A federal judge has upheld a decision striking down a Florida law that forces welfare recipients to pass a drug test. The measure barred applicants who test positive for drug use from receiving government assistance for one year or until they complete a drug abuse program. On Wednesday, Judge Mary Scriven sided with previous rulings that found the law violates constitutional protections against unreasonable searches and seizures. Figures from a period when the law was briefly in effect showed the testing turned up a less than 2 percent drug use rate among welfare recipients, far less than the rate for the general population at 8 percent. The law ended up losing money for the state because the high cost of the testing exceeded the low savings from denying benefits.