在spring和mongodb的形式中使用sign有新的情况findOne中的错误

Question

@RestController
@RequestMapping("/enduser")

public class enduserRestCountroller {
    
    @Autowired
    enduserRepository enduserRepository;
    MongoOperations mongoOperations;
    
     //create
    @RequestMapping(method = RequestMethod.POST,consumes = MediaType.APPLICATION_JSON_VALUE)
    public void create(@RequestBody enduser enduser){
    enduserRepository.save(enduser);
    }
    
    
    @RequestMapping(value = "/list", method = RequestMethod.GET)
    
    public List<enduser> readall(  ){
    return enduserRepository.findAll();
    }

    @RequestMapping(value = "/{id}" ,method=RequestMethod.GET)

    @ResponseStatus(HttpStatus.OK)

    @CrossOrigin

    public @ResponseBody enduser read(@PathVariable String id){
    return enduserRepository.findOne(id);
    }
    
    @RequestMapping(method = RequestMethod.PUT,consumes = MediaType.APPLICATION_JSON_VALUE)
    public void update(@RequestBody enduser enduser){
        enduserRepository.save(enduser);
    }
    
    @RequestMapping(value = "/deleteuser/{id}",method=RequestMethod.GET)
    public String delete(@PathVariable String id){
        enduserRepository.delete(id);
        return "1";
    }
    
    @RequestMapping(value = "/signin/{username}",method=RequestMethod.GET)
    public enduser login(@PathVariable String username){
         
        System.out.println(username);
         
        username="maged";
        
        Query query=new Query();
        
        enduser user=mongoOperations.
                findOne(
                        query.addCriteria(
                                Criteria.where("username")
                                        .is(username)),enduser.class);
        
        System.out.println("enduser is "+user.getUsername());
        return user;
    }
}

未定义的2017-10-03 13:24:11.353错误5668---[io-8080-exec-10]O.A.C.C.C.[.[.[/].[dispatcherServlet]:servlet.Service（）在路径[]上下文中的servlet[dispatcherServlet]引发异常[html" target="_blank">请求处理失败；嵌套异常是java.lang.NullPointerException]

java.lang.nullPointerException：com.adams.demo.restController.endUserRestCountroller.login(endUserRestCountroller.java:84)~[classes/:na]

Answer 1

看起来您似乎缺少了MongoOperations的@autowired注释：

@Autowired
enduserRepository enduserRepository;
@Autowired
MongoOperations mongoOperations;

您还应该尝试将逻辑与控制器分离，并将类的Java命名约定与用户分离。

您可以在这里找到一个工作示例：

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