java.util.Currency 的 Mongo spring-data 问题答案

【问题标题】：Mongo spring-data issue with java.util.Currencyjava.util.Currency 的 Mongo spring-data 问题
【发布时间】：2016-05-11 08:17:43
【问题描述】：

收到错误“在实体类 java.util.Currency 上找不到属性 null”

嗨，我有文档类

@Document
@JsonInclude(Include.NON_NULL)
public class Course {
    @Id
    private String id;
    private String title;
    private Currency curr;

    public String getId() {
        return id;
    }

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

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Currency getCurr() {
        return curr;
    }

    public void setCurr(Currency curr) {
        this.curr = curr;
    }

}

当使用数据向我的服务发出 POST 请求时

{"title":"my title","curr":"INR"}

我得到响应

 {
   "id": "56b0aa010364310e094c5f30",
   "title": "my title",
   "curr": "INR"
 }

但是当我做 GET 我得到错误

: Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.data.mapping.model.MappingException: No property null found on entity class java.util.Currency to bind constructor parameter to!] with root cause
org.springframework.data.mapping.model.MappingException: No property null found on entity class java.util.Currency to bind constructor parameter to!

和响应为

{
   "timestamp": 1454419040321,
   "status": 500,
   "error": "Internal Server Error",
   "exception": "org.springframework.data.mapping.model.MappingException",
   "message": "No property null found on entity class java.util.Currency to bind constructor parameter to!",
   "path": "/56b0aa010364310e094c5f30"

}

我使用的是 SpringBoot 1.3.2，Jackons 版本是 2.6.5

stackoverflow 上有类似的问题，但已被删除。我做错了什么？

完整的堆栈跟踪

org.springframework.data.mapping.model.MappingException: No property null found on entity class java.util.Currency to bind constructor parameter to!
at org.springframework.data.mapping.model.PersistentEntityParameterValueProvider.getParameterValue(PersistentEntityParameterValueProvider.java:74) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.mapping.model.SpELExpressionParameterValueProvider.getParameterValue(SpELExpressionParameterValueProvider.java:63) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.convert.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:71) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.convert.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:83) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:251) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:231) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readValue(MappingMongoConverter.java:1186) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.access$200(MappingMongoConverter.java:78) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$MongoDbPropertyValueProvider.getPropertyValue(MappingMongoConverter.java:1134) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.getValueInternal(MappingMongoConverter.java:870) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$1.doWithPersistentProperty(MappingMongoConverter.java:283) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter$1.doWithPersistentProperty(MappingMongoConverter.java:271) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:309) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:271) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:231) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:191) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:187) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:78) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.MongoTemplate$ReadDbObjectCallback.doWith(MongoTemplate.java:2224) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.MongoTemplate.executeFindOneInternal(MongoTemplate.java:1855) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.MongoTemplate.doFindOne(MongoTemplate.java:1672) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.core.MongoTemplate.findById(MongoTemplate.java:614) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findOne(SimpleMongoRepository.java:119) ~[spring-data-mongodb-1.8.2.RELEASE.jar:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_66]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_66]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_66]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_66]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:483) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:468) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:440) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.11.2.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208) ~[spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at com.sun.proxy.$Proxy125.findOne(Unknown Source) ~[na:na]
at com.wiziq.microservice.course.service.CourseService.getCourseById(CourseService.java:16) ~[classes/:na]
at com.wiziq.microservice.course.controller.CourseController.getCourseById(CourseController.java:24) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_66]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_66]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_66]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_66]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845) ~[spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(EndpointWebMvcAutoConfiguration.java:237) ~[spring-boot-actuator-1.3.2.RELEASE.jar:1.3.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.cloud.sleuth.instrument.web.TraceFilter.doFilterInternal(TraceFilter.java:148) ~[spring-cloud-sleuth-core-1.0.0.M4.jar:1.0.0.M4]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:111) ~[spring-boot-actuator-1.3.2.RELEASE.jar:1.3.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:87) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:103) ~[spring-boot-actuator-1.3.2.RELEASE.jar:1.3.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) ~[tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) [tomcat-embed-core-8.0.30.jar:8.0.30]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) [tomcat-embed-core-8.0.30.jar:8.0.30]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_66]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_66]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.0.30.jar:8.0.30]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_66]

【问题讨论】：

我看到 jackson 添加了对 java.util.currency github.com/FasterXML/jackson/wiki/Jackson-Release-2.5.1 的支持
我认为你只是从你的 json 中取回一个字符串而不是一个货币对象。如果将 Currency 更改为 String 是否有效？
发布整个堆栈跟踪。
添加了完整的堆栈跟踪
我将 Currency 更改为字符串并得到响应为 { "id": "56b0b1460364f174f6204389", "title": "courseY_YYYY______", "curr": "{ \"currencyCode\" : \"INR\ " , \"defaultFractionDigits\" : 2 , \"numericCode\" : 356}", "createdDate": 1454420294250, "updatedDate": 1454420294250 }

标签： java spring jackson spring-data spring-data-mongodb

【解决方案1】：

以防万一其他人遇到@oliver-gierke 的答案并像@kaluva 一样得到 NullPointerException

Spring 的类型解析器似乎对 Lambda 表达式有问题。只需将 bean 定义更改为：

@Bean
public CustomConversions customConversions() {
    Converter<Currency, String> currencyToString = new Converter<Currency, String>() {
        @Override
        public String convert(Currency currency) {
            return currency.toString();
        }
    };

    Converter<String, Currency> stringToCurrency = new Converter<String, Currency>() {
        @Override
        public Currency convert(String s) {
            return Currency.getInstance(s);
        }
    };

    return new CustomConversions(Arrays.asList(currencyToString, stringToCurrency));
}

（很抱歉，我无法将此答案作为评论添加到 Oliver 的答案中。Stackoverflow 不会让我这样做。）

【讨论】：

【解决方案2】：

Spring Data MongoDB 对象映射系统目前不支持开箱即用的 Currency 类型。您可以通过提供核心 Spring Converter 作为 described in the reference documentation 的自定义实现来教 Spring Data MongoDB 如何转换该类型的实例。

public class CustomMongoConfiguration extends AbstractMongoConfiguration {

  @Bean
  @Override
  public CustomConversions customConversions() {

    Converter<Currency, String> currencyToString = source -> source.toString();
    Converter<String, Currency> stringToCurrency = source -> Currency.getInstance(source);

    return new CustomConversions(Arrays.asList(currencyToString, stringToCurrency));
  }
}

由于转换为String 似乎很简单，因此我创建了a ticket 以在即将发布的 Spring Data MongoDB 版本中解决。

【讨论】：

感谢您的回答和更新。还有一个问题，您可以看看stackoverflow.com/questions/35220287/…
感谢您关闭问题 :)
@DinkarThakur, @Oliver Gierke 我也面临同样的问题。但建议的答案对我不起作用。 customConversions() 在以下行给出空指针异常：new CustomConversions(Arrays.asList(currencyToString, stringToCurrency));。我不知道我在这里缺少什么。你能帮帮我吗？