protected static Method getMethod(Class<?> clazz, String methodName, Class<?>... parameterTypes) {
    if (clazz == null) {
      return null;
    }
    try {
      return clazz.getMethod(methodName, parameterTypes);
    } catch (SecurityException e) {
      log.error("Security exception looking for method " + clazz.getName() + "." + methodName + ".  Cause: " + e);
      return null;
    } catch (NoSuchMethodException e) {
      log.error("Method not found " + clazz.getName() + "." + methodName + "." + methodName + ".  Cause: " + e);
      return null;
    }
  }
Get a method by name and parameter types. If the method is not found then return null.

@param clazz The class to which the method belongs.
@param methodName The name of the method.
@param parameterTypes The types of the parameters accepted by the method.
src/main/java/org/apache/ibatis/io/VFS.java