how to convert ArrayList<String>to sumthing that suite in sql

[sk said]

Hi all,
i got a problem on converting ArrayList<String>. Since i cant use the ArrayList in sql.

i want to update `result` column in sql using preparedStatement.since the `result` parameter is LongBlob.and ArrayList<String> result_list=[apple, mango, banana, orange, grape,]

i want to store all the list in result_list into `result`.means i have to convert and type map.but, i dont know how to do it.
Anyone knows how to do it?

[Vijitha Kumara]

Welcome to CodeRanch, SK Said

Can you show us what you have done so far, and the error you get...?

[sk said]

Vijitha Kumara wrote:Welcome to CodeRanch, SK Said

Can you show us what you have done so far, and the error you get...?

Thanks VK...

This is code dat ive done so far

private void update(ArrayList<String> list, int uid)
	   {

            //count data in list
            int i;
            for (Iterator it = list.iterator(); it.hasNext();)
                      {
					i++;
		       }
            //convert ArrayList to Array
            String []list_result = new String[i];
            list.toArray(list_result);

	          try
	             	{
	                	Connection con=null;


	          			Class.forName ("com.mysql.jdbc.Driver").newInstance ();
	          			con= DriverManager.getConnection("jdbc:mysql://localhost/t-way","root","");


	          			PreparedStatement ps = con.prepareStatement("UPDATE `input` SET `check`=1, `result`=?  WHERE `check`=0 AND `userid`=?");
						ps.setArray(1,list_result);
						ps.setInt(2,uid);
						ps.executeUpdate();


	          			ps.close();
	          			con.close();

	      			}

	          catch (Exception e)
	         		{
	             		System.err.println ("Cannot connect to database server "+ e.getMessage());
	         		}
       }

example of ArrayList<String> list= [Apple+lemon, Apple+grape, Apple+banana, Apple+vanila,]

[Rob Spoor]

LongBlob means you can store any binary data in there. That includes serialized objects; you could get an OutputStream from the PreparedStatement, wrap that in an ObjectOutputStream, than write the ArrayList to that. Don't forget to close the ObjectOutputStream or the serialization footer won't be present.

One major drawback with this approach: if the class changes and you haven't prepared for that properly (e.g. with a fixed serialVersionUid field) you will get an exception when getting the data back from the database.