The ODE integrators now support several step handlers at once, instead of just one. This is more consistent with event handlers management. The setStepHandler method has therefore been replaced by addStephandler, the getStepHandler method has been replaced by getStepHandlers which returns a Collection and a clearStepHandlers method has been added.
commons/proper/math/branches/MATH_2_0/src/java/org/apache/commons/math/ode/sampling/package.html