如何使用来自 spring-data-rest 的实体响应列表答案

【问题标题】：How to consume list of entities response from spring-data-rest如何使用来自 spring-data-rest 的实体响应列表
【发布时间】：2017-02-22 13:48:29
【问题描述】：

我正在使用 spring-data-rest 来公开 REST API。我的一种搜索方法返回实体列表。仓库和rest响应如下

List<Order> findByKeywordContaining(String keyword);

搜索响应：

{  
   "_embedded":{  
      "orders":[  
         {  
            "keyword":"Iron mattress",
            "name":"Hostel",
            "_links":{  
               "self":{  
                  "href":"http://localhost:8081/orders/2"
               },
               "order":{  
                  "href":"http://localhost:8081/orders/2"
               }
            }
         },
         {  
            "keyword":"Iron",
            "name":"Weat strong",
            "_links":{  
               "self":{  
                  "href":"http://localhost:8081/orders/40"
               },
               "order":{  
                  "href":"http://localhost:8081/orders/40"
               }
            }
         }
      ]
   },
   "_links":{  
      "self":{  
         "href":"http://localhost:8081/orders/search/findByKeywordContaining?keyword=iron"
      }
   }
}

现在我正在使用 RestTemplate 将此响应消费到客户端的进程中，如下所示

List<Order> orders = restOperations.exchange(new URI(url), HttpMethod.GET, null, new ParameterizedTypeReference<Resource<List<Order>>>() {}).getBody().getContent();

上面的代码对于响应中的单个对象可以正常工作，但是如果响应包含多个对象。代码抛出如下错误

org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Unrecognized field "_embedded" (class org.springframework.hateoas.Resource), not marked as ignorable (3 known properties: , "links", "content", "page"])
at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@6a2bc870; line: 2, column: 18] (through reference chain: org.springframework.hateoas.Resource["_embedded"]); nested exception is com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "_embedded" (class org.springframework.hateoas.Resource), not marked as ignorable (3 known properties: , "links", "content", "page"])

我在这里缺少什么？如何将上述响应作为 List 使用？

Order.java

public class Order {
private int id;
private String name;
private String keyword;
private Agent agent;

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getKeyword() {
    return keyword;
}

public void setKeyword(String keyword) {
    this.keyword = keyword;
}

public Agent getAgent() {
    return agent;
}

public void setAgent(Agent agent) {
    this.agent = agent;
}

完整的错误堆栈

21:39:30.746 [http-bio-8080-exec-36] DEBUG c.o.x.o.accessor.XWorkMethodAccessor - Error calling method through OGNL: object: [com.ams.order.actions.ViewOrderSearchAction@5218c8df] method: [viewOrderSearch] args: [[]]
org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Unrecognized field "_embedded" (class org.springframework.hateoas.Resource), not marked as ignorable (2 known properties: , "links", "content"])
 at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@7583f177; line: 2, column: 18] (through reference chain: org.springframework.hateoas.Resource["_embedded"]); nested exception is com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "_embedded" (class org.springframework.hateoas.Resource), not marked as ignorable (2 known properties: , "links", "content"])
 at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@7583f177; line: 2, column: 18] (through reference chain: org.springframework.hateoas.Resource["_embedded"])
    at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readJavaType(MappingJackson2HttpMessageConverter.java:181) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.read(MappingJackson2HttpMessageConverter.java:173) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:94) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:724) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:709) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:527) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:482) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:455) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at com.ams.service.OrderSearcherImpl.searchForName(OrderSearcherImpl.java:49) ~[classes/:na]
    at com.ams.order.actions.ViewOrderSearchAction.viewOrderSearch(ViewOrderSearchAction.java:61) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:891) [ognl-3.0.6.jar:na]
    at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1293) [ognl-3.0.6.jar:na]
    at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68) ~[ognl-3.0.6.jar:na]
    at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:117) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:108) [xwork-core-2.3.20.jar:2.3.20]
    at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1369) [ognl-3.0.6.jar:na]
    at ognl.ASTMethod.getValueBody(ASTMethod.java:90) [ognl-3.0.6.jar:na]
    at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) [ognl-3.0.6.jar:na]
    at ognl.SimpleNode.getValue(SimpleNode.java:258) [ognl-3.0.6.jar:na]
    at ognl.Ognl.getValue(Ognl.java:494) [ognl-3.0.6.jar:na]
    at ognl.Ognl.getValue(Ognl.java:458) [ognl-3.0.6.jar:na]
    at com.opensymphony.xwork2.ognl.OgnlUtil$2.execute(OgnlUtil.java:309) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecute(OgnlUtil.java:340) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:307) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:423) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:287) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:250) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) [struts2-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) [xwork-core-2.3.20.jar:2.3.20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) [xwork-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) [struts2-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564) [struts2-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81) [struts2-core-2.3.20.jar:2.3.20]
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) [struts2-core-2.3.20.jar:2.3.20]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.67]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.67]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:186) [spring-security-web-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.2.4.RELEASE.jar:3.2.4.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343) [spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260) [spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.67]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.67]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.67]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.67]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) [catalina.jar:7.0.67]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [catalina.jar:7.0.67]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) [catalina.jar:7.0.67]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) [catalina.jar:7.0.67]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) [catalina.jar:7.0.67]
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) [catalina.jar:7.0.67]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [catalina.jar:7.0.67]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) [catalina.jar:7.0.67]
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) [tomcat-coyote.jar:7.0.67]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625) [tomcat-coyote.jar:7.0.67]
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318) [tomcat-coyote.jar:7.0.67]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_101]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_101]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-coyote.jar:7.0.67]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101]
Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "_embedded" (class org.springframework.hateoas.Resource), not marked as ignorable (2 known properties: , "links", "content"])
 at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@7583f177; line: 2, column: 18] (through reference chain: org.springframework.hateoas.Resource["_embedded"])
    at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:79) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty(DeserializationContext.java:555) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:708) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1160) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:315) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2888) ~[jackson-databind-2.2.2.jar:2.2.2]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2094) ~[jackson-databind-2.2.2.jar:2.2.2]
    at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readJavaType(MappingJackson2HttpMessageConverter.java:178) ~[spring-web-3.2.17.RELEASE.jar:3.2.17.RELEASE]
    ... 105 common frames omitted

【问题讨论】：

你能展示你的 Order 类吗？
更新了有问题的订单类信息
@DerickDaniel 有什么想法吗？？？
不知道这是否能解决您的问题，但似乎无法从 rest 模板返回列表，只能返回数组：javaspringframeworkcourse.wordpress.com/2015/08/06/…。也许你可以试试。
@Achaius 看到我的回答

标签： spring jackson spring-data-rest spring-hateoas

【解决方案1】：

问题是您的 Order 类没有根据响应映射所有字段，因此如果您不想要所有字段，请在 Order 类中使用 Jackson 的注释忽略它们 -

    @JsonIgnoreProperties(ignoreUnknown = true)
    public class Order {
    ...
    }

编辑：创建您的响应类，如下所示（您可以根据您的 json 响应进行编辑）-

class Response{
    @JsonProperty("_embedded")
    private Embedded embedded;

    public Embedded getEmbedded() {
        return embedded;
    }

    public void setEmbedded(Embedded embedded) {
        this.embedded = embedded;
    }
}


class Embedded{
    @JsonProperty("orders")
    List<Order> orders = new ArrayList<Order>();

    public Embedded(){

    }

    public List<Order> getOrders() {
        return orders;
    }

    public void setOrders(List<Order> orders) {
        this.orders = orders;
    }
}


class Order {
    private int id;
    private String name;
    private String keyword;
    private Agent agent;

    @Override
    public String toString() {
        return "Order [id=" + id + ", name=" + name + ", keyword=" + keyword + "]";
    }

    public Order(){

    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getKeyword() {
        return keyword;
    }

    public void setKeyword(String keyword) {
        this.keyword = keyword;
    }


    public Agent getAgent() {
        return agent;
    }

    public void setAgent(Agent agent) {
        this.agent = agent;
    }

}

由于响应包含在根注_embedded中，因此必须考虑并使用@JsonProperty进行注释，以便可以识别

获取如下响应对象 -

Response reeponse = restOperations
                .exchange(new URI(url), HttpMethod.GET, null, new ParameterizedTypeReference<Response>() {
                }).getBody().getContent();

【讨论】：

我仍然有同样的问题。
得到与问题中提到的相同的错误
这是唯一的方法。因为响应是标准的 spring-hateoas 格式。我可以使用来自 hateoas 的一些包装类而不是编写这个 Response 类。因为我需要更多具有不同对象的嵌入式类，如订单、代理等，
不确定其他方式，但在这里您可以调整响应类以包含您想要的所有对象并使用 @JsonInclude(JsonInclude.Include.NON_NULL) 注释来避免响应中不存在的对象字段.
这是一个 hack，但我认为它仍然有助于帮助人们了解问题的根源。然而，最好使用带有参数化类型引用的 org.springframework.hateoas.Resources 类将 hatoas 响应转换为对象。

【解决方案2】：

您应该能够进行完全相同的restTemplate.exchange() 调用，但对实体集合使用org.springframework.hateoas.Resources 包装类，而不是对单个实体使用org.springframework.hateoas.Resource 包装类。 IE。 new ParameterizedTypeReference<Resources<Order>>() {} 作为第四个参数。

请注意，如果您收到此调用返回的包装空集合但没有记录错误，请确保您具有 org.springframework.data:spring-data-rest-core 依赖项 - 我和另一个开发人员刚刚花费今天大部分时间都在调试这个！

（这有帮助：http://www.java-allandsundry.com/2014/01/consuming-spring-hateoas-rest-service.html）

【讨论】：

【解决方案3】：

我通过使用 spring-hateoas Traverson 而不是 RestTempalte 解决了这个问题。这符合我的预期。

【讨论】：

你能举个例子吗？谢谢

【解决方案4】：

让 Jackson 解散到Resources<Resource<Order>>。这将捕获集合的链接以及每个订单的链接。

【讨论】：

【解决方案5】：

在当前版本的 Spring Data 中，您显示的响应类型由 org.springframework.hateoas.CollectionModel 建模。

因此，将响应类型更改为CollectionModel<Order>，并使用.getContent() 检索Collection 的项目（而不是列表）。

Collection<Order> orders = restOperations.exchange(new URI(url), HttpMethod.GET, null, new CollectionModel<Order>() {}).getBody().getContent();

【讨论】：