Jooq fetchTo类java.util.LinkedHashMap不能强制转换为类

Question

给出此SO线程中给出的最后一个示例。

我得到这个错误：

java.lang.ClassCastException: class java.util.LinkedHashMap cannot be cast to class com.example.dtos.UserElement (java.util.LinkedHashMap is in module java.base of loader 'bootstrap'; com.example.dtos.UserElement is in unnamed module of loader 'app')

我应该使用jooq会满意的特殊映射器吗？

欢迎任何帮助

编辑：

Jooq版本：3.14.3 Postgres：11

ctx.select(
    USERS.ID.`as`("id"),
    USERS.USERNAME.`as`("name"),
    field(select(jsonArrayAgg(
        jsonObject(
            jsonEntry("id", USER_ELEMENT.ID),
            jsonEntry("name", USER_ELEMENT.ELEMENTS)
        )
    )
).from(USER_ELEMENT).where(USER_ELEMENT.ID
    .`in`(
        select(USER_ELEMENT_ACTION.USER_ELEMENT_ID)
            .from(USER_ELEMENT_ACTION)
            .where(USER_ELEMENT_ACTION.USER_ID.eq(USERS.ID))
        )
    )).`as`("elements")
).from(USERS)
.apply { if (condition != null) where(condition) }
.fetchInto(UserRoles::class.java)

dto公司

data class UserRoles(val id: Int, val name: String, val elements: List<UserElement>?)
data class UserElement(val id: Int, val name: String)

我也尝试过使用SimpleFlatMapper

ctx.configuration().set(JooqMapperFactory.newInstance().newRecordMapperProvider())

但是得到

MapperBuildingException: Could not find Getter for JooqFieldKey{field="elements", index=2} returning type

我正在使用spring boot，以下是我对jackson的依赖：

implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.10.5")
implementation("com.fasterxml.jackson.core:jackson-databind:2.10.0")

堆栈跟踪：

java.lang.ClassCastException: class java.util.LinkedHashMap cannot be cast to class com.example.dtos.UserElement (java.util.LinkedHashMap is in module java.base of loader 'bootstrap'; com.example.common.dtos.UserElement is in unnamed module of loader 'app')
at com.example.dao.UserDao.findUserAuthorities(UserDao.kt:103) ~[main/:na]
at com.example.service.auth.AuthService.getUserDetailByUsername(AuthService.kt:34) ~[main/:na]
at com.example.security.AuthUserDetailService.loadUserByUsername(WebSecurityConfigurer.kt:58) ~[main/:na]
at com.example.security.jwt.JwtRequestFilter.passAuthToTheSecurityContext(JwtRequestFilter.kt:48) ~[main/:na]
at com.example.security.jwt.JwtRequestFilter.doFilterInternal(JwtRequestFilter.kt:35) ~[main/:na]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.3.5.RELEASE.jar:5.3.5.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:93) ~[spring-boot-actuator-2.3.5.RELEASE.jar:2.3.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

Answer 1

jOOQ 3.14增加了对通过gson或Jackson开箱即用将JSON映射到任意类的支持。这在这里记录：https://www.jooq.org/doc/latest/manual/sql-execution/fetching/converter-provider

请注意，这是一个按列数据类型转换功能，由jOOQ的DefaultConverterProvider调用，而不是RecordMapper功能。经过更多讨论，这似乎是RecordMapper中的一个错误，它没有为Jackson提供尽可能多的泛型类型信息：

• https://github.com/jOOQ/jOOQ/issues/11008
• https://github.com/jOOQ/jOOQ/issues/11213

该错误已在jOOQ 3.15.0和3.14.10中修复