apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/ReleaseController.java/ReleaseController/compareRelease
class ReleaseController:  @GetMapping(value = "/envs/{env}/releases/compare")
  public ReleaseCompareResult compareRelease(@PathVariable String env,
                                             @RequestParam long baseReleaseId,
                                             @RequestParam long toCompareReleaseId) {

    return releaseService.compare(Env.valueOf(env), baseReleaseId, toCompareReleaseId);
  }