DbConnection.java

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package edu.msu.nscl.olog;

import javax.naming.InitialContext;
import javax.sql.DataSource;

/**
 *
 * @author berryman
 */
public class DbConnection {
    private static ThreadLocal<DbConnection> instance = new ThreadLocal<DbConnection>() {

        @Override
        protected DbConnection initialValue() {
            return new DbConnection();
        }
    };
    private static final String dbResourceName = "jdbc/olog";
    private DataSource ds;

    private DbConnection() {
        try {
            InitialContext ic = new InitialContext();
            ds = (DataSource) ic.lookup("java:comp/env/" + dbResourceName);
        } catch (Exception e) {
            throw new IllegalStateException("Cannot find JDBC DataSource '"
                    + dbResourceName + "'", e);
        }
    }

    /**
     * Returns the DbConnection instance.
     *
     * @return DbConnection instance
     */
    public static DbConnection getInstance() {
        return instance.get();
    }

    /**
     * Returns the DataSource Connection, requesting a new one (thread local) if needed.
     *
     * @return Connection to the JDBC DataSource
     * @throws OlogException wrapping an SQLException
     */
    public DataSource getDataSource() throws OlogException {
        return ds;
    }
}