Java Spring数据REST端点消失（休眠冲突）

我正在尝试将我的项目更新到SpringBoot2.0.5版本。这是 简单的

基本部分：

@Entity
@Table(name = "placement")
public class Placement {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(updatable = false)
    private Long id;

    private String name;

    @ManyToOne(fetch=FetchType.LAZY, cascade = CascadeType.REMOVE)
    private PlacementType type;

    //... getters and setters
}

@Entity
@Table(name = "placement_type")
public class PlacementType  {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(updatable = false)
    private Long id;

    private String name;
    //... getters and setters
}

@RepositoryRestResource(collectionResourceRel = "placement", path = "placement")
public interface PlacementRepository extends 
     PagingAndSortingRepository<Placement, Long> {}

@RepositoryRestResource(collectionResourceRel = "placementType", path = "placementType")
public interface PlacementTypeRepository extends 
     PagingAndSortingRepository<PlacementType, Long> {}

问题：

启动应用程序时，两个api端点都可以正常工作：

GET http://localhost:8090/api/placement/ => 200 works fine
GET http://localhost:8090/api/placementType => 200 works fine

但从Placement uri（

@ManyToOne

）访问PlacementType后，我无法再访问PlacementType端点：

GET http://localhost:8090/api/placement/1/type => 200 works fine
GET http://localhost:8090/api/placementType => 404 (and default spring error screen)

没有错误日志，或者我的日志级别不正确，但我不知道为什么请求会被重定向到SimpleRhlHandlerMapping第二次

 LOG from first GET http://localhost:8090/api/placementType => 200 
 02:38:56.076 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/api/placementType] 
 02:38:56.080 [http-ni] DEBUG s.w.s.m.m.a.RequestMappingHandlerMapping - Looking up handler method for path /api/placementType 
 02:38:56.088 [http-ni] DEBUG s.w.s.m.m.a.RequestMappingHandlerMapping - Did not find handler method for [/api/placementType] 
 02:38:56.114 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Last-Modified value for [/api/placementType] is: -1 
 Hibernate: select placementt0_.id as id1_1_, placementt0_.name as name2_1_ from placement_type placementt0_ limit ?
 02:38:56.559 [http-ni] DEBUG m.m.a.RequestResponseBodyMethodProcessor - Written [PagedResource { content: [Resource { content: com.varren.model.PlacementType@65e962bd, links: [<http://localhost:8090/api/placementType/1>;rel="self", <http://localhost:8090/api/placementType/1>;rel="placementType"] }], metadata: Metadata { number: 0, total pages: 1, total elements: 1, size: 20 }, links: [<http://localhost:8090/api/placementType{?page,size,sort}>;rel="self", <http://localhost:8090/api/profile/placementType>;rel="profile"] }] as "application/hal+json" using [org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration$ResourceSupportHttpMessageConverter@446c8c72] 
 02:38:56.562 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling 
 02:38:56.563 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Successfully completed request 

                 GET http://localhost:8090/api/placement/1/type => 200 works fine
 LOG from second GET http://localhost:8090/api/placementType => 404 
 03:09:08.285 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/api/placementType] 
 03:09:08.286 [http-ni] DEBUG s.w.s.m.m.a.RequestMappingHandlerMapping - Looking up handler method for path /api/placementType 
 03:09:08.287 [http-ni] DEBUG s.w.s.m.m.a.RequestMappingHandlerMapping - Did not find handler method for [/api/placementType] 
 03:09:08.292 [http-ni] DEBUG o.s.w.s.h.SimpleUrlHandlerMapping        - Matching patterns for request [/api/placementType] are [/**] 
 03:09:08.292 [http-ni] DEBUG o.s.w.s.h.SimpleUrlHandlerMapping        - URI Template variables for request [/api/placementType] are {} 
 03:09:08.292 [http-ni] DEBUG o.s.w.s.h.SimpleUrlHandlerMapping        - Mapping [/api/placementType] to HandlerExecutionChain with handler [ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/], ServletContext resource [/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@74eec640]]] and 1 interceptor 
 03:09:08.293 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Last-Modified value for [/api/placementType] is: -1 
 03:09:08.294 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling 
 03:09:08.294 [http-ni] DEBUG o.s.w.s.DispatcherServlet                - Successfully completed request 

从第一次获取日志http://localhost:8090/api/placementType => 200 
02:38:56.076[http ni]调试o.s.w.s.DispatcherServlet-名为“DispatcherServlet”的DispatcherServlet正在处理[/api/placementType]的GET请求
02:38:56.080[http ni]调试s.w.s.m.m.a.RequestMappingHandlerMapping-查找路径/api/placementType的处理程序方法
02:38:56.088[http ni]调试s.w.s.m.a.RequestMappingHandlerMapping-未找到[/api/placementType]的处理程序方法
02:38:56.114[http ni]调试o.s.w.s.DispatcherServlet-[/api/placementType]的上次修改值为：-1
休眠：从placement类型placementt0\uLimit中选择placementt0\uId作为id1\u1\uId，placementt0\uName作为name2\u1\uId？
02:38:56.559[http ni]调试m.m.a.RequestResponseBodyMethodProcessor-编写[PagedResource{content:[Resource{content:com.varren.model。PlacementType@65e962bd，链接：[；rel=“self”，；rel=“placementType”]}]，元数据：元数据{number:0，总页数：1，总元素数：1，大小：20}，链接：[；rel=“self”，；rel=“profile”]}]as使用[org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration]的“application/hal+json”$ResourceSupportHttpMessageConverter@446c8c72] 
02:38:56.562[http ni]调试o.s.w.s.DispatcherServlet-返回给名为“DispatcherServlet”的DispatcherServlet的Null ModelAndView:假设HandlerAdapter完成了请求处理
02:38:56.563[http ni]调试o.s.w.s.DispatcherServlet-已成功完成请求
得到http://localhost:8090/api/placement/1/type =>200工作正常
从第二个开始记录http://localhost:8090/api/placementType => 404 
03:09:08.285[http ni]调试o.s.w.s.DispatcherServlet-名为“DispatcherServlet”的DispatcherServlet正在处理[/api/placementType]的GET请求
03:09:08.286[http ni]调试s.w.s.m.m.a.RequestMappingHandlerMapping-查找路径/api/placementType的处理程序方法
03:09:08.287[http ni]调试s.w.s.m.a.RequestMappingHandlerMapping-未找到[/api/placementType]的处理程序方法
03:09:08.292[http ni]调试o.s.w.s.h.SimpleUrlHandlerMapping-请求[/api/placementType]的匹配模式为[/**]
03:09:08.292[http ni]调试o.s.w.s.h.SimpleUrlHandlerMapping-请求[/api/placementType]的URI模板变量为{}
03:09:08.292[http ni]调试o.s.w.s.h.SimpleUrlHandlerMapping-使用handler[ResourceHttpRequestHandler[locations=[class path resource[META-INF/resources/]，class path resource[resources/]，class path resource[static/]，class path resource[public/]，ServletContext resource[/]将[/api/placementType]映射到HandlerExecutionChain，resolvers=[org.springframework.web.servlet.resource。PathResourceResolver@74eec640]]]和1个拦截器
03:09:08.293[http ni]调试o.s.w.s.DispatcherServlet-[/api/placementType]的上次修改值为：-1
03:09:08.294[http ni]调试o.s.w.s.DispatcherServlet-返回给名为“DispatcherServlet”的DispatcherServlet的Null ModelAndView:假设HandlerAdapter已完成请求处理
03:09:08.294[http ni]调试o.s.w.s.DispatcherServlet-已成功完成请求

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还有一件事。大多数时候我都有这个bug，但有时一切都正常。我在github repo中添加了第二个@Entity，以表明有时两个相同的实体中的一个可以工作，另一个不能工作，但可能我遗漏了一些明显的问题，看起来问题出在不推荐的

hibernate entitymanager中，或者至少是一个版本不匹配

compile group: 'org.hibernate', name: 'hibernate-entitymanager', version: '5.3.6.Final'

我花了几天时间才意识到不再需要它，我应该切换到
hibernate core
。但是切换到最新的hibernate core也产生了同样的问题，所以我必须完全删除依赖项，让
spring boot starter数据jpa
使用它的版本（
5.2.17.最终版
用于启动
2.0.5.发行版
）

在
RepositoryRestHandlerMapping.lookupHandlerMethod
中使用断点对此进行了调试，并在RepositoryRestHandlerMapping缓存中注意到奇怪的
class com.varren.model.PlacementType$HibernateProxy


正常（工作）版本如下所示（没有HibernateProxy）：
非常奇怪。我现在唯一要尝试的是将属性名称从
PlacementType；
更改为
PlacementType PlacementType；
@Patrick是的，尝试了几次。还测试了几个java版本。切换到boot 2.0.6。经过几天的调试，我觉得使用最新版本太愚蠢了属于休眠entitymanager

，并且从不尝试删除依赖项。

compile group: 'org.hibernate', name: 'hibernate-entitymanager', version: '5.3.6.Final'