Closed connection error when connection isn't being closed

Question

Hi,
Currently I am trying to connect to an Oracle 11g database via JDBC. However, everytime I run the code I get the following error:
java.sql.SQLException: Closed Connection
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:110)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:171)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:227)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:439)
at oracle.jdbc.driver.T2CConnection.checkError(T2CConnection.java:653)
at oracle.jdbc.driver.T2CConnection.logon(T2CConnection.java:338)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:490)
at oracle.jdbc.driver.T2CConnection.<init>(T2CConnection.java:133)
at oracle.jdbc.driver.T2CDriverExtension.getConnection(T2CDriverExtension.java:53)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:474)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
The error comes from running the below code.
public static Connection connect(String url, String username, String password) {
Connection conn = null;
//String url = "";
// Load the driver
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException cnfe) {
System.err.println("Oracle driver class cannot be found");
cnfe.printStackTrace();
System.exit(1);
// Get the connection
try{
conn = DriverManager.getConnection(url, username, password); *// This is the offending line*
} catch (SQLException sqle) {
System.err.println("Problem connecting, possibly incorrect " +
"username/password or problem communicating with the database");
sqle.printStackTrace();
System.exit(1);
}java.sql.SQLException: Closed Connection
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:110)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:171)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:227)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:439)
at oracle.jdbc.driver.T2CConnection.checkError(T2CConnection.java:653)
at oracle.jdbc.driver.T2CConnection.logon(T2CConnection.java:338)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:490)
at oracle.jdbc.driver.T2CConnection.<init>(T2CConnection.java:133)
at oracle.jdbc.driver.T2CDriverExtension.getConnection(T2CDriverExtension.java:53)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:474)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
// Turn auto commit off
try{
conn.setAutoCommit(false);
} catch (SQLException sqle) {
System.err.println("java.sql.SQLException: Closed Connection // This is the offending line
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:110)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:171)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:227)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:439)
at oracle.jdbc.driver.T2CConnection.checkError(T2CConnection.java:653)
at oracle.jdbc.driver.T2CConnection.logon(T2CConnection.java:338)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:490)
at oracle.jdbc.driver.T2CConnection.<init>(T2CConnection.java:133)
at oracle.jdbc.driver.T2CDriverExtension.getConnection(T2CDriverExtension.java:53)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:474)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)Problem turning off auto commit");
sqle.printStackTrace();
System.exit(1);
return conn;
but the connection is never closed, this is the first time connect is called so it is never opened either.
// This is the offending line
The URL I am using to connect is:
jdbc:oracle:oci8:@mydatabase:1158
The database is stored on a server. I have previously tested the code on a machine with the database stored locally and had no problems. However, ran into this problem now when the database is external. Incase this information helps the software is being run under Linux via Netbeans. The previous testing was performed using Netbeans under Windows.
Any help would be much appreciated.
Thanks,
Martin

Answer 1

Hi i am using the following code and i am getting the same error ....
public class DBConnection {
     private static Connection con=null;
     public DBConnection() {
               System.out.println("In db Connection..");
     public static Connection getConnectionObj(){
          if(con==null){
               con= new DBConnection().getConnection();
               System.out.println("In db Connection.. if");
               return con;
          else{
               System.out.println("In db Connection..else");
               return con;
     private Connection getConnection(){
          Properties prop=new Properties();
          FileWriter fw=null;
          FileInputStream fis=null;
          try{
                       File file=new File("Connection.properties");
               fis=new FileInputStream(file);
               prop.load(fis);
               System.out.println(prop.getProperty("DriverName"));
               System.out.println(prop.getProperty("URL"));
               Class.forName(prop.getProperty("DriverName"));
               System.out.println(prop.getProperty("DriverName"));
               System.out.println(prop.getProperty("URL"));
               con=DriverManager.getConnection(prop.getProperty("URL"),prop.getProperty("UserName"),prop.getProperty("Password"));
               fis.close();
          }catch(Exception e){
               e.printStackTrace();
               if(fw!=null){
                    try {
                         fw.close();
                    } catch (IOException e1) {
                         // TODO Auto-generated catch block
                         e1.printStackTrace();
               if(fis!=null){
                    try {
                         fis.close();
                    } catch (IOException e1) {
                         // TODO Auto-generated catch block
                         e1.printStackTrace();
          return con;
}I am not using the connection pool.
For the first request it is working fine but later request's it is giving the closed connection error.
Thanks in advance.
Edited by: EJP on 10/10/2011 20:28: added {noformat}{noformat} tags: please use them