topic Re: Concern about JavaDelegate implementations in Alfresco Archive

Concern about JavaDelegate implementations

fwachs — Wed, 05 Dec 2012 23:50:08 GMT

Hi all,I haven't found any documentation or posts about what's the life cycle for the implementations of JavaDelegate.I am worried about this because on my JavaDelegate implementations I create a database connection and use it normally, but i'm not sure what happens next with this instance, does it

Re: Concern about JavaDelegate implementations

ronald_van_kuij — Thu, 06 Dec 2012 06:58:48 GMT

Afaik the documentation states that java delegates should Stateless…

Re: Concern about JavaDelegate implementations

trademak — Thu, 06 Dec 2012 09:21:13 GMT

Right, the Java delegates are stateless, so you definitely close every connection you have opened in the Java logic.

Best regards,

Re: Concern about JavaDelegate implementations

fwachs — Thu, 06 Dec 2012 12:01:35 GMT

Uhm ok then, do you think this is the recommended way to hit an external db ( not the activiti one ) ?

Re: Concern about JavaDelegate implementations

jbarrez — Thu, 06 Dec 2012 16:28:21 GMT

Yes, looks ok at a first glance: opening and closing the connection in the same call.

Re: Concern about JavaDelegate implementations

fwachs — Thu, 06 Dec 2012 16:35:12 GMT

Actually I created a dbcp datasource bean on activiti application context and I pull that bean on the delegate class by calling a static class from activiti.

That's better right?


public abstract class SQLProcessTask extends DataSourceTask implements JavaDelegate {
    protected FixedValue fixedSQL;
    protected JuelExpression expressionSQL;

    public void execute(DelegateExecution execution) {
        this.openDatasource();
        this.executeSQL(execution);
    }

    private void openDatasource() {
        this.datasource = (DataSource) Context.getProcessEngineConfiguration().getBeans().get("dataSource.single");
        this.template = new JdbcTemplate(datasource);
    }

    protected abstract void executeSQL(DelegateExecution execution);

    public void setFixedSQL(FixedValue fixedSQL) {
        this.fixedSQL = fixedSQL;
    }

    public void setExpressionSQL(JuelExpression expressionSQL) {
        this.expressionSQL = expressionSQL;
    }

    public String getSQL(DelegateExecution execution) {
        if (expressionSQL != null) {
            return expressionSQL.getValue(execution).toString();
        } else if (fixedSQL != null) {
            return fixedSQL.getValue(execution).toString();
        }
        return null;
    }
}

Re: Concern about JavaDelegate implementations

jbarrez — Fri, 07 Dec 2012 08:41:32 GMT

Using a connection pool is *always* better 😉