Stream Closed Error
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.*;
publicclass DatabaseInfo{
privatestatic DBConnection dbConn;// connection to DB
/** connects to the SQL Server 2005, using the given credntials
*/
publicstaticboolean 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){returnfalse;}
returntrue;
}
/** disconnects from the SQL Server 2005
*/
publicstaticvoid disconnect(){
try{
dbConn.logout();
}
catch (Exception e){}
}
/** prints the list of tables belonging to the user (dbo) from the current
* database
*/
publicstaticvoid 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
*/
publicstaticvoid 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){}
}
publicstaticvoid main(String args[])throws IOException{
connect();
printTablesList();
printTableInfoAndContent();
disconnect();
}
}
package databaseinfo;
import java.io.*;
import java.sql.*;
publicclass DBConnection{
// maximum no. of rows on the user console screen
privatefinalstaticint 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
*/
publicint 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
*/
publicvoid logout()throws SQLException{
conn.close();
System.out.println("\nSQL Server Connection closed.\n");
}
/** executes SQL queries and prints their output to the screen
*/
publicvoid 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!
