In jbpm3.X ,we could define private variable and general variable ,but in jbpm4.x, i coudn't find this function.

   i found there are two methods to create variable in jbpm4.x

   one method:

   executionService.setVariable(executionId, name, value)

two method:
   taskService.setVariables(taskId, variables)

  so i made a experiment,i define a workflow with two task nodes ,in task1 node, i create one  variables like that:

taskService.setVariables(task1.getId(), "var1");

  in task2 node,i think i shouldn't get the var1 which created in task1

  but  i was suprised  when i user this code

taskService.getVariable(task2.getId(), "var1")

the result is i could get variable var1 in task2

so ,how could i create a variable only exist in one task ?

my spoken english is little poor,thansk all..