// TODO: Replace ArrayList with List interface
    public static ArrayList<String> getColumns(Connection conn, String schemaName, String tableName ) throws SQLException {
        // TODO: Diamont operator is needed 
        ArrayList<String> fields = new ArrayList<String>();
        DatabaseMetaData meta = conn.getMetaData();
        ResultSet rsetCol = meta.getColumns( null, schemaName, tableName, null );
        while (rsetCol.next() ) {
            String colName = rsetCol.getString(4);
            fields.add( colName );
        }
        rsetCol.close();
        return fields;
    }
    
    // TODO: ArrayList again
    public static String formatOutput( ArrayList<String> fields, ResultSet rset ) throws SQLException {
        StringBuilder res;
        res = new StringBuilder();
        int pos = 1;
        // TODO: Not sure is it good idea to simulate JSon with StringBuilder. No escaping.
        res.append( "{ " );

        System.out.println( "Search in table "+schemaName+"."+tableName );
        System.out.println( "sql="+sql.toString() );
        // TODO: There is no need to prepare statement. Try to use Statement with trivial query.
        PreparedStatement stmt;
        stmt = conn.prepareStatement( sql.toString() );
        int pos = 1;
        for ( String s:fields ) {
            stmt.setString( pos++, "%"+subStr+"%" );
        }
        ResultSet rset = stmt.executeQuery();
        while ( rset.next() ) {
            System.out.println( formatOutput( fields, rset ) );
        }
        // TODO: Hm... What's about try-with-resources?
        rset.close();
        stmt.close();
        System.out.println( "search finished" );