I have the following problem (using _junit 4.11_): ``` java @ClassRule public static TemporaryFolder tmp = new TemporaryFolder(); ... @Parameters public static Collection<Object[]> data() throws Exception { return java.util.Arrays.asList(new Object[][] { {0, tmp.getRoot().getPath()} }); } ``` This results in **initializationError** ``` java.lang.IllegalStateException: the temporary folder has not yet been created at org.junit.rules.TemporaryFolder.getRoot(TemporaryFolder.java:127) ``` So seems the _@Parameters_ method is executed before the _ClassRule_ initialization phase which makes scenarios like above one a bit complicated.