is resultSet need to be synchronized in a web environment

[outis]

Hi, all, i need to put a web application stable and
i found that all the query follows the same structure:

public synchronized Vector getProfile(Integer profileId) throws SQLException {
try {
conn = con.getConnection();
pstmt = conn.prepareStatement("select...
while (rs.next()) {
// ADD DATA IN A VECTOR
}
} catch (SQLException e) {
finally{
// close resources
}
return vector;
}

I need to know if the reserved word is necessary when i
retrieve data from a DataBase. And if they are one of posibles causes of my application crash down

I will apreciate your comments.

 

[dbleyl]

No. JDBC does not require this, but whoever wrote the code may have used synchronized to work around an idiosyncracy in the driver. The ODBC-JDBC Bridge Driver used in conjunction with MS Access comes to mind.

One observation is that you are adding data to a Vector, which is synchronized, as opposed to ArrayList, which is not.

If this code is scattered through out the app, consider a utility or super class impl that would centralize the jdbc code, that way testing it would be a matter of changing one method.

By the way, what object is con? Or, more to the point, how do manage your connections? You should consider using a DataSource if you aren't doing so now. Post more of the class and db config.

 

[outis]

I use a connection pool as attribute of class

private static oracle.jdbc.pool.OracleConnectionCacheImpl con;
an then I call the following method in the constructor

public static void createConnectionPool() throws SQLException {
try {
con = new OracleConnectionCacheImpl();
con.setDriverType(driverType);
con.setUser(user);
con.setPassword(password);
con.setServerName(serverName);
con.setDatabaseName(databaseName);
con.setNetworkProtocol(networkProtocol);
con.setPortNumber(portNumber);
con.setMinLimit(minLimit);
con.setMaxLimit(maxLimit);
con.setCacheScheme(con.FIXED_WAIT_SCHEME);
System.out.println("ConnectionPoolOracle created...");

} catch (SQLException e) {
e.printStackTrace();
throw new SQLException("Failed connection to database");
}
}
I use this class to manage all the bussines logic.
so I have all the methods declared in this class.

 

[dbleyl]

Do you have an error log or stack trace when the application
crashes?