return 0;
        return 1;     
    /** closes the JDBC connection
    public void logout() throws SQLException {   
        conn.close();
        System.out.println("\nSQL Server Connection closed.\n");
    /** executes SQL queries and prints their output to the screen
    public void printQueryResult(String sql) {
        try {
                BufferedReader in = new BufferedReader(
                                    new InputStreamReader(System.in));
                int rowCount = 0;
                Statement st = conn.createStatement();
          ResultSet rs = st.executeQuery(sql);
          ResultSetMetaData rsmd = rs.getMetaData();
          int numberOfColumns = rsmd.getColumnCount();   
          int i;
                for (i = 1; i <= numberOfColumns; i++)
                    System.out.print(rsmd.getColumnName(i)+"\t");
                System.out.println();
          while (rs.next()) {
                        if ((rowCount != 0) && (rowCount % maxRowCount == 0)) {
                                System.out.println("\nPress ENTER to continue ... ");
                                in.read();
                        for (i = 1; i <= numberOfColumns; i++)     
                   System.out.print(rs.getString(i) + "\t\t");
                        rowCount++;
                        System.out.println();
                in.close();
         catch (Exception e) { }
}Thanks for reading this post!

Answer 1

Don't close the input stream, and don't create a new one every time you want to read - create one for the life of the program.