Spring Data JPA WITH Kotlin

@Entity 注解的实体类，必须要有一个默认的无参构造函数。

否则：

异常消息: No default constructor for entity: : com.ak47.cms.cms.entity.StockIndex; nested exception is org.hibernate.InstantiationException: No default constructor for entity: : com.ak47.cms.cms.entity.StockIndex

异常堆栈信息：

org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:314)

org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:225)

org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:500)

org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:61)

org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:217)

org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:153)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

org.springframework.data.repository.core.support.MethodInvocationValidator.invoke(MethodInvocationValidator.java:99)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)

com.sun.proxy.$Proxy111.findAll(Unknown Source)

com.ak47.cms.cms.controller.ApiController.stock_index(ApiController.kt:24)

sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

java.lang.reflect.Method.invoke(Method.java:497)

org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)

org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)

org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:871)

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:777)

org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)

org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)

org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)

org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)

org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:870)

javax.servlet.http.HttpServlet.service(HttpServlet.java:635)

org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:855)

javax.servlet.http.HttpServlet.service(HttpServlet.java:742)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:119)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)

org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)

org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)

org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)

org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)

org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)

org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)

org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)

org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)

org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)

org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)

org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)

java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

java.lang.Thread.run(Thread.java:745)

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代码正确写法:

package com.ak47.cms.cms.entity

import java.util.*
import javax.persistence.*

@Entity
class StockIndex {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    var id: Long = -1

    @Column(name = "index_code", unique = true)
    var index_code: String = ""

    @Column(name = "prod_name")
    var prod_name: String = ""


    @Column(name = "last_px")
    var last_px: String = ""


    @Column(name = "px_change")
    var px_change: String = ""


    @Column(name = "px_change_rate")
    var px_change_rate: String = ""


    @Column(name = "price_precision")
    var price_precision: String = ""

    var gmtCreated: Date = Date()
    var gmtModified: Date = Date()


    override fun toString(): String {
        return "StockIndex(id=$id, index_code='$index_code', prod_name='$prod_name', last_px='$last_px', px_change='$px_change', px_change_rate='$px_change_rate', price_precision='$price_precision', gmtCreated=$gmtCreated, gmtModified=$gmtModified)"
    }


}