Java Spring HATEOAS RepresentationModel，无法设置属性链接，因为没有setter、wither和it'；它不是持久性构造函数的一部分

目标：我只是尝试在SpringHateOAS应用程序的REST端点上调用get调用。 这是一个以MongoDB为数据库的简单项目

预期结果：当我尝试从REST控制器类调用Get endpoint时，应该返回适当的响应

实际结果：无法调用Get endpoint，使用邮递员调用时会出现内部服务器错误

下面是我试图调用的REST端点

localhost:8086/api/customers

下面是错误响应

{
    "timestamp": "2020-09-01T17:34:28.779+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "message": "",
    "path": "/api/customers"
}

我尝试过的：基本上我的Spring boot应用程序尝试执行客户和订单功能的CRUD操作。 首先，我已经将一些示例数据预加载到mongodb数据库中。当我运行应用程序时，我可以看到来自MongoDB compass的所有数据。 我的应用程序启动时没有任何错误。但当我试图调用任何REST端点时，它会给我一个错误

下面是完整的堆栈跟踪

2020-09-01 23:03:11.446  INFO 15824 --- [           main] com.devzigma.DemoApplication             : Starting DemoApplication on SLL014289 with PID 15824 (D:\Java-excersie\spring-hateoas-baeldung - with mongo\target\classes started by buddhika_jayakodi in D:\Java-excersie\spring-hateoas-baeldung - with mongo)
2020-09-01 23:03:11.449  INFO 15824 --- [           main] com.devzigma.DemoApplication             : No active profile set, falling back to default profiles: default
2020-09-01 23:03:12.192  INFO 15824 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data MongoDB repositories in DEFAULT mode.
2020-09-01 23:03:12.288  INFO 15824 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 91ms. Found 2 MongoDB repository interfaces.
2020-09-01 23:03:12.994  INFO 15824 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8086 (http)
2020-09-01 23:03:13.005  INFO 15824 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2020-09-01 23:03:13.005  INFO 15824 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.37]
2020-09-01 23:03:13.177  INFO 15824 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2020-09-01 23:03:13.177  INFO 15824 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1650 ms
2020-09-01 23:03:13.320  INFO 15824 --- [           main] org.mongodb.driver.cluster               : Cluster created with settings {hosts=[localhost:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms'}
2020-09-01 23:03:13.371  INFO 15824 --- [localhost:27017] org.mongodb.driver.connection            : Opened connection [connectionId{localValue:1, serverValue:164}] to localhost:27017
2020-09-01 23:03:13.375  INFO 15824 --- [localhost:27017] org.mongodb.driver.cluster               : Monitor thread successfully connected to server with description ServerDescription{address=localhost:27017, type=STANDALONE, state=CONNECTED, ok=true, minWireVersion=0, maxWireVersion=9, maxDocumentSize=16777216, logicalSessionTimeoutMinutes=30, roundTripTimeNanos=2701575}
2020-09-01 23:03:14.086  INFO 15824 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2020-09-01 23:03:14.287  INFO 15824 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8086 (http) with context path ''
2020-09-01 23:03:14.298  INFO 15824 --- [           main] com.devzigma.DemoApplication             : Started DemoApplication in 3.483 seconds (JVM running for 4.443)
2020-09-01 23:03:14.338  INFO 15824 --- [           main] org.mongodb.driver.connection            : Opened connection [connectionId{localValue:2, serverValue:165}] to localhost:27017
2020-09-01 23:04:28.673  INFO 15824 --- [nio-8086-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-09-01 23:04:28.673  INFO 15824 --- [nio-8086-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2020-09-01 23:04:28.677  INFO 15824 --- [nio-8086-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 4 ms
2020-09-01 23:04:28.754 ERROR 15824 --- [nio-8086-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: Cannot set property links because no setter, no wither and it's not part of the persistence constructor public com.devzigma.model.Order()!] with root cause

java.lang.IllegalStateException: Cannot set property links because no setter, no wither and it's not part of the persistence constructor public com.devzigma.model.Order()!
    at org.springframework.data.mapping.model.InstantiationAwarePropertyAccessor.setProperty(InstantiationAwarePropertyAccessor.java:118) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.mapping.model.ConvertingPropertyAccessor.setProperty(ConvertingPropertyAccessor.java:63) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readProperties(MappingMongoConverter.java:450) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.populateProperties(MappingMongoConverter.java:367) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:347) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readMap(MappingMongoConverter.java:1187) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:288) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readValue(MappingMongoConverter.java:1580) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter$MongoDbPropertyValueProvider.getPropertyValue(MappingMongoConverter.java:1478) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readProperties(MappingMongoConverter.java:450) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.populateProperties(MappingMongoConverter.java:367) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:347) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:250) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:246) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:98) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate$ReadDocumentCallback.doWith(MongoTemplate.java:3141) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:2788) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2518) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2500) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:856) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:383) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:205) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:55) ~[spring-data-mongodb-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
    at org.springframework.data.repository.core.support.ImplementationInvocationMetadata.invoke(ImplementationInvocationMetadata.java:72) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:382) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:205) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:549) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:155) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:130) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.3.3.RELEASE.jar:2.3.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at com.sun.proxy.$Proxy60.findAll(Unknown Source) ~[na:na]
    at com.devzigma.services.CustomerServiceImpl.allCustomers(CustomerServiceImpl.java:24) ~[classes/:na]
    at com.devzigma.controller.CustomerController.getAll(CustomerController.java:38) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_221]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_221]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.37.jar:9.0.37]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_221]

---

下面是

CustomerController

类

package com.devzigma.controller;

import com.devzigma.model.Customer;
import com.devzigma.model.Order;
import com.devzigma.services.CustomerService;
import com.devzigma.services.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.hateoas.CollectionModel;
import org.springframework.hateoas.Link;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;
import java.util.Optional;

import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.linkTo;
import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.methodOn;

@RestController
@RequestMapping("/api")
public class CustomerController {

    @Autowired
    private CustomerService customerService;

    @Autowired
    private OrderService orderService;

    @GetMapping(value = "/customers/{customerId}")
    public Optional<Customer> getCustomerById(@PathVariable String customerId) {
        return customerService.getCustomerDetail(customerId);
    }

    @GetMapping(value = "/customers")
    public List<Customer> getAll() {
        return customerService.allCustomers();
    }
}

然后是Order.java类

package com.devzigma.model;

import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.hateoas.RepresentationModel;

import java.util.Map;

@Document
public class Customer extends RepresentationModel<Customer> {

    private String customerId;
    private String customerName;
    private String companyName;
    private Map<String, Order> orders;

    public Customer() {
    }

    public Customer(String customerId, String customerName, String companyName) {
        this.customerId = customerId;
        this.customerName = customerName;
        this.companyName = companyName;
    }

    public String getCustomerId() {
        return customerId;
    }

    public void setCustomerId(String customerId) {
        this.customerId = customerId;
    }

    public String getCustomerName() {
        return customerName;
    }

    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }

    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    public Map<String, Order> getOrders() {
        return orders;
    }

    public void setOrders(final Map<String, Order> orders) {
        this.orders = orders;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "customerId='" + customerId + '\'' +
                ", customerName='" + customerName + '\'' +
                ", companyName='" + companyName + '\'' +
                ", orders=" + orders +
                '}';
    }
}

package com.devzigma.model;

import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.hateoas.RepresentationModel;

@Document
public class Order extends RepresentationModel<Order> {

    private String orderId;
    private double price;
    private int quantity;

    public Order() {
    }

    public Order(String orderId, double price, int quantity) {
        this.orderId = orderId;
        this.price = price;
        this.quantity = quantity;
    }

    public String getOrderId() {
        return orderId;
    }

    public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    @Override
    public String toString() {
        return "Order{" +
                "orderId='" + orderId + '\'' +
                ", price=" + price +
                ", quantity=" + quantity +
                '}';
    }
}

我知道这是很多样板代码。但请容忍我。 如果有人能告诉我如何修复上面的错误，那我将不胜感激

---

你好

您确定需要您的实体/模型吗

Customer

和

Order

，从具有属性

私有最终列表链接的
RepresentationModel
类继承

如果你看一下
RepresentationModel.java
，它清楚地表明它是DTO收集链接的基类。，因此我认为它应该用于DTO而不是实体

否则，如果您希望保持如您所述的状态，我看到的避免错误的唯一方法是忽略
链接
字段，使其不被持久化：

重写
链接的getter
将
@Transient
放在
RepresentationModel
类的
links
属性的getter上
它将如下所示：

@Transient
@Override
public Links getLinks() {
    return super.getLinks();
}

如果这种方法不起作用，请尝试为您的实体创建专用DTO，您的每个DTO都将继承自
RepresentationModel
，这样您就可以避免嘈杂的异常并保持整洁
 我尝试使用您在我的Order and Customer类中提到的第二种方法，只需重写getLinks（）方法并使用[at]Transient注释即可。但它给了我同样的错误。正如您提到的第一种方法，那么我应该做的是：将我的实体转换为DTO对吗？没错，您的新DTO将继承自
RepresentationModel
@Abdelghani Roussi，哇，伙计，您救了我一天！非常感谢你。正如您所说，我只是创建了DTO，并使用RepresentationModel对其进行了扩展。
package com.devzigma.repository;

import com.devzigma.model.Order;
import org.springframework.data.mongodb.repository.MongoRepository;

public interface OrderRepository extends MongoRepository<Order, String> {

}

package com.devzigma.services;

import com.devzigma.model.Customer;

import java.util.List;
import java.util.Optional;

public interface CustomerService {

    Optional<Customer> getCustomerDetail(String id);

    List<Customer> allCustomers();
}

package com.devzigma.services;

import com.devzigma.model.Customer;
import com.devzigma.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.*;

@Service
public class CustomerServiceImpl implements CustomerService {

    @Autowired
    private CustomerRepository customerRepository;


    @Override
    public Optional<Customer> getCustomerDetail(String id) {
        return customerRepository.findById(id);
    }

    @Override
    public List<Customer> allCustomers() {
        return customerRepository.findAll();
    }
}

package com.devzigma.services;

import com.devzigma.model.Order;

import java.util.Optional;

public interface OrderService {

    Optional<Order> getAllOrdersForCustomer(String customerId);

}

package com.devzigma.services;

import com.devzigma.model.Order;
import com.devzigma.repository.CustomerRepository;
import com.devzigma.repository.OrderRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.*;

@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private CustomerRepository customerRepository;

    @Autowired
    private OrderRepository orderRepository;

    @Override
    public Optional<Order> getAllOrdersForCustomer(String customerId) {
        return orderRepository.findById(customerId);
    }
}

package com.devzigma;

import com.devzigma.model.Customer;
import com.devzigma.model.Order;
import com.devzigma.repository.CustomerRepository;
import com.devzigma.repository.OrderRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.util.HashMap;

@SpringBootApplication
public class DemoApplication implements CommandLineRunner {

    @Autowired
    private CustomerRepository customerRepository;
    @Autowired
    private OrderRepository orderRepository;

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        customerRepository.deleteAll();
        orderRepository.deleteAll();

        final Customer customer1 = new Customer("10A", "Jane", "ABC Company");
        final Customer customer2 = new Customer("20B", "Bob", "XYZ Company");
        final Customer customer3 = new Customer("30C", "Tim", "CKV Company");

        HashMap<String, Order> cus1order = new HashMap<>();

        cus1order.put("001A", new Order("001A", 150.00, 25));
        cus1order.put("002A", new Order("002A", 250.00, 15));

        customer1.setOrders(cus1order);

        customerRepository.save(customer1);
        customerRepository.save(customer2);
        customerRepository.save(customer3);

    }
}

server.port=8086
spring.data.mongodb.authentication-database=admin
spring.data.mongodb.uri=mongodb://localhost:27017/customer-order

@Transient
@Override
public Links getLinks() {
    return super.getLinks();
}