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connection cannot be cast to oracle jdbc oracleconnection

connection cannot be cast to oracle jdbc oracleconnection  using -'java,oracle,hibernate,jdbc,jndi'

Why java.sql.Connection cannot be cast to oracle.jdbc.OracleConnection in code below?

My main goal is to pass to Oracle connection new user name and save it in 'SESSION' table in for example 'osuser' column because I want to trace in DB user changes and display it in the table.

public class AuditLogDAOImpl implements AuditLogDAO {

    EntityManager em;

    @Resource(name = "dataSource")
    DataSource dataSource;

    public void init() {

        try {
            Connection connection = DataSourceUtils.getConnection(dataSource);
            OracleConnection oracleConnection = (OracleConnection) connection; //Here I got cast exception!

            String metrics[] = new String[OracleConnection.END_TO_END_STATE_INDEX_MAX];
            metrics[OracleConnection.END_TO_END_CLIENTID_INDEX] = "my_new_username";

            oracleConnection.setEndToEndMetrics(metrics, (short) 0);

            java.util.Properties props = new java.util.Properties();
            props.put("osuser", "newValue");


        } catch (SQLException e) {

Here is error log:

10:42:29,251 INFO  [STDOUT] org.jboss.resource.adapter.jdbc.jdk6.WrappedConnectionJDK6@bcc8cb
10:42:51,701 ERROR [STDERR] java.lang.ClassCastException: $Proxy286 cannot be cast to oracle.jdbc.OracleConnection

Generally I have 2 problem in this case:

why cast from Connection to OracleConnection fails and
what is the best way to implement my intend (I mean set the new user name to v$session.osuser in Oracle DB?

I work with Oracle 11g, Hibernate (using entity manager), data source via jndi.

Please help, thanks!


After some improvement the problem with casting still exists.


Connection connection = DataSourceUtils.getConnection(dataSource);
connection = ((org.jboss.resource.adapter.jdbc.WrappedConnection)connection).getUnderlyingConnection();
OracleConnection oracleConnection = (OracleConnection) connection;


java.lang.ClassCastException: $Proxy287 cannot be cast to org.jboss.resource.adapter.jdbc.WrappedConnection


asked Sep 29, 2015 by sujata naik
0 votes

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6 Answers

0 votes

The connection you are retrieving is probably a wrapped connection.

If you really need to get the underlying Oracle connection you should use:

if (connection.isWrapperFor(OracleConnection.class)){
   OracleConnection oracleConnection= connection.unwrap(OracleConnection.class);  
   // recover, not an oracle connection

The isWrapperFor and unwrap methods are available since Java 1.6, and should be meaningfully implemented by the A/S connection wrappers.

answered Sep 29, 2015 by okesh.badhiye
0 votes

The connection pool usually has a wrapper around the real connection instance, that's why your cast fails.

What you are doing wouldn't work anyway, because the parameters in the properties instance are only checked when the connection is established. As you have a connection that is already active, it won't change anything.

You need tou use DBMS_APPLICATION_INFO.SET_CLIENT_INFO() in order to change this for an existing connection.

answered Sep 29, 2015 by sameer rathore
0 votes

This is just for people who come here via search on how to set metrics in OracleConnection, I spend great deal of time on this, so might help someone.

After you get your "connection" this should work:

DatabaseMetaData dmd = connection.getMetaData();
Connection metaDataConnection = null;

if(dmd != null)
    metaDataConnection = dmd.getConnection();

if(!(metaDataConnection instanceof OracleConnection))
    log.error("Connection is not instance of OracleConnection, returning");
    return; /* Not connection u want */

OracleConnection oraConnection = (OracleConnection)metaDataConnection;

String[] metrics = new String[END_TO_END_STATE_INDEX_MAX]; // Do the rest below...

It works for me for OracleConnection, but I face diff issue when setting metrics:

short zero = 0;
oraConnection.setEndToEndMetrics(metrics, zero);

After proxying connection via my method where I set metrics few times, I get:

java.sql.SQLRecoverableException: No more data to read from socket

But I think it has to do with some Spring wiring inits or connection pool.

answered Sep 29, 2015 by patelnikul321
0 votes

i had faced this issue when using spring to get connections. Typically , each layer adds a wrapper over the basic classes. i had just done connection.getClass().getName() to see the runtime type of the connection being retuned. It will be a Wrapper/proxy over which you can easily find the method to get the base OracleConnection type.

answered Sep 29, 2015 by santosh soni
0 votes

You can access the inner OracleObject inside a Wrapper, in this case the wrapper type is NewProxyConnection:

( I've used it in my project, it Worked mistery, just use reflection)

Field[] fieldsConn= connection.getClass().getDeclaredFields();

Object innerConnObject = getFieldByName(fieldsConn,"inner").get(connection);

if(innerConnObject instanceof OracleConnection ){
  OracleConnection oracleConn = (OracleConnection)innerConnObject;
 //OracleConnection unwrap = ((OracleConnection)innerConnObject).unwrap();
  // now you have the OracleObject that the Wrapper 

//Method: Set properties of the ooject accessible.
 public static  Field getFieldByName(Field[] campos, String name) {
    Field f = null;
    for (Field campo : campos) {
        if (campo.getName().equals(name)) {
            f = campo;
    return f;
answered Sep 29, 2015 by sachin wagh
0 votes

Try the following

I had encountered the same issue. We were using spring and it has a class called NativeJdbcExtractor. It has many implementations and the following one works for TomCat. There is a specific implementation for Jboss called the JBossNativeJdbcExtractor

In your DAO you can inject the bean and use the following method

protected NativeJdbcExtractor jdbcExtractor;
Connection conn=jdbcExtractor.getNativeConnection(oracleConnection);
answered Sep 29, 2015 by param.oncemore