我的JDBC代码有问题。这是相关代码：

/** method for checking password into the Oracle database */

public String CheckUserDB(String userToCheck) throws SQLException {

String storedPassword;

if (ds == null) throw new SQLException("No data source");

Connection conn = ds.getConnection();

if (conn == null) throw new SQLException("No connection");

try {

conn.setAutoCommit(false);

boolean committed = false;

try {

PreparedStatement passwordQuery = conn.prepareStatement(

"SELECT passwd from USERS WHERE userz = ?");

passwordQuery.setString(1, userToCheck);

ResultSet result = passwordQuery.executeQuery();

result.next();

storedPassword = result.getString("passwd");

conn.commit();

committed = true;

} finally {

if (!committed) conn.rollback();

}

}

finally {

conn.close();

}

return storedPassword;

}

这是例外：

java.sql.SQLException: Exhausted Resultset

oracle.jdbc.driver.OracleResultSetImpl.getString(OracleResultSetImpl.java:1270)

oracle.jdbc.driver.OracleResultSet.getString(OracleResultSet.java:494)

org.jboss.jca.adapters.jdbc.WrappedResultSet.getString(WrappedResultSet.java:1359)

com.dx.sr_57.user_check.CheckUserDB(user_check.java:100)

com.dx.sr_57.user_check.user_compare(user_check.java:123)

sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

java.lang.reflect.Method.invoke(Method.java:601)

org.apache.el.parser.AstValue.invoke(AstValue.java:196)

org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)

com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)

javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)

com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)

javax.faces.component.UICommand.broadcast(UICommand.java:315)

javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)

javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)

com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)

com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)

com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)

javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)

这是怎么引起的，我该如何解决？