Java Development

[zidane_143]

Hi All,

I know there are a few threads about this but they appear to be dead. I have attached a very simple and crued application hightlighting my problem.  Click the button and it will start the transactions. 

The problem im having is i am getting large amounts of transaction (batches of  250 transactions) from a server to be applied to a database, inserts updates deletes etc.    It works for a while but will then blow with the out of memory exceptions.  The number of transactions can be reduced but even doing 1 transaction per batch will result in the error.

The application is doing to be used for 5.0 devices and higher any help would be greatly appreciated. 

Cheers

 PS.  I no there is suggestions of using System.gc() but that will that not have major problems on the performs. 

[YamilBracho]

You created a bunch of statements each time you call the execute method. Test change your fieldChanged event to :

public void fieldChanged(Field field, int context) {
	try {
	    database.beginTransaction();
        statement = database.createStatement("INSERT INTO TEST (ID, VALUE) VALUES(?,?)");
        statement.prepare();
		
		label.setText("INSERTING...");
		StringBuffer sb =new StringBuffer();
		for(int i = 0; i < 100000; i++) {
		  sb.append("Value ").append(i);
		
		  st.bind(1, sb.toString());
          st.bind(2, i);
          st.execute();
          st.reset();
		  
		  sb.setlength(6) ; // "Value " length
		}
		st.close();
	    database.commitTransaction();
		database.close();
	  } catch (DatabaseException e) {
		 label.setText(e.getMessage());  
		e.printStackTrace();
	}
}

 HTH

[zidane_143]

Ok i will try that but what if the statements change tables?

Would i have an extra variable inside the statement then for the table name like

INSERT INTO ?  VALUES(?, ?) etc

[YamilBracho]

I think you can not do that. Instead could be something like this:

StringBuffer sb = new StringBuffer(1024);
sb.append("INSERT INTO ").append(tableName);
sb.append(" VALUES(?, ?) ");
String sql = sb.toString();

Maybe you can use a Hashtable to store the fieldname and fieldtype in order to do the field binding and generate the needed "?" in the sql insert statement.

[zidane_143 · Accepted solution]

Hi thanks for the suggestion, i have tried it in the test project and it works, However i tried that in the main project and it failed which leads me to believe their was another problem,

I discovered that there was a scenerio where one of the statements was not being closed off which mean the object was never being destroyed.

Thanks for your help in highlighting this.