If you are self-employed, the tax and PRSI you pay is different to that paid by employees. Self-employed people pay PRSI Class S. As such, you will not qualify for Jobseekers Benefit. However, if you worked as an employee for the past 4 years and paid PRSI Class A, then you may have paid enough contributions to claim Jobseekers Benefit.
If you are self-employed and feel you need to claim Jobseekers Allowance, you do not need to close your business to do so.
Jobseeker's Allowance is assessed by a means test, and your income from self-employment is taken into account for this if you are claiming JA while working freelance. The earnings from your business from the previous 12 months count as assessable income, and this figure will then be divided by 52 in order to find your weekly means.