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如何解决Fortify竞赛条件：Singleton Member Field问题

问题内容：

我遇到问题了。我们在我的项目中使用Spring MVC框架，但是Spring MVC的默认Controller是Singleton
Model。我通过会话更改Controller使用@Scope（“ session”）以避免出现竞争状况问题（每个人都有自己的Controller）。

@Controller
@Scope("session")
public class AP0Controller extends BaseController {

    @Autowired
    GnRecService gnRecService;

    Integer seq = null;//Global variable

    @RequestMapping(value = "/agn/AP1W01A_004", method=RequestMethod.GET)
    public ModelAndView welcomeGrid(@RequestParam("payType")String payType){
        seq = gnRecService.findTheLastPK(payType);
        ModelAndView view = new ModelAndView(".agn.AP1W01A_004");
        return view;
    }

    public ModelAndView showPk() {
        seq +=2; 
        ModelAndView view = new ModelAndView(".agn.AP1W01A_004");
        view.addObject("seq",seq)
        return view;
    }

}

经过HP Fortify扫描后，报告指出这将导致竞态条件。如何解决并解决问题？

seq +=2;//Race Condition: Singleton Member Field

问题答案：

尝试重新设计控制器，使其不进入状态。另外，您可以考虑使用AtomicInteger

AtomicInteger seq = new AtomicInteger();//Global variable

@RequestMapping(value = "/agn/AP1W01A_004", method=RequestMethod.GET)
    public ModelAndView welcomeGrid(@RequestParam("payType")String payType){
        seq.set(gnRecService.findTheLastPK(payType));
        ModelAndView view = new ModelAndView(".agn.AP1W01A_004");
        return view;
    }

    public ModelAndView showPk() {
        final int localSeq = seq.addAndGet(2); 
        ModelAndView view = new ModelAndView(".agn.AP1W01A_004");
        view.addObject("seq",localSeq)
        return view;
    }