可选列表的 Bean 验证

Question

我正在使用 Bean 验证和 Spring-boot 2.0.2，它在所有情况下都按预期工作，除了列表/映射属性是可选的情况下。例子：

@Value
public class Address {

    @Pattern(regexp = "[^\\d]*")
    private final String street;

    private final int number;
}

带有可选列表的类：

@Value
public class Company {

    private final String name;

    private final List<Address> offices;

    public Optional<List< @Valid Address>> getOffices() {
        return Optional.ofNullable(offices);
    }
}

控制器

@ValidatedRestController
@RequestMapping("/api/omnichat/1/validation/test")
public class ValidationTestController {

    @PostMapping
    public Company createCompany(@RequestBody @Valid Company company){
        return company;
    }
}

我收到以下错误：

org.springframework.beans.InvalidPropertyException: Invalid property 'offices[0]' of bean class [com.infobip.ott.sender.transactional.validationTest.Company]: Illegal attempt to get property 'offices' threw exception; nested exception is org.springframework.beans.InvalidPropertyException: Invalid property 'offices[0]' of bean class [com.infobip.ott.sender.transactional.validationTest.Company]: Property referenced in indexed property path 'offices[0]' is neither an array nor a List nor a Set nor a Map; returned value was [Optional[[Address(street=givenStreet2, number=19)]]]
    at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:707)
    at org.springframework.beans.AbstractNestablePropertyAccessor.getNestedPropertyAccessor(AbstractNestablePropertyAccessor.java:839)
    at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyAccessorForPropertyPath(AbstractNestablePropertyAccessor.java:816)
    at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:610)
    at org.springframework.validation.AbstractPropertyBindingResult.getActualFieldValue(AbstractPropertyBindingResult.java:104)
    at org.springframework.validation.AbstractBindingResult.getRawFieldValue(AbstractBindingResult.java:284)
    at org.springframework.validation.beanvalidation.SpringValidatorAdapter.getRejectedValue(SpringValidatorAdapter.java:296)
    at org.springframework.validation.beanvalidation.SpringValidatorAdapter.processConstraintViolations(SpringValidatorAdapter.java:152)
    at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:119)
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.validate(ValidatorAdapter.java:69)
    at org.springframework.validation.DataBinder.validate(DataBinder.java:871)
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.validateIfApplicable(AbstractMessageConverterMethodArgumentResolver.java:260)
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:136)
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:124)
    at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:161)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:131)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
    at javax.servlet.http.HttpSe`enter code here`rvlet.service(HttpServlet.java:790)
    at enter code hereorg.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1655)
    at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:215)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
    at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at org.eclipse.jetty.server.Server.handle(Server.java:531)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102)
    at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:760)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:678)
    at java.base/java.lang.Thread.run(Thread.java:844)

发生这种情况是因为 AbstractNestablePropertyAccessor 无法解开可选内容。我找到了这个。解决方案之一是返回空列表而不是可选列表，但就我而言，我想要空可选列表。有没有其他解决办法。

Answer 1

一种解决方案是通过删除 来“恢复”Java Bean 约定Optional，并添加一个返回Optional包装字段的附加方法。

@Value
public class Company {

    private final String name;

    private final List<Address> offices;

    public List< @Valid Address> getOffices() {
        return offices;
    }

    public Optional<List<Address>> getOfficesAsOptional() {
        return Optional.ofNullable(offices);
    }
}

getOffices() 但如果必须返回一个Optional方法而不是另一个方法，则此解决方案可能不合适；例如，如果Company是一个实体（模型）以及一个表单对象，则getOffices()必须返回一个Optional正确的数据库序列化。

我通常将实体 ( @Entity) 和表单对象（带javax.validation注释的 POJO）分开以防止出现这些问题。