How to fetch list of tables in database using HibernateDaoSupport?

Question

Here I have added my code. Issue occurs in try block while I am trying fetch list of tables.

Database is MySql
Exception is : java.lang.IllegalArgumentException: node to traverse cannot be null!

public class DBOptimizationDAO extends HibernateDaoSupport {

private static final Log log  = LogFactory.getLog(DBOptimizationDAO.class);

public void optimizeAdapter(String year)
{
    List<com.ecw.adapterservice.beans.TransactionInbound> transactionInboundList = null;
    StringBuilder queries = new StringBuilder();
    try {       
        transactionInboundList = (List<com.ecw.adapterservice.beans.TransactionInbound>)super.getHibernateTemplate().find("from TransactionInbound where inboundTimestamp < '" + year+ "-01-01'order by 1 desc limit 2");

        //  Check if archive table exist or not
        List<Object> inboundObj = getHibernateTemplate().find("SHOW TABLES LIKE transaction_outbound");
        List<Object> outboundObj = getHibernateTemplate().find("SHOW TABLES LIKE 'transaction_outbound_archive'");

java.lang.IllegalArgumentException: node to traverse cannot be null! — Jigar Panchal, Jun 07 '17 at 06:21
Please add this piece of information to the question, ideally including the stacktrace. — Markus, Jun 07 '17 at 06:24
Please consider reading to improve your question: https://stackoverflow.com/help/how-to-ask I just tried to help imroving your question. https://stackoverflow.com/help/mcve could also be of help. — Markus, Jun 07 '17 at 06:29
You should not be using Hibernate if you're still thinking in terms of tables and SQL. ORM is intended to let you use objects and forget about the relational model. You're doing it wrong if those two tables don't make to a sensible object. — duffymo, Jun 07 '17 at 09:12
Sounds great. But then how would I get the list of tables in database? — Jigar Panchal, Jun 07 '17 at 09:24

wi2ard · Answer 1 · 2017-06-07T09:36:37.860

The HibernateTemplate::find expects a HQL query in the string parameter and you are passing a native statement. You can do native stuff (queries, statements, etc) using the Session object returned by HibernateTemplate::getSession. To pass a native select query you then have Session::createSQLQuery

BUT do you really want to rely on database specific code to do this? There is a more elegant way to do it by using DatabaseMetaData::getTables. See this answer. And you can get an instance of DatabaseMetaData from a callback method of your HibernateTemplate.

Try this:

        Session session = getHibernateTemplate().getSessionFactory().getCurrentSession();
        if(!session instaceof SessionImpl){
                    //handle this, maybe throw an exception
                }
        else {
            Connection con = (SessionImpl)session.connection();
            ...
        }

Please show me the code to get session from hibernatetemplate. — Jigar Panchal, Jun 07 '17 at 09:21

How to fetch list of tables in database using HibernateDaoSupport?

1 Answers1