output: #fixed code
                                  @Override
      protected void doSoService(ServiceDataFlowEvent event, DataFlowContext context, JSONObject reqJson) {
  
          //JSONObject outParam = null;
          ResponseEntity<String> responseEntity = null;
          Map<String, String> reqHeader = context.getRequestHeaders();
          String communityId = reqHeader.get("communityId");
          String machineCode = reqHeader.get("machinecode");
          HttpHeaders headers = new HttpHeaders();
          for (String key : reqHeader.keySet()) {
              if (key.toLowerCase().equals("content-length")) {
                  continue;
              }
              headers.add(key, reqHeader.get(key));
          }
          //根据设备编码查询 设备信息
          MachineDto machineDto = new MachineDto();
          machineDto.setMachineCode(machineCode);
          machineDto.setCommunityId(communityId);
          List<MachineDto> machineDtos = machineInnerServiceSMOImpl.queryMachines(machineDto);
          if (machineDtos == null || machineDtos.size() < 1) {
              responseEntity = MachineResDataVo.getResData(MachineResDataVo.CODE_ERROR,"该设备【" + machineCode + "】未在该小区【" + communityId + "】注册");
              context.setResponseEntity(responseEntity);
              return;
          }
          //设备方向
          String direction = machineDtos.get(0).getDirection();
  
          //进入
          if (MACHINE_DIRECTION_IN.equals(direction)) {
              dealCarIn(event, context, reqJson, machineDtos.get(0), communityId);
          } else {
              dealCarOut(event, context, reqJson, machineDtos.get(0), communityId);
          }
      }
input: #vulnerable code 
                                  @Override
      protected void doSoService(ServiceDataFlowEvent event, DataFlowContext context, JSONObject reqJson) {
  
          JSONObject outParam = null;
          ResponseEntity<String> responseEntity = null;
          Map<String, String> reqHeader = context.getRequestHeaders();
          String communityId = reqHeader.get("communityId");
          String machineCode = reqHeader.get("machinecode");
          HttpHeaders headers = new HttpHeaders();
          for (String key : reqHeader.keySet()) {
              if (key.toLowerCase().equals("content-length")) {
                  continue;
              }
              headers.add(key, reqHeader.get(key));
          }
          //根据设备编码查询 设备信息
          MachineDto machineDto = new MachineDto();
          machineDto.setMachineCode(machineCode);
          machineDto.setCommunityId(communityId);
          List<MachineDto> machineDtos = machineInnerServiceSMOImpl.queryMachines(machineDto);
          if (machineDtos == null || machineDtos.size() < 1) {
              outParam.put("code", -1);
              outParam.put("message", "该设备【" + machineCode + "】未在该小区【" + communityId + "】注册");
              responseEntity = new ResponseEntity<>(outParam.toJSONString(), headers, HttpStatus.OK);
              context.setResponseEntity(responseEntity);
              return;
          }
          //设备方向
          String direction = machineDtos.get(0).getDirection();
  
          //进入
          if (MACHINE_DIRECTION_IN.equals(direction)) {
              dealCarIn(event, context, reqJson, machineDtos.get(0), communityId);
          } else {
              dealCarOut(event, context, reqJson, machineDtos.get(0), communityId);
          }
      } 
                              #location 22 
                              #vulnerability type NULL_DEREFERENCE