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javaconnection-poolingc3p0

Detect invalid credentials being passed to c3p0 connection pool

I'm writing a program that does some stuff on the database. Users are allowed to configure db processes, by passing db host port, type and credentials. It all works fine when values are correct. But when user passes invalid credentials I would like to show an error. So here is the part where I create my connection pool

ComboPooledDataSource cpds = new ComboPooledDataSource();
cpds.setJdbcUrl( connectionUrl );
cpds.setUser(username);
cpds.setPassword(password);

And later to verify if all is ok with the connection I do

cpds.getConnection()

I would expect to get some SQLException with vendor specific error saying that credentials are invalid (which happens when you use typical DriverManager way of getting the connection), but instead the process waits until a connection checkout exception is thrown

java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
    at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:77)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:690)
....
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@20014b8 -- timeout at awaitAvailable()
    at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1467)
    at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
    ... 66 more

How can I identify that there is a invalid credential issue with c3p0?

Solution

  • Your best way to validate provided credentials/JDBC params is to avoid connection pool at all.

    Open dedicated connection just for this purpose and try to execute simplest SQL against new connection (eg SELECT 1 or similar). After success, you can pass them to C3P0 otherwise propagate error back to user.